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Archive-name: food/sourdough/faq
Posting-Frequency: 18 days
Last-modified: 2006/10/30
URL: http://www.nyx.net/~dgreenw/sourdoughfaqs.html
Subject: 1. Introduction and Where are the FAQs?
This FAQ is a collection of excerpts from past postings to
rec.food.sourdough. They answer frequently asked questions.
The objective of this FAQ is not to duplicate information that is
easily available in the several excellent FAQs; Starter Doctor FAQ,
basicbread FAQ, and sourdough Recipes FAQ and other archived
information already in existence at the unc archive site pointed to
and hot linked by URL;
http://www.nyx.net/~dgreenw/sourdoughfaqs.html
This URL also has additional information on starter sources and a
growing number of links to resources other than the archive site.
If you are using an ftp client the ftp archive site only is located at;
'sunSITE.unc.edu' path pub/academic/agriculture/rural-skills/food/sourdou=
gh/.
FTP appears quite limited in number of connections permitted so I
recommend using the http server at unc pointed to by
http://www.nyx.net/~dgreenw/sourdoughfaqs.html if you can.
A hypertext copy of the latest version of this FAQ is at URL;
http://www.nyx.net/~dgreenw/sourdoughqa.html
In addition to being posted in rec.food.sourdough, rec.answers, and
news.answers monthly this faq, along with the other 3 regularly
posted FAQs, is also archived at rtfm.mit.edu (18.181.0.24) in the
directory
/pub/usenet/news.answers/food/sourdough/
as 'faq', 'starters', 'basicbread' and 'recipes'. This is useful if
you do not have web access: the rtfm.mit.edu archival site permits
both ftp and email retrieval of these files.
To obtain these faqs, first try ftp to rtfm.mit.edu and look under
that directory.
If ftp does not work from your site, then try the mail server: send
email to mail-server@rtfm.mit.edu with one or more of the following
lines in the body of the message:
send usenet/news.answers/food/sourdough/faq
send usenet/news.answers/food/sourdough/starters
send usenet/news.answers/food/sourdough/basicbread
send usenet/news.answers/food/sourdough/recipes
Contributions to this FAQ gratefully received.
Authors are noted in the last section (99). The authors' first names
are at the end of each of their contributions.
------------------------------
Subject: 2. Table of Contents
1. Introduction and Where are the FAQs?
2. Table of Contents
3. What is the protein or gluten content of various flours?
4. What are some books on bread?
5. What is gluten and how does kneading develop it?
6. How do wild and commercial yeast differ?
7. Can I make bread without salt?
8. How do I stop my sourdough bread from flattening?
9. Can I use chlorinated water with my starter?
10. Does temperature of the starter have an effect on flavour?
11. What is diastatic malt?
12. What is meant by % hydration of a dough?
13. What is a sponge?
14. What is the difference between 'Classical' and 'Modern' sourdough?
15. How do I make soft buns?
16. How should I feed my starter for best results?
17. Are all starters the same?
18. What about Nancy Silverton's latest book?
19. How do I get that great crust?
20. How much starter do I need?
21. Sourdough Science 101 or How are the sourness and leavening of
starters related?
22. What is the Microbiology of San Francisco Sourdough?
23. What about Ed Wood's latest edition of his book?
24. How can I start a starter from scratch?
25. How do I get holey, sour, moist and long keeping bread?
26. Is slashing of loaves aesthetic or functional?
27. How do lactic bacteria affect sourdough bread?
28. What is hooch? Refrigerator hooch? What do I do with it?
29. How can I determine the proportion of flour and water to use in
my starter and dough?
30. How can I ship my starter to someone else?
31. How do I get that lofty loaf?
32. What is San Francisco Sourdough?
33. What temperature should my starter be for best results?
34. Can I freeze or dry my starter?
35. What happens if I start my starter with commercial yeast?
36. What do all these baker's terms like poolish, biga, chef, mean?
37. What is the relationship between temperature and sourdough activity?
38. Is there a glossary of rec.food.sourdough terms?
39. What factors affect microbial growth in sourdough
40. Should I use an established starter or make my own starter?
41. Can I use metal utensils with sourdough?
42. What is a good source for technical information on sourdough starters=
?
43. How do I convert yeast bread recipes to SD recipes?
44. What is meant by a "fully activated" starter?
45. What about Dan Wing's new book "The Bread Builders"?
46. What's all this about natural leaven and L. sanfranciscensis?
47. How does one measure the ph of sourdough, and what is the effect
of different ph's?
48. Should I use more than one rise for my bread?
49. What is Salt Rising Bread?
99. Authors
------------------------------
Subject: 3. What is the protein or gluten content of various flours?
Cake flour is typically 7-9% protein; pastry, or cookie, ~9-10%; all
purpose, 10-12%, bread, 12.5-13.5%, clear and high gluten, 14-15%;
gluten "flour" (actually refined gluten), 45%. The protein consists
of ~80% gluten, and the gluten of cake flour is weakest, and bread
and high gluten flour the strongest, and the intermediate ones
increasingly stronger. Gluten is more of less made up of equal parts
of gliadin and glutenin.
Gluten strength definition and measurement are not entirely well
understood, even by cereal chemists. Generally, you want the most
protein and strongest gluten for bagels and breads that also use
other poor or non-gluten flours such as rye or oat; moderately strong
for all wheat bread; weaker for pastries and cookies; still weaker
for cakes such as pound cakes; yet still weaker for "high-ratio,"
rich cakes; and weakest for angel food cakes. One of the quality
tests for soft wheat flour is the "cookie spread test, which is one
measure of this. There are also farinographs, elastographs, and
whatnot to further attempt to measure this elusive property.
Fortunately, with most flours, increasing protein content goes along
with increasing gluten strength.
-Jeff
See also:
Flour -- A Treatise: http://www.theartisan.net/Flours_One.htm
Flour Test -- Flours of America: http://www.theartisan.net/flour_test.htm
------------------------------
Subject: 4. What are some books on bread?
I happen to be passionate about bread and own approximately 25 books
on bread and have closely read numerous others. I will try and give
you a tour of some of the books on bread, one
introductory/intermediate, two current books focussing on "artisan"
type breads and a few in the specialized to advanced category to give
you a flavor of some of the books out there.
The Laurel's Kitchen Bread book - A guide to Whole-Grain bread making
by Laurel Robertson, Carol Flinders and Bronwen Godfrey is perhaps
one of the best introductions to bread making.
The books is aimed at people who want to bake with whole-grains but
there is no reason you cannot use the principles with whatever form
of flour you choose. She begins with a loaf for learning, thoroughly
explains the principles of what you are trying to achieve (for
example most books say something vague like "knead till elastic" she
give you an objective end point - when dough is sufficiently kneaded
you should be able to stretch the dough paper thin (insufficiently
kneaded dough will tear or break long before you can stretch it this
thin). She covers a wide variety of breads and methods, explains the
effects of various ingredients and additives and has some unique
material - for example she extols a Flemish "Desem" starter. She has
tables to help you find recipes that fit into your schedule and adapt
recipes to any baking schedule you choose. Everything she says is
accurate (no small feat if you consider some of the stuff below).
From the point of view of sourdough she is not a purist & in the
context of a general book on bread I have no major quibble with that.
The only flaw if you can call it one is there are no glossy pictures
to inspire you. This is an issue because unfortunately many modern
books have awfully good pictures that illustrate some important
points (e.g. what does an "open" crumb vs fine crumb look like etc).
It is sparsely referenced but has a few very authoritative references
(Pyler "Baking Science and Technology" for example). A must buy for
anyone learning to bake.
The next three books focus on artisan type or regional breads:
Joe Ortiz in the Village Baker says that in a trip to France he got a
recipe for "pain ordinaire" and thought finally he had the long
sought "secret recipe" only to discover that it was identical to the
one he was already using! To him the lesson was the process was the
important part not merely the ingredients and a good loaf was the
result of successful mastery and manipulation of every step from
choice of ingredients to mixing to baking. I think this is a good
criterion to use to judge the current crop of bread books ( as well
as older ones) - does the book give you sufficient information to
understand the process so you can manipulate it to suit your own
needs and tastes. I think the Ortiz book is very successful in this
regard. It is really a condensation of several French masterpieces
(cited in his bibliography) and is thus is a valuable resource for
someone who is interested in Raymond Calvel or Lionel Poilane
opinions on bread but cannot read the French originals. He explains
the 3 basic kinds of dough (sponge, straight and sourdough). The
importance of a number of variables and their effects like water
(how wet the dough is) yeast, mixing conditions, temperature, wheat
and how they end up altering the product. There is an incredible
amount of information. Some of the info is laid out directly.
Other parts will need lots of work on your part - he tells you a
certain manipulation will affect say crumb but doesn't tell you why
or in what direction - it does serve as a basis for experimentation
however. I suspect he is not always clear about explaining the whys
because he is an empirical baker. Having read some of the more
Technical books by Pyler, Pomeranz, Stear etc I have come to
understand the reasons why particular manipulations work. In short
this book glorifies the method and is invaluable if this is what you
want.
No baker will agree with all his opinions on what a desirable
approach to bread is, for example he recommends building sourdough
starters relatively firm which is unlikely to pack the maximum flavor
one can out of a sourdough (there are several good reasons to have a
firm starter if one is only interested in good leavening). The other
negative to me is that approximately a third of the book has recipes
scaled up for the professional. This is an interesting curiosity but
a waste to most home bakers. It has a good bibliography with
classic primary sources. One could learn a lot from this over a long
time - every rereading should uncover something new which could serve
as the basis for experimentation. Not all of his opinions are
correct, and there are technical missteps but since I am saving my
venom for Daniel Leader I will pass on to him.
Bread Alone - Daniel Leader and Judith Blahnik. I am lukewarm about
this book. It is a very slick presentation that will seduce you with
the romance of bread baking. It strings together a number of
anecdotes in a racy style that is good entertainment. You will come
out longing for a brick oven that he very skillfully mystifies and
glorifies. It has pictures of very attractive loaves that are
highly motivating. It extols the virtues of organic flour (a passion
I share). Many of the recipes are on the trendy end - Country style
loaf with figs and cognac and hazelnuts. The same with cilantro and
cornmeal and coarse pepper etc. By the way he adds an additive like
cilantro and cornmeal and considers this a new recipe in my book
these should be considered variations. The book is very heavily
padded with these variations and in actuality is very lean. I am not
particularly impressed because only my imagination limits what
concoctions I can come up with i.e. the hip recipes should not
motivate you to buy this book. In fact it is the hipness that irks
me. For example, he uses french terms for commonly used baking
terms. Thus a sponge is a poolish, a sourdough is levain and so on.
In no place does he explain the parallels and studiously avoids the
common english terms. This is a slick way of packaging old wine in
new bottles.
He is factually wrong in a number of places. For example, he says
that sourdough fanatics falsely treasure starters and he will
demystify the process. He gives directions on starting your own
starter and suggest adding yeast " as a magnet to attract the wild
yeasts" -pure bull! Similarly he has a recipe for San Francisco
Sourdough but uses the homemade starter. San Francisco Sourdough is
not a process but requires the presence of a true starter with the
characteristic organisms of San Francisco Sourdough - Candida milleri
and Lactobacillus sanfrancisco. It is as likely that the ""Hearty
Burgundy" of Ernest and Julio Gallo resembles the wines of Burgundy
France as a homemade starter will have these particular organisms.
(To be fair to Daniel Leader almost all books on bread commit this
mistake in the obligatory "San Francisco Sourdough" recipe).
On page 42 he says flour is "bromated" with potassium! (For you non
scientists potassium bromate is used - with the bromate doing the
brominating not potassium! Then on page 50 he has the strangest
definition of first rise and second rise I have ever seen - he claims
the yeast feed on free sugar in the first rise and the yeast release
sugar from starch in the second rise. In truth there is very little
free sugar in flour and once depleted the yeast are dependant on
release of sugar from starch to continue to do their thing. When
exactly this happens depends on the dough formulation, fermentation
time and temperature etc etc. In fact in his lean long fermented
poolish the yeast are very definitely living of starch & no rises
have occurred at all! It is simply stupid to use his definitions. I
heap so much venom because he is a graduate of the Culinary Institute
of America, professional baker etc. and should have a better command
of the facts. I would not nitpick if I found stuff like this in Marge
Schlee's "Baking with Schmecks appeal !"
Another aspect of the book that I dislike is that he repeats the most
basic information for each step for every single recipe (many of
which are variations in the form of an addition to a basic dough).
For example he has three standard paragraphs on baking that tell you
your rack should be in the center of the oven. Do not spritz the
electric light bulb etc. This repetitious stuff occupies at least
half the printed pages of the book - the book thus has the mere
appearance of heft but is in fact quite thin. (Others may like this
because you can start at any recipe in a non linear fashion). It has
no bibliography and is lean on technique. To me the book is more
sizzle than steak - it is worth reading but owning?
The Italian Baker - Carol Field. In the Joe Ortiz vein. A
masterpiece on Italian Bread. Carol Field is less authoritative than
Ortiz in some respects - she is a cook book author with 5-6 published
books on the history of Italy and Italian foods. Her cookbook author
roots show through occasionally. For example on page 41 talking
about yeast she says: "Bakers, who have noses like doctors or
pharmacists, insist you can cut into the yeast and smell if it's
right. The really expert say that if you set your ear right next to
it, you can hear the little "tic-tac" of its growing." While poetic
this is pure nonsense. Fortunately, there is not much drivel like
this in the book. The reason I like the book is she tells you what
the character of the dough is like - wet, firm etc. All too often
this is ignored in most books on bread when in fact it is one of the
major ways of controlling the nature of the loaf you produce. The
minor negative is she repeats mixing information by hand, mixer and
food processor for each recipe. This is generally unnecessary except
in some rare cases.
Il Fornio - Author? Light version of Carol Field. In fact owner of
Il Fornio chain Carlo Veggetti was the person that arranged the
meetings with regional Italian bakers for Field's own research.
Elizabeth Davids "English Bread and Yeast Cookery". Available in an
English version with imperial and metric measures and an American
edition with a conversion to volume based measures (cups vs weights).
The books is divided into two parts - "History and Background" and
the second "Recipes". This is an interesting book to a scholar
because it traces several historical roots of English Bread - it is
not as some people think an encyclopedia on bread in general. It is
written in a humanistic style & its virtue lies solely in its
research into the historical aspects of English bread and breadmaking
(bibliography of 200+). This aspect of the book makes a fascinating
read with interesting plates and illustrations.
Its practical utility is a different matter. For example, she has a
chapter on French Bread, goes on to enumerate the difficulties of
making french bread and the difference between French and English
flour and then throws up her hands and says despite all I've said if
you want to bake French Bread consult Mastering the Art of French
Cooking by Julia Child et al. ! She then goes on to trace the roots
of French Bread in England from 1654 to the twentieth century via
10-12 historical recipes. Clearly this is aimed at a pedant not an
amateur. Most of the recipes are historical in nature and make
interesting reading but it is not a good place to start to learn how
to bake bread. Please note I am not saying there is nothing of
practical utility (there is a lot) it is just buried in a lot of
material. Despite the praise universally heaped on this book (much
of it is deserved) I feel it has an equal number of deficiencies that
are glaring. For example, she has a section on Malt, declares she
hates the taste of it in bread, goes on to say some bakers like it
for good rises & leaves one thoroughly confused. She neglects to
mention how and why it works and the distinctions in malt (Malt can
be diastatic or non-diastatic. Non diastatic is simply added as a
sweetener, diastatic malt breaks down the starch in dough to yield
sugars on which the yeast can feed. Having some around in long
fermented breads is very important). It seems amazing to me that she
will spend chapters on the "Assize System" & then neglect to tell you
something of great practical importance. Similarly, her basic recipe
for bread has almost no mention of kneading at all!
The Breads of France - Bernard Clayton. Bernard Clayton has been
looked upon as the doyen of American Bread for reasons I cannot
fathom. The material when published was new and novel.
Unfortunately, the book is sort of pointless since there appears to
be no correlation between his description of a bread and the recipe
that follows. For example, he has a recipe for the famous Poilaine
loaf (actually describing a bread made by the father of the now
equally famous Lionel Poilaine), says it is made from whole wheat and
then uses next to no whole wheat in his recipe! It is therefore
pointless to buy a book of this sort. His complete book of breads
has a vast array of recipes again in a boring style. Essentially
both books are recipe repositories & the recipes are of dubious
authenticity. The tedium in the Breads of France is relieved by a few
photographs and vignettes of the bakers or history behind some of the
breads.
Special and Decorative Breads a two volume set by Roland Bilheux,
Alain Escoffier, Daniel Herve and Jean Marie Pouradier (Volume 1) &
Volume II is authored by Alain Couet and Eric Kayser. There is some
overlap between Vol 1 & II, Vol 1 mainly focuses on traditional
breads while Vol II has Viennese pastries, Croissants Brioches etc.
This is a translation of a French original has much distilled wisdom
and incredible photographs of ornamental and decorative breads. It
has very concise information that is generally very precise - they
define the exact hydration for stiff (58-60%) to soft & sticky
(65-67%) doughs with five intermediate steps. This is useful because
they either explicitly say the dough is mixed at xx hydration or if
they use a word like moderately firm you know precisely what they
mean. Its negative - very specialized all recipes are scaled for a
professional baker i.e. yield 25-100 lb of dough and major $$ each
volume is about $70. I am glad I own them but they are so
specialized that they may not be worth the $$ but it is a very good
set of books to thumb through if only to improve your presentation.
World Sourdough from Antiquity: by Ed Wood. Out of print (new
edition in print now - dg) but may be available in some libraries. A
very cynical view would suggest this book was probably published as a
marketing vehicle for the starters that he sells through his company
Sourdough International. A more generous view would be that Dr. Wood
genuinely wants to spread the sourdough gospel. I do not know what
motivates him but in fact I feel that the Woods have provided a
tremendous service to the community by amassing these starters.
Simply being able to buy a "fast" starter vs a "slow" starter allows
you to refute the view of Leader or Joe Ortiz that starters are not
substantially different. The book gives a reasonable explanation of
several aspects of baking with sourdough. It is probably the best
book on sourdough for a non technical audience. Treasure trove of
recipes from Egypt, Bahrain, Saudi Arabia i.e. the area where all
bread making probably originated (and less interestingly since this
material is almost universally available, The Yukon, France, San
Francisco, Austria, etc). He uses a number of grains and flours in
his recipes demonstrating his awareness of what a true country bread
is and a certain adventurous spirit with respect to ingredients. It
has been built up so much on this group that it will probably prove
underwhelming - it is the best non technical book on sourdough but is
not necessarily the best book on bread in general.
-Roland
------------------------------
Subject: 5. What is gluten and how is it developed?
What people call gluten is the formation of linkages between glutenin
and gliadin. The "development" of dough consists of the formation of
these bonds. These proteins have SH groups on them than can be
linked into S-S groups. Just letting the sponge sit allows the
reaction to proceed which is why the French call this "long kneading"
i.e. you do nothing and the gluten is partially, developed. This is
why, in a post to Bruce Hudson on sponge type breads I said that
dough could be developed mechanically, (by kneading), chemically (by
mixtures of oxidants and reductants) or fermentatively. Very few
people realize that you can develop dough in all three ways: they
learnt kneading was very important and are fixated on it. In fact
kneading is absolutely essential only for straight dough breads.
Kneading, develops gluten by stretching out the proteins, &
increasing the rate at which, the molecules collide and the reaction
occurs. Kneading also forms an ordered cohesive mass. The reaction
remains essentially, a chemical reaction. The virtue of kneading is
the mass is very uniform and the gluten can be developed very
extensively (homogenous and extensive cross-linking) to give very
strong loaves - which will rise spectacularly and have good
mechanical strength so you can make free form loaves fearlessly.
Most straight dough recipes develop all the gluten by kneading.
Many sponge type breads fall into the category where a lot of the
development is achieved by fermentation which allows less or in
Jeff's case no kneading. Allowing the gluten to develop by
fermentation, simply means that you give the dough sufficient time to
let the chemical reactions occur spontaneously i.e. the linkages will
form slowly over time. The lattice of cross-linked gluten that forms
is not necessarily, as strong or as fully developed but this is
undoubtedly what Jeff is aiming for: French country bread is
characterized by an uneven crumb - by minimizing mechanical mixing he
keeps the mass non homogenous. The simple actions of the original
mixing, punch downs, shaping etc. also add a dimension of mechanical
development. Relying solely on fermentative development means the
gluten will not be completely developed, the loaves will be weaker
i.e. you might have a hard time making a large free form loaf with
it. By combining some fermentative and mechanical development you
can dramatically, alter the range of textures of your bread: there
is an infinite spectrum of how long you ferment and how long you and
how intensely you knead. By controlling these two you produce
dramatically, different breads. This is one of the secrets to the
whole range of "French" breads. Jeff is at an extreme when he uses
no mechanical development at all. Since he seems to make mainly
baguettes this is easy to do - you do not need a very strong dough to
hold its form in a baguette. I would be interested to know if your no
knead doughs allow you to form large free form loaves.
Several dough improvers including the so called natural conditioners
like ascorbic acid (Vitamin C, you will see that it is added to
nearly all commercial flour) are oxidants that facilitate the
reaction. Similarly, the french add fava bean or soy bean flour
which has a lipoxygenase which oxidizes flour i.e. takes SH groups
and make them S-S i.e. forms linkages and also bleaches the
carotenoid pigments for a whiter crumb. These conditioners have a
dramatic effect on the rate of the reaction and the extent to which
the reaction occurs. I learnt this very dramatically, when I bought
my grain mill: Flour that you buy has been aged or brominated (to
oxidize the flour which as explained above forms gluten strengthening
cross links & bleaches the carotenoid pigments). Freshly milled
flour does not have the benefit of these "improving" i.e. gluten
strengthening actions. I noticed that my dough would "fall apart"
when kneading very very quickly. This was because the flour was not
sufficiently oxidized when freshly milled. This was fixed by adding
vitamin C and freshly milled soy bean flour (I simply added back
oxidants! It is still not as strong as the strongest flour I worked
with. No additions will allow you to turn out a decent loaf too -
you just need to know how to handle it).
In some commercial, operations the dough is developed by a long list
of chemicals (check any supermarket bread label) that are essential
oxidants or reductants and thus facilitate the reaction. This
combined with a very intensive short 1 min mixing develops the dough
completely!
Just as the cross-links can form so can they break down. This is
referred to as the dough becoming "slack" - very long fermented
doughs become slack because the cross-linking process reverses
itself. In addition there are a number of chemicals naturally,
present in dough or from breakdown of yeasts that promote the
breakdown of the cross-links. This is one of the reasons you cannot
hold the dough infinitely long in a fermentation to improve its
flavor. In fact the reason why dry yeast should be reconstituted at
104-114 F is because at lower temps the yeast lyse and release
glutathione which affects the oxidation reduction reactions and
reverses them leading to slack or weak doughs.
-Roland
See also
------------------------------
Subject: 6. How do wild and commercial yeast differ?
The yeasts role in a sourdough starter is to leaven the bread (i.e.
produce gas). Commercial yeast is very good at this job since that
is all it was selected to do. Common bakers yeast that most normal
people have access to is slightly acid sensitive and most sourdough
yeasts are moderately acid resistant. Commercially on a bakery level
you can obtain yeasts that are acid resistant and a host of other
desirable properties (freeze tolerance, sugar tolerance etc.).
In a laboratory environment a common medium for a laboratory form of
bakers yeast is Yeast nitrogen base whose pH is 5.4! Most sourdoughs
have a pH at the end of the fermentation of around 3.5 - 4.2. Since
the scale is logarithmic this is relatively large difference.
The acids produced by lactobacilli definitely slow the yeast down (be
they commercial or sourdough). The natural yeast are obviously more
tolerant of acid. You could overcome the acid sensitivity by adding
more yeast or proofing longer. This is not to say I advocate doing
it - I am merely pointing out it can be done. You have to be
judicious in how much yeast you add since too much will cause the
bread to be overwhelmingly yeasty in flavour.
Another aspect of leavening sourdough breads is that the gluten is
attacked under acid conditions through the action of several acid
proteases. Thus the ability of the individual cells of the gluten
net to hold gas is compromised. If you let your dough develop to such
a point it will obviously rise very feebly no matter what your source
of leavening is - wild or commercial since any gas produced will
simply leak away.
One of the pleasures of sourdough is understanding the rhythms of
both the yeast and lactobacilli and holding them both at just the
right level - optimal acidity, optimal flavour (I suspect when most
people here say they want their bread more sour what they actually
mean to say is more flavour full - a very sour bread can be
excruciatingly unappetizing) and optimal leavening. This is achieved
by manipulating the starter to maximize the number of organisms,
varying the "wetness" of both starter and dough and controlling time
and temperature of all stages.
I should point out that if you do play with commercial yeast there is
a very good chance that you will pollute your starter and you
obviously do not want to add it to the starter i.e. should you use it
you definitely need to develop a procedure to maintain the starter
uncontaminated.
Commercial bakeries oftentimes use yeast as a leavening in a
sourdough not because they do not know better but because they
require very predictable rises - they may have hundreds of pounds of
different breads developing at different rates and have to hit the
oven in fairly tight windows. A commercial leavening in this context
can be controlled far easier. Obviously an equal number of bakeries
develop the bread naturally but this requires more skill, time and
ultimately for the baker $.
To address the original point of this thread though: a starter made
from commercial yeast performing better than an established starter
(I believe Russian from Sourdough International). If I remember
correctly, the poster mentioned they had obtained the starter second
hand. Based on my experience with home started vs purchased starters
I suspect that the starter you obtained is probably far from the
original sold by SI. I have had the most consistent results with
legitimate "established" starters.
I should point out however that I have noticed a deterioration in
some starters over time - I have not figured out the root of the
problem since I was not careful enough to pinpoint exactly when the
change occurred but I have found a starter that I loved evolving into
a dud. Obviously this means contamination/loss of a favorable
lactobacillus. I was originally very careful when I bought the
starter and would boil the water used to feed the starter (and let it
cool!) & once it was established decided it could fend for itself.
In hindsight I think this may have been an error in judgement: the
boiling apart from getting rid of any other unfriendly beasts
probably also got rid of chlorine etc. I suspect that this could
have been one of the things that did my lactobacilli in. Flour
obviously has organisms that you cannot get rid of and this is
potentially another source of contamination: lactobacilli have
several bacteriophages and produce bacteriocins that could have
killed my treasured lactobacilli (the reason I think I have lost
lactobacilli complexity is because the bread rises fine but the
flavour is middling). The starters from SI have predictably activity
peaks & the Russian is very fast, you could use this as a test to see
if what you have is still legitimate. I can vouch for the fact that
the Russian, Austrian and Bahrain rise as described in their
literature. Also since the Russian rises so fast you may be tempted
to bake the bread before the lactobacilli have had a chance to do
their magic. Among the above three starters I like the flavours of
the Austrian the best.
-Roland
------------------------------
Subject: 7. Can I make bread without salt?
Salt is of course very important in a dough. There are several
proteins in flour that together form gluten during mixing. Some of
these proteins are more soluble in salt water than fresh water.
Therefore, addition of salt helps to form a stronger gluten network.
Commercial bakeries often add salt at the very end of mixing because
it keeps the dough loose so that it will develop more quickly and
also does not inhibit the yeast during that brief period. Bread,
however, can be made perfectly well without salt.
-Troy
------------------------------
Subject: 8. How do I stop my sourdough bread from flattening?
A very important aspect of making sourdough is the amount of starter
used in the recipe and how long it has been since the starter
matured. Typically, about 20-40% of the total flour should come from
the starter. The higher the percentage of starter, the less proofing
time it will stand. In other words, if 40% of the flour comes from
starter, you may only be able to proof 3-4 hours before the loaves
flatten excessively, depending on the starter and degree of maturity.
I've never used Carl's starter, but since people like it I assume it
has fairly low levels of enzymes which make it more tolerant to
various baking procedures. Different lactobacilli have different
capacities to degrade flour and to make acid and therefore they act
differently in bread.
The standard methods to keep bread from flattening excessively
include reducing water, increasing kneading or adding ascorbic acid
(100-200 mg per 5 pounds of flour), making sure the starter is not
overly mature, and doing some of the fermentation as a "bulk"
fermentation. Bulk fermentation simply means that after mixing the
dough you let it sit for 2-3 hours at proofing temperature before
shaping the loaves. That will give the bacteria/yeast time to make
flavor and gas without having to worry about the loaves flattening.
Then the loaves are shaped and a final proof of 3-4 hours results in
a fantastic loaf with a more interesting internal and external
texture.
One other important reason why sourdough loaves may flatten is that
the starter is not fresh enough. When you feed your starter use the
smallest amount of old starter that you can while still getting a
very active ferment by the time you need to mix your dough. If the
old starter is very active I would use only 5-10% by weight as an
innoculum. Starters that are not fresh produce extremely slack
doughs. The type of flour you use will help, but will not completely
overcome the problem. If 20-30% of the flour in your dough comes
from starter you should be able to proof a free standing loaf for
many hours without flattening. I typically mix a dough, let it sit
for 3 hours, shape into loaves, and give up to 5 hours of final proof
with little flattening.
Water content for this type of loaf is 56-60% on flour.
-Troy
While flattening can occur from hydration (particularly with baguettes)
it mainly has to do with the fermentation and proof. Dough that is
over-proofed will collapse on itself when you try to slash it or, in some
extreme cases, if you even touch it. The reason for this is because the
gluten has been broken down by the bacteria and yeast that it can no
longer support the structure of the bread. Bread that is over proofed
will also be really sour. While some people like sour bread, it will
generally be at a detriment to your big, holey, irregular crumb. This
can also happen with your starter. A well proofed starter will have
doubled (atleast) in volume, be full of bubbles and will just be starting
to collapse on itself, but if you reached in a pulled some of it out, it
will still have thick strands of gluten keeping it elastic and
extensible. If it is proofed for too long, the gluten will break down
and you will eventually have a soupy mass that won't stretch at all
because it will be a liquid. If a loaf is proofed too long, it will
start to collapse when you try to slash it or when you transfer it to a
peel.
Hydration can be as high as 85% and while you won't be able to shape it,
you will be able to get really big holes without it flattening on you
even though the dough will seem flat before you bake it, it will puff up
in the oven.
-- Connor
------------------------------
Subject: 9. Can I use chlorinated water with my starter?
No. If you have chlorinated water, dechlorinate it first. The quick
way is with a carbon filter. You can also boil it or just let it sit
out uncovered 24 hrs, provided that your water treatment plant
chlorinates with free chlorine (as ~85% do), and not with the stable
form of chlorine, chloroamine. This cannot be boiled or evaporated
out.
Dechlorinated water is not just some yogurt and granola health food
nut idea, it is very important for the health of your culture and the
success of your sourdough baking. A microbiologist friend of mine
confirmed this observation with laboratory techniques.
-Jeff
------------------------------
Subject: 10. Does temperature of the starter have an effect on flavour?
Sourdough cultures from Europe tend to have many strains of
lactobacilli. Temperatures under 86 F favor L. brevis which produces
both lactic acid and acetic acid. Temperatures above 86 F tend to
favor L. plantarum which is homofermentative and only produces lactic
acid.
Other factors play a role in the acid profile: degree of hydration
(soft doughs favor lactic acid formation while stiff doughs favor
acetic acid).
The way the starter is built up into the final dough will affect the
absolute number and type of organisms and consequently the flavor
profile of the bread. German bakers have very complicated schedules
where they vary both stiffness of the dough and temperatures to build
their starters and thus alter the flavor of the bread.
I have no idea what organisms are present in the original posters
culture but if he is lucky playing with temperature and hydration and
different cultures may allow him to produce the flavor he wants.
-Roland
------------------------------
Subject: 11. What is diastatic malt?
Malt can be diastatic or non-diastatic. Non-diastatic is simply added
as a sweetener, diastatic malt breaks down the starch in dough to
yield sugars on which the yeast can feed. Having some around in long
fermented breads is very important.
-Roland
Mills will typically put in 1/10% malted barley flour (barley because
barley malt is cheaper than wheat malt) to provide diastase (enzyme),
which converts the starch in damaged starch granules to sugars that
are utilizable by the yeast over an extended ferment. The use of
more diastatic malt than this can result in slack, sticky dough, and
will not improve yeast action. Malt is not made from cooked grain,
but rather sprouted grain.
-Jeff
Diastatic malt powder is powdered malted grain, usually barley, but
wheat, and rice may also be malted. "Diastatic" refers to the
diastatic enzymes that are created as the grain sprouts. These
convert starches to sugars, which yeasties eat. Maltose, a simple
sugar that yeasties love is usually made in abundance by the enzymes.
Diastatic malt powder is available in some health food stores as well
as homebrew supply shops.
You can make your own: sprout a cup of wheat berries by covering
them with water in a jar for 12 or so hours, dump out the water &
rinse with clean water, and place the jar in a darkish, warmish,
place. Rinse the berries every day with clean water and return to
their place.
In 2-3 days they will begin to sprout. When the sprout is as long as
the berries themselves, dump them out on paper towels, dry them off,
and set on a cookie sheet in the sun for a day or so to dry out. Then
put the cookiesheet in a 100F oven for an hour or three. Do not let
the temp get above 130F or the enzymes will be destroyed.
Then grind the dried malted berries into flour, and use it in your
favorite recipe at a rate of approx. 1t. per loaf.
I did this for the first time last week, and the bread made with is
has a lovely wheaty note that was not produced in the past when I
used brewer's (barley) malt.
-George
------------------------------
Subject: 12. What is meant by % hydration of a dough
"Bakers Formulae" are based on the weight of flour which is assigned
100%. Any other material being added is expressed as a percentage of
this. Thus water may be at 55% to 60 to 65% of the the flour. If
you think in metric terms it is very easy each 1000 grams (1Kg) of
flour would need 600 grams of water for 60% hydration etc, similarly
salt may be added to 1-2% etc etc. So a bakers % is actually a very
slippery definition and not "correct" in scientific terms but they
understand each other.
The % hydration matters both when you feed/build your starter and in
the final dough. Studies show the maximum acid is built at 90%
hydration (during feeding/building).
-Roland
------------------------------
Subject: 13. What is a sponge?
A batter or soft dough containing all of the water, but only part of
the flour and (usually) none of the salt. The starter (or,
conservatively, part of the starter) is mixed into it, and thereafter
it is incubated (at some temperature between freezing and heat death)
until it gets frothy, at which time the dough is completed with
additional flour, salt, and usually some kneading.
-Dick
------------------------------
Subject: 14. What is the difference between 'Classical' and 'Modern'
sourdough?
In days of yore, all bread was sourdough. So, it wasn't called
sourdough unless it was real sour. The way to make it real sour was
to let a sponge sit for many extra hours, preferably warm.
Many people do that today when making sourdough bread. You can call
it "souring the sponge". The process favors the acid forming
bacilli, and lowers yeast activity. If you goof and the yeast
activity gets too low, you can always throw in some bakers' yeast for
the final rise. You also can get some rise by blowing the loaves up
on a hot stone, in spite that a real sour sponge may not have much
leavening activity.
Denizens of yore had no access to bakers' yeast, nor did they have
modern bread flours.
Today's bread flours, as well as having uniformly high gluten content
(typically 13%), also contain diastatic enzymes and dough
conditioners. The enzymes liberate sugars from starch allowing the
rise to go on much longer than otherwise would be expected. Dough
conditioners can have profound effects towards helping the gluten to
hang together long enough to support a phenomenal rise.
The result is that a kind of modern sourdough bread is now possible
that the yore people could not have anticipated.
A long rise allows that sourdough bread may be very light, and may be
baked quite effectively in bread pans in an ordinary oven (without a
stone). For this bread, a "sweet" (high yeast activity) (sourdough
yeast, that is) sponge is used. Acidity and flavor which typify
sourdough bread develop during the rise, not primarily in the sponge,
as is the the case in the alternative classical method. More and
more people are doing it this modern way.
But it is not clear to most people that two strategies are under
discussion here. People on track B should learn how to avoid advice
from track A people, and conversely. (Advice givers cannot be
controlled, since a new bunch is born each week.)
How to recognize:
Type A: "Let the sponge proof in a warm place for a long time". "A
sour (tangy) starter is needed." "Use King Arthur (no additives)
flour." "Use all purpose flour." "Punch it down (N) times, let it
double, slash, and toss it on a hot stone." "May be necessary to add
some dry yeast." (Per most bake books, FAQs here, and sourdough
packet instruction sheets.)
Type B: Starter is kept frothy, or activated to the frothy stage
before seeding the sponge. Sponge is developed to the frothy stage,
no longer. Use bread flour (malted, bromated or whatever). Bakers'
yeast is never used. Very little or no punching down. Slash (coupe)
before the rise. Volume quadruples, maybe quintuples, before the
bake. Special attention needed to avoid deflation if transferred to
a hot stone (but easy in tins). Special attention is needed to avoid
drying out during the long rise (which might be 12 hours in a cool
room).
-Dick
------------------------------
Subject: 15. How do I make soft buns?
The easiest way to get very soft silky buns is to use lots of pastry
flour (half pastry/half all purpose or bread) & plenty of fat in the
form of butter. This produces melt in your mouth types of buns.
People are generally obsessed with gluten content in wheat - if truth
be told you can make bread with pastry flour i.e. a gluten content of
8% or so. Naturally, the character of the bread is different. You
generally, want to match the character of the bread with the
character of the flour. Generally, people are very obsessed with
high gluten flours which do indeed produce lofty loaves but if not
worked properly can also produce rubbery loaves. Elizabeth David is
one of the few authors on bread, incidentally, who advocates looking
for flavour in flours rather than simply high gluten content - a
lofty loaf is a good loaf only from certain points of view.
Incidentally, buns and the like that I have baked with substantial
amounts of pastry flour have had no problem rising to normal
respectable levels.
One advantage of high amounts of gluten is the concept of
"tolerance". Tolerance means ability to withstand abuse - abuse like
overkneading, overfermenting, overanything. High gluten flours have
higher tolerance. This means that you have to be slightly more
skillful in using low gluten flours. I would recommend using a yeast
dough rather than a sourdough as a starting point if you are going to
try to make buns with large amounts of pastry flour. The reason is
you have to be very careful not to overferment this sort of dough and
it probably easiest to make a straight dough. I have used sourdough
and got breads as soft as a kiss.
-Roland
------------------------------
Subject: 16. How should I feed my starter for best results?
Continuous culture of the sourdough starter vs the stop start
approach of a home baker is really the big difference between a home
baker and a commercial operation and most home bakers do nothing to
compensate.
The continuous approach in a bakery is exemplified by the starter
culture being doubled every 6-8 hours 365 days of the year (almost).
The home bakers approach is to store the culture and use it
intermittently and so it is worth examining what exactly happens
during this storage process.
The notion of the yeast sporulating on storage etc. is virtually
guaranteed to be wrong for almost all starters. No wild strain of
yeast can sporulate as is frequently stated in books on sourdough,
the FAQ etc. wild yeast most commonly are aneuploid or polyploid and
thus they either do not sporulate or spores have very low viability.
Also no spore would germinate in the 8-12 hour proof given to it in a
bread making regimen. Both the lactobacilli and yeast are simply
dormant in a stored culture and a certain fraction is continuously
dying as elaborated below.
Both the yeast and lactobacilli are inhibited by the acid produced.
As you store a culture the organisms die - lactobacilli at acid pH
die at the rate of 90% a week when stored at room temperature. At
cooler temperatures the rate is slower (4 weeks needed at 4 degrees
for 90% mortality). Because the starting culture usually has a large
number of organisms (in the order of 10E7 - 10E9
(10000000-1000000000) per gram of dough in an active culture with the
lactobacilli being higher than the yeast) this very high death rate
is not immediately perceived - the culture is progressively
enfeebled. At neutral pH the death rate is slower (incidentally this
is the logic why you feed and proof your starter for a very short
time before you return it to the fridge - the proteins in flour
neutralize some of the acid improving survivability and all the
nutrients are not depleted so the culture can grown at a slow rate in
the fridge).
If you do not use a culture continuously but store a culture in the
refrigerator over time only 10%, 1% or less of the culture will be
alive depending on how frequently you use it, what the acidity of the
culture was when you stored it etc. Simply, feeding the culture
with a equal volume of flour water does not bring the number of
lactobacilli up to the maximum number possible - a two fold dilution
does not really relieve the acid inhibition adequately, and instead
of 10000000 organisms/gram you may have only 1000000 or less. The
culture is thus never really vibrant - it is simply limping along.
What I do therefore is to do a very large dilution when I pull the
starter out of the fridge say 1/2 to 1 tablespoon to 1/2 cup flour
and a similar amount of water. This dilution relieves the acid
inhibition and allows the culture to actually divide and grow back
towards the maximum possible. 12 hours later I refeed (doubling the
starter) and repeat this until I have the amount of starter I want
built up. I always try and adjust this so that there are at least a
few doublings of the starter before I actually incorporate it into a
dough. I have used starters from Sourdough International exclusively
so cannot comment on the success of this approach with
non-traditional starters (i.e. anything that is fed on something
other than flour and water). This regimen gives a starter with
excellent properties, with respect to souring, leavening etc. This
is slightly more work than most people usually do but you will be
rewarded by an improvement in flavor, dough characteristics, etc.
-Roland
What is good feeding? I believe that there are two important things:
First, don't starve the culture. This means that you should feed the
culture once it shows evidence of strong activity (frothing or rising
depending on the thickness of the starter) and not too long after
that. If you feed too infrequently the cell populations in the
starter will begin to decline due to starvation, etc.
Second, feed the starter by quadrupling (or even quintupling). This
means that you feed the starter three times it's weight each time you
feed it (i.e., if you have 2 oz of starter, feed it 6 oz of new
food). If you don't have a scale you can do the measurements by
volume, but I think weight is better. I also think that it is best
to keep the starter at a relatively thick consistency. Both the
dilution at feeding and the thick consistency are designed to
encourage the presence of certain good lactibacilli. FYI, when one
feeds by such extreme dilution, it is not necessary to maintain a
partiularly large amount. Starting with a tablespoon of old starter
and mixing this with a quarter cup each of flour/water at each
feeding will leave you with a sufficient amount of starter.
-Sam
------------------------------
Subject: 17. Are all starters the same?
No. I think starters are different, a good starter should be
treasured. Fortunately, the very valuable work of Ed Wood makes it
most simple to prove. All you have to do is to try the Russian or
another "fast" starter from Sourdough International vs a slow starter
from them. The behavior of these starters is very very different
with respect to rate of leavening, and ultimate levels of acidity
produced and anybody willing to spend a few $$ can verify this. I
also think that starters are discernibly different with respect to
flavor. In fact the classical San Francisco sourdough does have a
signature flavor that no other sourdough I have tasted resembles (I
do not have the SI San Francisco culture so do not know how their
version of it behaves with respect to the signature flavor).
I am also skeptical of grape based starters, etc. I know Nancy
Silverton and other celebrated bakers advocate this but I can see no
logic in it. Grapes indeed have yeast and lactobacilli on them. The
problem is these particular varieties of yeast and lactobacilli have
never been recovered in any sourdough starter that has been examined
from any place in the world. These organisms are undoubtedly
specific to grapes as certain other lactobacilli are specific to
yogurt. There are hundreds of strains of yeasts and equally large
numbers of lactobacilli. These organisms develop niches where they
thrive. To transplant an organism from one natural environment to
another is not a formula for success. It is like taking a polar bear
and putting it in the desert. There are hundreds of cheeses made
based on very small differences in starter cultures and processing.
These people are undoubtedly celebrated bakers but to them a yeast is
yeast and a yeast on a grape is a "wild yeast" and they have no
understanding of any of the nuances. I do not claim to know what
exactly is resident in their starters and whether any organisms they
introduce from the grape actually survive and are viable over time
(years as opposed to weeks).
-Roland
------------------------------
Subject: 18. What about Nancy Silverton's latest book?
or 'Stalking the Wild Yeast'
Ringo is, I think, a fine drummer, my household plumbing is a
masterpiece, and all those ice-skaters on TV twirl great. The less
you know about some craft, the less critical you are about its
practice.
Of course, the more you know, the more judgmental you are. I've been
working at sourdough bread baking for a decade; and it has taken me
that long to fight through the misleading sourdough lore. Separating
useful techniques from superstitious ritual has been tough. Standard
bread books are either full of falsehoods ('Beard on Bread' is a
particularly bad example) or misleading and hazy.
So I finally get it right, right enough to be able to teach others,
and what happens? Nancy Silverton publishes 'Breads from the La Brea
Bakery', (Villard, 260 pages, $30), a book that really gets it right,
is clearly written and has an abundance of clever recipes that I
wouldn't have come up with in another 10 years.
Her sourdough creations cover an enormous range: Country White,
Challah, Walnut Bread, Olive Bread, Chocolate-Sour Cherry, Pretzels,
Raisin Brioche, Focaccia, Normandy Rye, Izzy's New York Rye,
Whole-Wheat Boule, Potato-Dill and on and on. This is not just a
great book on sourdough, it is the only book -- an artisanal well of
information and guidance in the craft of great bread baking. When
much store-bought bread is factory whipped wheat candy, when bread
machines are a commodity item, when real bakers are only just
beginning to make a comeback in some urban areas (and even in
Carrboro), it is solace to possess such a valuable 'vade mecum'.
It is sad though that we need such a book. In a well-ordered world,
good bread is no further away than the nearest baker. Only in recent
years have we in Triangle had good bread available at all. Even in
Paris, where bread and pastry is traditionally left to the
professional, a glossy magazine recently lamented the decline of
decent bread and the rise, so to speak, of factory breads sold in
"bakeries"; more astoundingly, it heretically offered instruction on
how to make good bread in the Parisian home.
Although Silverton's directions are clear and superbly organized, the
multi-step, 2-3 day procedures may at first look overwhelming. (See
page 58 for Silverton's hints on time-efficient ways to make bread.)
After a few practice loaves things will get simpler, and you be
rewarded with great bread. Leavened bread is a simple food that has
been around since at least Egyptian times, and its basics are simple.
That's what makes the achievement of great bread such a fascinating
exercise. Flour, water, salt, beasts (bacilli+yeast) and time are
bread's basic ingredients.
Salt is crucial for both taste and texture. Good quality sea salt is
a nice luxury. High quality flour makes a surprising difference. For
basic bread baking (sourdough or otherwise), a good all-purpose,
unbleached, unadulterated flour is called for. In the Triangle area,
the most easily available high-quality flours are King Arthur
(Hannaford's has it at a reasonable price) and Lindley Mills flour, a
local product carried by both Wellspring and Weaver Street.
Beasts. I say beasts because the defining characteristic of a
sourdough bread is that its leavening is a symbiotic culture of
lactobacilli and wild yeast. "Wild yeast bread" might be a better
name, since "sourdough" has led some to think that the sourer the
better; like those who rank peppers or Indian restaurants by how hot
they are. Bread made from a flour, water and commercial yeast slurry,
let to mature for two hours to a day, is not sourdough. That
technique and its variants is called in France 'poolish', in Italy
'biga', and, in American, 'the sponge method'. It is a very very good
way to make bread. It is not sourdough.
Sourdough cultures contain wild yeasts and certain friendly, i.e.,
symbiotic, lactobacilli. The symbiosis is manifold and complicated:
the bacilli produce lactic acid (a 3.5-4.2 pH environment) that its
companion yeast can thrive in, but in which commercial yeast dies;
produce antibiotic agents that are hostile to other organisms; and
metabolize maltose, which wild yeast cannot. The biochemistry is
quite complicated and a far cry from the oversimplified picture of
yeast as a mere belcher of gases. If that's all yeast, or sourdough
cultures did, then there would be a lot more good bread around than
there is!
It is possible to make your own sourdough culture. The underlying
idea is to start with flour and water and, one way or another, let it
sit until a stable culture develops and then feed it into health. The
Silverton book has good, though intimidatingly long, instructions. It
is much simpler and surer to buy a culture from a reputable source;
it is fortunate that there is one. An obsessive guy named Ed Wood
travelled the world collecting old sourdough cultures from
multi-generational bakeries and worked out a way of drying them for
resuscitation. Sourdoughs International (PO Box 670, Cascade, Idaho
83611, (208)382-4828, fax: (208)382-3129])carries cultures from
France, Austria, Bahrain, Russia, San Francisco, Egypt, Saudi Arabia
and Yukon.
SIDEBAR
The basic bread process
Preparation, Mixing, Kneading, Fermentation part one (first rise),
Fermentation part 2 (proofing), Baking, Letting Cool.
The above sequence is, of course, a standard bread making sequence.
The sourdough part is buried in "Preparation". Sourdough starters are
built up in stages. For home baking, where the culture may go a week
or two between uses, this is particularly important. (In traditional
bakeries the 'chef', a lump of dough from the day's bake, starts the
next day's starter.).
The stored 'chef' is taken out of the refrigerator and coaxed back
into life with a series of additions of water and flour, roughly
doubling the amount each time. The staged feeding keeps the increase
in yeast and bacilli in correct proportion. Then the dough is made
from a portion of now vigorous starter.
One item that people used to commercial yeast might overlook is
temperature control. The starter and dough are best at under 80
degrees F. Your flour will be at room temperature and kneading will
add about 10 degrees. There is also about twice as much flour as
water, so your cold (dechlorinated) tap water will almost never be
too cold! And in the summer, you will need ice cubes.
Kneading develops the gluten (gluten is a protein in the endosperm of
wheat which, given the right conditions, forms itself into long
elastic strands that give bread its cellular structure -- the
"pockets" that hold the gases that give baking bread its loft) and
introduces the necessary oxygen. After rising in baskets, free-form
loaves are turned onto peels and slid onto hot stones in the oven.
All breads need to rest, uncut, after coming out of the oven. There
is still stuff happening in there.
A well made sourdough will keep from 4 days to a week on the counter,
wrapped in a towel or in a paper bag. Refrigerator temperatures
hasten staling, and plastic promotes mold and destroys crust.
-David
------------------------------
Subject: 19. How do I get that great crust?
It is difficult to reproduce the effects of a commercial hearth oven
at home. The properties of a good oven include thick baking stones on
the bottom preferably heated with gas fire for more even heat
distribution than electric coils. The oven should have heating
elements at the top of the oven and controls for setting the heat
intensity in all areas of the oven.
The most important difference between baking bread in a commercial
hearth oven and at home, is that the commercial oven has steam tubes
which deliver large amounts of steam at a reasonable pressure. Steam
gelatinizes the starch and protein on the exterior of the loaves
without forming a hard shell. After the steam is removed, the
gelatinized layer dries out forming a thick crunchy crust. With no
steam, it is more difficult to keep the exterior of the bread from
forming a paper thin shell.
Another important difference is that the commercial deck oven is not
very tall from top to bottom which makes the heat more intense than
in a home oven. The thickness of the baking stones also acts as a
heat sink to deliver maximum heat to the bread before the crust
begins to form resulting in better volume. In a home oven, a thin
layer of steam surrounds the bread and prevents efficient transfer of
heat to the bread. Convection ovens work better.
A few things can be done at home to better simulate a true deck oven.
Get a good thick baking stone and of course put it in the oven long
before you intend to put bread on it. Put the stone as close to the
top of the oven as you can still leaving room for the bread to rise.
That will give more intense heat. To simulate quality steam, spray
the bread well with water just before baking. I use another strange
gadget that works very well. I take aluminum muffin tins and poke
tiny holes in the bottom of each well. I fill the tins with boiling
water and place them on the bottom rung of the oven about a minute
before putting the bread in to develop initial steam. The water will
drip onto the bottom of the oven and create steam. Remove the tins
after the first 5-10 minutes or the bread will develop an undesirable
crust. Also, I heat my oven about 50 F higher than i need because
the water evaporation cools the oven. Depending on the oven this
method works pretty well.
-Troy
------------------------------
Subject: 20. How much starter do I need to keep?
I think the important point in the Silverton procedure is to
frequently feed the starter so that it as active as humanly possible.
I think she committed a major screw up by stressing the volumes so
much. Thus it would be perfectly OK to start with 1/2 a teaspoon of
starter and add 1/2 teaspoon water and flour and on the next feeding
double this to one teaspoon, then two teaspoons, 1/4 cup, 1/2 cup etc
until you have the amount of starter that you need for your recipe
and a little extra to store. The doubling procedure is standard
practice in most sourdough recipes but there is no law saying you
have to double. In fact, some German recipes start with a massive
dilution (one in 100) for the first feeding and then use the normal
doubling until the required amount of starter is built up.
A single teaspoon of active starter (or starter stored for a few
weeks at most in the fridge) will have tens of millions of
yeast/lactobacilli. It is thus not difficult to rebuild the starter
from seemingly vanishingly small amounts. A thick head of bubbles
will tell you that you starter is chugging along. Of course this
assumes you have a good starter to begin with - if you do not have a
decent starter then the frequent feeding regimen recommended by
Silverton will rapidly lead to death of your starter(?) because there
simply were not enough organisms to double at the same rate at which
you feed them.
The important point if you start with small volumes is that the
starter can dry out relatively easily - you have only 1/2 teaspoon or
one teaspoon of water to evaporate in the early steps. Thus you
should take steps to ensure that the starter does not dry out - make
it a bit more wet than normal, for the first few feedings cover it
with a wet towel or place it in a glass which in turn is placed in a
rubbermaid container filled with a little water. In the cold weather
I use small coolers that I fill with water at the right temperature
(85F) and then float my starter on rubbermaid boats in there - this
serves as an incubator and also keeps it relatively humid.
I am astounded that a celebrated chef like Silverton could suggest a
recipe that would end up with 7 pounds of starter that you have no
use for! This convinces me that all cook book authors seldom
actually test their recipes or check for appropriateness for their
audience - Silverton's recipe would be fine for a bakery but
ridiculous for the average Joe or Jane that the book was written for.
-Roland
------------------------------
Subject: 21. Sourdough Science 101 or How are the sourness and
leavening of starters related?
Don't let the subject scare you off. My kids tease me that since I
left teaching (biology among other subjects), I have to find other
people to listen to me. They are the usual targets. I'll try to be
gentle - and practical.
There have been several posts over the last little while asking the
same question in different ways - how are the sourness and leavening
of starters related? Some starters seem too sour, or not sour
enough, or have lost their sourness, or are sluggish or too active
(not a problem for most) and folks want to know how to manipulate
this. It also has been pointed out that lactobacilli are anaerobes,
but this needs expansion. Here are some thoughts on this.
I am a homebrewer, and have read a good bit about yeast growth.
Baking and brewing yeast are just different strains of the same
species, but wild yeasts are different species, and some are even
different genera, so this may not apply to all, but I suspect it does.
Cultured yeast needs oxygen to reproduce, so once it has depleted the
oxygen in a starter/sponge/dough, it has pretty much reached the
population it's going to have. After this, it shifts its metabolism
to anaerobic. Assuming that wild yeast are much the same, this
means that letting a starter or sponge sit longer is not going to
result in much more yeast, and therefore will not increase its
leavening power. It will become more sour (see below).
Lactobacilli are facultative anaerobes (as opposed to obligatory
anaerobes), so they will continue to metabolize and reproduce *either
with or without oxygen*. However, they only produce lactic acid once
the oxygen is depleted, resulting in a more sour starter/sponge/dough
the longer you let it sit. I don't think you need to worry about
excluding air - the surface above the sponge or whatever is full of
CO2 from the yeast, so very little oxygen is going to diffuse into
the sponge, especially if you have it covered, and this will keep it
from drying out, too. Of course, during this time, the gluten will
deteriorate the longer you let it sit.
What does this all mean? If you want a maximally active culture,
whip all the air you can into it each time you build it. I add the
water first and whip this thin batter to a froth with an electric
mixer, then mix in the flour. This results in maximum yeast
reproduction. Then, as soon as it has used up all this oxygen, I
build it again. Of course, it's hard to tell just when this is, but
I generally let a sponge go until it just begins to fall. If you
want a more sour bread, let either the starter/sponge/dough go
longer. I find that with high protein flour such as bread or hard
whole wheat, the dough can withstand two full rises before shaping
into loaves, resulting in more flavor (not just more sourness, but
that, too).
I hope this little science lesson has practical benefits to your
bread baking. If anyone knows more details about how wild yeasts and
lactobacilli interact, I'd welcome hearing it, especially if I'm
wrong. I suspect the symbiosis of some cultures may change things,
but this works with my Poilane (originally) starter.
-Jeff
Subject: 22. What is the Microbiology of San Francisco Sourdough?
Several studies have been conducted on the natural microbiological
flora of sourdoughs from around the world. In terms of understanding
the basis of the symbiosis between yeast and lactobacilli the most
successful studies have been by Sugihara and colleagues. Despite the
existence of several varieties of yeast and lactobacilli they showed
that the dominant yeast was a non spore forming variety of
Saccharomyces exigus called Torulopsis holmii and now reclassified as
Candida milleri sp. nov. The dominant lactobacillus was a new
species christened Lactobacillus sanfrancisco sp. nov.
Yeast and bacteria occur in a ratio of 1:100. The unique symbiosis
is explained thus: Though most strains of yeast can metabolise the
sugar maltose Candida milleri cannot. Dough abounds in maltose which
is a released from "damaged starch" through the action of amylase
enzymes. Thus maltose is freely available to the lactobacilli which
have an absolute requirement for this sugar and they cannot utilise
other sugars present in dough. The yeast can utilise all other
sugars present in dough thus the two critters do not compete for a
carbon source. In addition, the lactobacilli have an enzyme maltose
phosphorylase which while assimilating maltose releases glucose into
the media to give the yeast a small boost.
The lactobacilli also secrete an antibiotic cycloheximide which
"sterilises" the dough since it kills many organisms but of course
Candida milleri is resistant to cycloheximide.
Lastly, Candida milleri is moderately tolerant to the acetic acid
which the lactobacilli produce. I should also note that the
nutritional requirements of the lactobacilli is complex - they
require a number of amino acids and fatty acids which may be derived
from dead yeast cells.
Spicher in Germany characterised German sour rye. He found the
dominant yeast species were Candida krusei, Saccharomyces cerevisiae,
Pichia saitoi and Candida milleri. The Lactobacilli included L.
brevis, casei, fermenti, pastorianus, bucheneri, delbrueckii,
leichmannii, acidophilus, farciminis, alimentarius, brevis
var.lindneri, fermentum, fructivorans and Pediococcus acidilactici!
(This zoo of organisms present naturally in Rye flour is the reason
why it is so easy to start a good sourdough culture from rye for
example see "manuels starter" in the Laurel's Kitchen bread book.)
Pure culture studies showed that he could reconstitute a starter that
was close to the original with the yeast Candida krusei and
Lactobacillus brevis var. lindneri. The basis of the symbiosis is not
well understood to the best of my knowledge but is probably similar
in principle to the one described above for San Francisco sourdough.
On a final note, I should point out that pure cultures of
Lactobacillus sanfrancisco are grown on defined media, harvested and
freeze dried and supplied to bakeries around the world to make
instant sourdough!
Should there be sufficient interest in this sort of information, I
can post periodic updates on the scientific lore of breadmaking.
-Roland
------------------------------
Subject: 23. What about Ed Wood's latest edition of his book?
Ed Wood's new edition of his authoritative book on sourdough,(World
Sourdoughs From Antiquity, Ed Wood, 1996, ISBN 0-89815-843-5, Ten
Speed Press, $16.95 paperbound, approximately 9" x 7") is an
attractive book, well laid out, with 185 pages and 8 pages of colour
photos. Some of the colour photos could be helpful to the novice in
learning some of the techniques of bread making. Other colour photos
are from the National Geographic project on ancient sourdough and are
interesting for their historical content.
The book opens with Ed's experiences in investigating with others on
a team how man made his first leavened bread in Egypt, a project
supported by the National Geographic. These experiences and
discoveries were the subject of an article in National Geographic in
1995.
Ed continues with an expert and thorough introduction to sourdough
cultures, their care and feeding, theory, and of course, the making
and baking of sourdough bread.
The book has a good index and around 120 pages of a wide variety of
interesting sourdough recipes, roughly one recipe per page, of
standard and exotic breads, together with pancake and waffle recipes.
This makes for a good book to have on hand both for the novice
learning and the experienced sourdough hand looking for something
different.
There is also a chapter on baking sourdough in bread machines.
However, I agree with Ed that making sourdough in bread machines
involves more art than science. No bread machine on the market that I
know of is really designed for sourdough.
Ed's company, Sourdoughs International, which sells sourdough
cultures, is on the web, and contact information is at
-Darrell
------------------------------
Subject: 24. How can I start a starter from scratch?
I'm puzzled why starting a starter presents a problem to many people.
It really is an extremely simple procedure. I often forget to hold
back some starter from a dough, so I wind up baking the whole lot and
I'm left with no starter to continue, and I have to regenerate from
scratch again. This is an inconvenience, not a disaster! Perhaps I'm
a little careless here, partly because it's so easy to do. In the
hope that it might be helpful to others, here are my thoughts on the
matter:
- Firstly, forget everything you ever heard about catching
yeasts "from the air." Yes, there _are_ yeasts - and lactobacilli -
in the air, but from a practical point of view it is important to
note that there are far more of them already present in flour! In a
cup of flour we're talking millions of them. So the good news is that
you already have the yeasts and bacteria you need, right off the
supermarket shelf, the bad news is that you also have mold spores and
other bacteria which aren't so desirable. Fortunately, given the
right conditions the yeasts and lactobacilli quickly dominate and the
starter becomes too acidic for the other organisms to survive. The
microorganisms are not destroyed (though they are probably
diminished) by bleaching so can happily get a starter going from
normal store flour. However, since they are more plentiful on the
surface of the grain, a wholemeal flour is the easiest (quickest) to
get going.
- Remember that the sourdough microflora require food, moisture
and the correct temperature. You provide food from flour. Rye flour,
because it contains more sugars than wheat, provides more quickly
available food, so for this reason it is easier (i.e. quicker) to get
a sour going. Also, whole grain flour contains more proteolytic
enzyme and amylase (which exist in higher quantities just under the
surface of the grain), so again the food source is richer and the
sour is quicker to get going. The most important point to remember is
to feed regularly. For a beginning starter you need to feed every 24
hours. At the first feed, you probably will not notice much or any
activity, except perhaps a slightly winey aroma (especially if you
use rye). Never mind: feed anyhow. I suspect this is where most
people go wrong - figuring that leaving it a few more days will get
it going! In reality, the yeasts are running out of readily available
food so they are less active, while the molds and other 'off'
bacteria continue to multiply, so you wind up with a slimy goo. By
the second or third feed the starter will be bubbling nicely. By the
fourth or fifth feed it will be adequate to bake with, but it will
continue to develop for a few more days.
- Temperature should be 70-80F ( 20 - 25C ). You could go warmer
than this, but you would then need to feed more often; also, the
nature of your sour would be different, less desirable for a good
loaf.
- Moisture comes from water which you add with the flour. I use
50/50 by weight, which by volume is approximately 1/2 cup water per
cup flour. You don't need to be too precise, so volumetric
measurement is fine, and simple. You can use a more liquid starter,
but you will have to feed more often. [I've seen various discussions
about tap vs bottled water, and tap water works just fine. I suppose
if you live somewhere that has outrageously high chlorination it
might be different, but in general if you choose bottled water you do
so for your own health, not the health of the starter!]
To put it all together: Take 1/2 cup flour (preferably whole meal
rye), mix to paste with 1/4 cup water in a 1 cup size container.
Cover and leave for 24 hours at 70 - 80F. Throw away half of the
mixture, and refresh with another 1/2 cup flour and 1/4 cup water,
cover and leave for 24 hours as before. Repeat. By now, the starter
should show bubbles. If using rye, start using regular white flour
after the third or fourth feed. Now you have a starter which you keep
alive indefinitely by regular feeding.
Happy baking.
-Jonathan
From: JJohn90282@aol.com
Date: Thu, 3 Aug 2000
I was just looking at your article about sour starters. Lots of hard to f=
ind
Info. Just one thing I would like to add is the use of organic flours. Go=
ld
Medal has an organic white flour in most of the stores around here, Portl=
and,
Oregon. Try mixing 2 cups of this flour with 2 cups filtered water. This =
time
of year the starter can used in about 8 hours, or less. It's almost
unbelievable.
-Jim
------------------------------
Subject: 25. How do I get holey, sour, moist and long keeping bread?
I get the most moist dough and most irregular holes when I have the
most over mature dough. Unfortunately, this also correlates with
lower loaf volume and more slump. However, if you look at the loaves
pictured in French Specialty and Decorative Breads (or whatever the
title is, I've lent out my copy), you will see that the bread
fermented with old dough is like that - fairly flat round loaves, and
that wonderful texture I seem to get most often when something goes
wrong.
As far as allowing the dough to "proof" (I'd use the term ferment, or
rise) for a few hours before shaping, that is my standard operating
procedure. I usually let it at least double twice (punching down in
between).
So, in general, if I always go to the next stage (starter to sponge
to dough to loaf) when that stage is at maximum volume, I get less
sour bread with more "conventional" texture. The more I let the
stages go, especially the dough stage, the more holey, sour, moist
and long keeping the bread is.
- Jeff
An irregular crumb is achieved with an extensible dough. This is most
easily done using a "weak" flour. French bread flour (type 55) has a
protein level which is extremely low by US standards (9 - 10 % vs
12%+). Using a weaker flour, highish hydration (65%+) and short
mixing time is the surest way to get good irregular crumb, and don't
shape your loaves too tightly. But don't expect enormous holes, as in
ciabatta, unless you to extreme hydration. Of course, the lower
protein flour will have less tolerance than a normal US bread flour,
so be careful not to overproof.
- Jonathan
------------------------------
Subject: 26. Is slashing of loaves aesthetic or functional?
Both.
Historically, French rural ovens were communal, in a sense: they were
originally owned by the lord, and maintained by a fournier, or
ovenmaster, who kept the oven hot but charged for its use. Since the
bread of each household would be mixed with others in the oven, a
distinctive slash was one way to tell the loaves apart. After the
feudal power of other lords (and the Church, which also controlled
many ovens) was broken, the ovens were (and are, in places like
Bugey, in Eastern France) owned by the "commune", the governmental
body of the city or district. The are still used on holidays, and the
bread is still distinctively slashed.
Anyway, bread which is not baked in a pan and which is not proofed in
a 100% humidity environment will almost always burst as it is baked,
and the burst is uncontrolled and messy. The slash controls this,
but is also decorative - it enhances the vitality of the process...
as the burst shows how well the baker matched the rising power of the
leaven to the mechanical properties of the gluten. A nice slash and
shred is a sign of proficiency in baking.
Whole grain breads that do not rise or spring as markedly do not need
to be slashed if they are proofed in a high-humidity environment.
-Dan
Additionally slashing prevents a "flying crust." Flying crust is a
term describing the lifting of the entire upper crust of a loaf
during baking to form one large bubble.
Darrell
------------------------------
Subject: 27. How do lactic bacteria affect sourdough bread?
13 Feb 1997 10:49:32 +0100
Dear Daniel Wing!
Your letter to Prof. Hammes has reached Hohenheim, and Prof. Hammes
has asked me to take care of the communication. I am a Ph.D.
candidate in Hammes' lab working on the physiology of sour dough
lactobacilli.
Please feel welcome to address questions to us concerning sour dough
microbiology and technology! I will mail two recent publications or
our lab concerning the physiology of sour dough lactic acid bacteria
by mail, but as they may take a week or longer to reach you, I will
give a few comments on the questions in your letter:
- yeasts do not produce appreciable amounts of either lactic or
acetic acids, their main metabolites are ethanol and CO2. If
acidification of the dough is desired or required (e.g. if rye flour
is used), lactic acid bacteria or organic acids (most commonly lactic
or citric acids) are added.
- homefermentative lactic acid bacteria do produce solely lactic acid
from maltose or glucose under anaerobic conditions (as they are
prevailing in sour dough fermentations). Thus, doughs acidified with
homofermentative lactic acid bacteria (LAB) contain but little acetic
acid. As homofermentative lactic acid bacteria do not produce CO2,
yeast must be added to ensure leavening of the dough.
- In sour doughs with a tradition of continuous propagation (such as
the San Francisco French Bread Sour Dough process, German rye sour
doughs or sour dough employed in Pannettone production in Italy),
heterofermentative lactobacilli, especially L. sanfrancisco, are
dominating the fermentation. Heterofermentative lactobacilli produce
lactate, ethanol, and CO2 from hexoses (most strains do not ferment
pentoses), HOWEVER, if additional substrates are present that serve
as electron acceptor to balance, acetate is produced instead of
ethanol. I do not know whether or not you are familiar with the
concept of the "redox balance": Degradation of hexoses via the
pentose-phosphate pathway as employed by heterofermentative LAB
results in phosphorylation of ADP to ATP, and in the reduction of NAD
to NADH. As there is no use for NADH, it must be oxidized to NAD
again. In the absence of other substrates, acetyl-Phosphate is
reduced to ethanol, with two NADH becoming oxidized to HAD in the
process. If either fructose, oxygen, citrate or malate are present,
these become reduced to mannitol, H2O, lactic and acetic acid, and
succinate, respectively, and acetyl-P is dephosphorylated to acetate.
(This explanation may not be very straightforward, I hope we did a
better job in the publications I`m about to send you; these also
include a diagram showing the metabolic pathways of L. sanfrancisco).
The consequence for the molar ration of lactate:acetate (fermentation
quotient, FQ) in sour dough fermentations is, that acetate in
produced only if one or more of the above mentioned co-substrated is
present. Oxygen is present only in the beginning of the fermentation,
and the amounts of oxygen are too low to result in significant
amounts of acetic acid, though, in principle, it is possible to
increase the acetate content by aeration of dough. Fructose is
present in sucrose and other glucofructans with higher molecular
weights. Fructose is released from these compounds by cereal or dough
enzymes (many strains of L. sanfrancisco don`t even cleave sucrose)
and consequently reduced to mannitol by L. sanfrancisco. The ration
of mannitol : acetate in sour dough fermentation is approximately
2:1, suggesting that fructose is the most important electron
acceptor. Furthermore, citrate and malate are present in the dough in
amounts less than 10 mmol/kg, these are utilized also.
Thus, the effect of substrates and oxygen on the FQ is nicely
explained by the metabolic characteristics of the dominating
fermentation organisms. Dough yield (=3Dkg dough per 100 kg flour) and
temperature also influence the FQ. Spicher reports that softer doughs
lead to an increased FQ; an increase in temperature results in higher
amounts of lactic acid, while the amount of acetic acid remains more
or less the same, thus, the FQ is increased again. I do not have a
straightforward explanation for these phenomena, but changes in dough
yield and temperature will result in changes in buffering capacities
of the dough, modified activities of cereal and microbial enzymes, as
well as a changed ration of yeasts : lactobacilli counts, all of
which are likely to influence the FQ.
Yours
Michael Ganzle
--
Dear Michael Gaenzele
Thank you for sending one of the most gracious letters I have ever
received in response to any kind of an inquiry. Since I wrote to
Prof. Hammes I have been able to copy a number of articles from
English language publications by Drs. Brummer, Spicher, Vogel, and so
forth. Unfortunately, some of them have been in non-technical
journals and were thus short on details, and even the less technical
ones were not as clearly and idiomatically written as your letter. I
DID have a hard time understanding what was meant by Dough Yield, for
instance, although I had figured it out before I got your letter. I
am still not sure I understand some of the statements those authors
made about the acid content of doughs (such as the units of
measurement), but I have been piecing things together by looking at
all the articles cumulatively. Your letter has clarified a great
deal. I will put stars next to my current questions to make THIS
letter easier to answer. Like this *.
One problem for me was that I did not realize how predominant rye
flours were in German sourdough baking. I know that typical rye
pentose is about 8% and that pentose viscosity is important in
gas-trapping in rye doughs (He and Hoseney, 1991) but I still don't
know how an acidified rye dough behaves differently from a more
neutral one. *Does it affect viscosity somehow? He and Hoseney
studied neutral doughs only.
I also do not understand why Brummer says "Anstellgut" is a
non-translatable term. *What do you think it translates as? *I take
it that this a very ripe starter, very acid, maintained at room
temperature at some infrequent rate of refreshment? *Is it always rye
based? *Always a high-ash flour? *How is it different from the type
of French and American wheat starters that are refreshed 1:1 every
eight hours, or 1:4 every 12 hours? *What is its consistency, pH,
Total Titratable Acid? *My assumption is that my lack of
understanding comes from the German use of sourdough as primarily
acidification, whereas here we look for a little acidification, a
good flavor, and good leavening power.*Do German bakers ever make
wheat breads leavened with higher starter percentages than those
Brummer cites, for example 20% or 30% starter? *Or do they acidify
with very ripe starters and leaven with commercial yeast?
I am curious about the flavor/sensory aspects of the FQ: *When a
bread is fairly sour (SF Sourdough, some rye breads) is the perceived
sourness mostly lactate, mostly acetate, or due to the pH or TTA of
the bread? Calvel brings this subject up, but does not resolve it to
my understanding.
As for your answers to my previous questions, thank you -- I will
look this material over again, and let you know if I have questions.
*Do you mind if I put the text of your letter (with attribution) on
the internet as a posting to the newsgroup Rec.Food.Sourdough? I will
NOT put your address or email address in the posting, unless you want
me to. Please let me know, as I think it might become part of the FAQ
file there (Frequently Asked Questions). I will forward your entire
letter to a very few people in academia here who have been helping
me, so you might hear from one of them.
Dan Wing
--
14 Feb 1997 15:50:30 +0100
Dear Dan Wing!
I do not mind if the answer is posted to the rec.food.sourdough: I've
also been browsing in that newsgroup.
To answer a few of your questions:
I) There is no rye bread without acidification of the dough. Rye
flour does not contain gluten (or a different type of gluten that
does not have the gas-retaining properties), so that the structure of
rye bread relies mainly on gelatinized starch. Rye flour does have a
higher amylase activity than wheat flour, furthermore, the
gelatinization temperature is a few degrees lower than that of wheat
starch. Thus, with the temperature optimum of rye amylase being about
50 - 52C (with substantial activity up to temperatures of 70C) and
starch gelatinization starting at 55C, starch is degraded during the
baking process UNLESS the amylases are inactivated by lowering the pH
below 4.5. The situation is exacerbated if there was wet weather
during the harvest, as germinating rye has higher amylase activities
and the starch granules are damaged, thus facilitating hydrolysis.
II) "Anstellgut" is more or less the same as the continuously
propagated wheat starters of the SF sour dough bread, so no harm is
done if it is translated as "starter sponge" or something like.
German sourdoughs usually are rye based for two reasons: 1) Due to
the climatic conditions in Germany, especially in the northern and
eastern parts that make it difficult to grow wheat, rye flour is just
as important for bread production as wheat flour. 2) As these is no
necessity to acidify wheat flour (though it enhances the flavor),
most bakers do not use sour dough to produce wheat bread. Starter
sponges are not necessarily propagated separately. If the dough is
taken care of according to traditional methods, it is re-inoculated
three times to produce bread dough (reading Bruemmer and Spicher, you
probably have already encountered the "three stage sour dough
method." A part of the bread dough is used to prepare the sour dough
for the next day. This makes 3 - 4 inoculations a day, the ratio of
sour dough to fresh dough being approximately 1:3. One has to make a
point of it: there is no typical sourdough without continuous
propagation! The microflora of these rye starters is actually the
same as for wheat starter in SF or Italy: Lactobacillus sanfrancisco
and Candida milleri or Saccharomyces exiguus. The pH of a ripe sour
dough will be between 3.6 and 4.0 (L. sanfrancisco does not grow
below pH 3.6). The total titrable acidity (TTA) depends on the flour
employed: as the lactobacilli acidify to pH 3.6, flours with high
buffering capacity (amount of acid required to lower the pH), e.g.
whole flours, have a higher TTA than white flours with a low
buffering capacity. Furthermore, if "hard" water with high
concentrations of Me2+ CO3- is used, the TTA will be higher.
3) Acidification vs. leavening: As mentioned above, rye flour or
mixtures of rye and wheat flours containing more than 20% rye must be
acidified in order to get bread. As the propagation of sour dough is
very time consuming if the full leavening capacity of the organism is
to be obtained, quite a few processes have been developed in Germany
that ensure that the dough is acidified (or that the sour dough added
to the bread dough contains enough acid to bring the pH of the bread
dough below ca. 4.5), but no leavened by the sour dough microflora.
Leavening is achieved by bakers yeast. Basically, there are three
possibilities: 1) Dried sourdough with a high TTA (>20) is added to
the bread dough, there are no lactobacilli involved in the
fermentation (sometimes they are present in the dried sour dough
preparation anyway, as in Germany, something called sour dough must
contain viable lactic acid bacteria. The dried dough is sold much
more readily if it can be called sourdough). 2) A sour dough is kept
at room temperature for up to one week. The TTY of that dough is high
enough to use it for baking, but as the organisms are rather stressed
in such an environment, they will not contribute to the leavening of
the dough. Such doughs do not contain lactobacillus sanfrancisco, but
other lactobacilli that are more acid tolerant (the ph of such a
dough reaches 3.4 - 3.6 after one day, and stays there for the four
or five more days that the dough is kept). 3) One stage or two stage
processes with starter sponges. One or two stage processes usually do
not ensure that the lactobacilli in the dough are fully metabolically
active if the bread dough is prepared, thus, the leavening capacity
is rather poor, but enough acid has been produced. As far as I know
(I never made a survey, though), only few bakers make bread with
traditional processes without bakers yeast added to leaven the dough.
Acidification of the bread dough with sour dough is rather common,
and the sensory quality of such bread is quite close to that of bread
made without bakers yeast. Straight processes with bakers yeast and
chemical acidification (citric, lactic, and acetic acid, or mixtures
thereof) are also quite common to produce rye bread.
4) Lactic acid and acetic acid will change taste and flavor of bread
beyond the decrease of pH: the taste buds (sour, bitter, sweet,
salty) are on the tongue, any other aroma is perceived with the nose;
therefore, the aroma compounds must be volatile. Acetic acid is more
volatile than lactic acid, thus, it's impact on the flavor is more
pronounced than that of lactic acid. Spicher says that a ratio of 20
acetate to 80 lactate is optimal. It must also be taken into account,
that the lowering of the pH influences the formation of other aroma
compounds during the baking process. The acetic acid is furthermore
important as growth of spoilage organisms such as molds or rope
causing bacilli (Bacillus subtilis) is inhibited by high acetic acid
concentrations.
I hope that I could answer your questions
With kind regards
Michael Ganzle
------------------------------
Subject: 28. What is hooch? Refrigerator hooch? What do I do with it?
Hooch and refrigerator hooch are the same thing.
When the starter goes quiet (this tends to happen faster in the
refrigerator, whence 'refrigerator hooch') the mixture separates. You
have a layer of flour with miscellaneous yeast and bacteria and a
layer of water with a touch of alcohol (whence 'hooch') and other
fermentation byproducts.
You mix the hooch in with the layer of flour when you feed your
starter otherwise you will change the water:flour ratio of your
starter.
A better way, in my opinion, to restart an old hooch layered starter
is to use a tablespoonful of the old starter to get another flour and
water mixture going as a new starter. You can get a healthier starter
faster that way.
-Darrell
------------------------------
Subject: 29. How can I determine the proportion of flour and water
to use in my starter and dough?
Proportion of water and flour in starter and dough, and why I like
100% starters:
A recent poster related difficulty controlling and predicting the
viscosity of starters. One of the responses referred to the usual
professional baker's practice of measuring by weight, not volume.
This is the so-called "baker's percentage" (or "hydration" or
"absorption ratio"), in which the weight of each of the other
ingredients is compared to the weight of flour used. Thus equal
weights of water and flour make a 100% starter, while a typical dough
made with all-purpose flour is a 60% dough, while one made with all
"bread" flour is typically about 70%, since the extra protein can
trap a greater amount of water. Some European bakers use a variation
of this percentage system, called "dough yield".
Anyway, there is are several advantages to using a 100% starter, with
equal weights of flour and water. One is because it makes it easy to
calculate the amount of water and flour (and salt) that must be added
to the starter to make dough batches of different sizes. For example,
I like to make large loaves that weigh 1500 grams. Forty percent of
that is 600 grams of final starter that I will need when I make my
dough. Forty percent of that amount of starter is 240 grams of
intermediate starter. One-quarter of that is 60 grams, so that is the
amount of my "original" starter I begin with per loaf I will make.
Suppose I want to make about 1500g of dough at 65% baker's
percentage: I divide 1500 by 165 (100% flour, 65% water), then
multiply the result by 65 (for the total weight of water) and by 100
(for the total weight of flour) as well as by ) 0.02 (to determine
the weight of salt needed, which is typically 2%). I am going to need
909 grams of flour, and 590 grams of water, as well as 18 grams of
salt.
Now we see one advantage of using a 100% starter: since I have 600 g
of "final" starter, I have 300 g of flour and 300 g of water, and I
can subtract those amounts easily to give me 609g of flour and 290 g
of additional water, a well as 18 of salt. Adding the starter and
these amounts of flour, water, and salt will make my dough. These
easy calculations are essentially the same for any quantity of dough
you want to end up with on any given day.
The other advantage of a 100% starter is that for MOST starter
cultures a 100% starter will become ripe in 8 hours or less after
each substantial refreshment. That is easy to remember and handle--
thicker starters are often slower, although they last longer in
storage.
Finally, the acid load of a 100% culture is moderate when it is ripe,
so it will make a nicely balanced bread (flavor balance) when
appropriately handled.
-Dan
------------------------------
Subject: 30. How can I ship my starter to someone else?
Take refreshed starter at peak yeast activity, and add flour to make
"noodle dough". Roll it flat so that 2/3 oz. or so fills a postal
envelope. (A postal employee wrote suggesting a cassette mailing box
available cheaply from Radio Shack -- dg) Wrap it in cling plastic
and mail it ordinary first class. It should be so dry as to resemble
slightly damp cardboard.
I assume a white flour starter fed and compounded with same. A week
in the mail will not bother it. It can be stored in the frig for
months in this form.
-Dick
------------------------------
Subject: 31. How do I get that lofty loaf?
Getting the lofty loaf starts way back with kneading and getting the
correct consistency (percent hydration). This is easier to do when
you weigh rather than volume-measure ingredients. Next, your
fermentation stage (after kneading, before dividing and rounding)
should not be excessively long. Sourdoughs do not have to double in
bulk in fermentation, as much of their flavor and microbiological
vigor is carried from the prefermentation stages-- from the sponge or
leaven you have made from your active starter.
The next most critical determinant of a lofty loaf is shaping. Some
people shape the finished loaf just after they have divided the
dough, which works well for plastic doughs, like high percentage rye
flour doughs. But for elastic and extensible doughs, like well
hydrated, well kneaded wheat doughs, it is better to divide, round
the loaves (pre-shape, pre-stretch the dough structure) and let them
rest about 10 minutes on the bench. Then when you finally shape them
(means just that, not just making a big lump) you will get the
necessary gluten tension to provide the lofty loaf you seek.
If you are in doubt, underproofing is better than overproofing, Of
course perfect proofing is best. But any well shaped, well proofed
loaf should be able to take slashing by a very sharp knife-- 'been
doin' it for years.
-Dan
------------------------------
Subject: 32. What is San Francisco Sourdough?
As I understand it, all stable "sourdough" starters are a symbiotic
mixture of yeasts and bacteria, that, through their mutual liking of
the other's by-products, cause the mixture to remain stable over
time, relatively unaffected by other wild yeasts & bacteria that may,
by chance, settle into the mix.
In the case of "San Francisco Sourdough" the protagonists have been
identified as Lactobacillus sanfrancisco (the bacteria) and
Saccharomyces Exiguus (the yeast).
These two players seem to be common in the air in the San Francisco
bay area, and hence, starter started there contains them in
abundance. Their mutual relationship gives bread made therefrom a
singular tang.
In 1995, I toured the bay area stopping at many bakeries to sample
their "sourdough". Parisian was the most bland, though most widely
distributed; Le Bolangerie was the most tangy and "sanfranciscian";
the Village Baker, in Petaluma, was the most interesting. I did not
get to Acme in Oakland, which is deemed by some to be, well, the acme.
I, like others on this list, have attempted to duplicate the taste I
had tasted in SF, here in eastern Mass., with little success. I have
tried inoculating commercial "San Francisco Sourdough" starter with
Lactobacillus sanfrancisco, obtained from a baking industry contact,
to little avail. The resulting loaf _was_ "sanfranciscian" but the
starter did not retain that quality for the next batch. I believe
both Lac. SF. and Sacc. Ex. must be in the air & the flour, or the
symbiosis will not survive in the starter.
Troy Boutte, of this list, wrote in 1995:
"Lactobacillus san francisco, when fermented by itself from a pure
culture, has an odor of canned corn early in the fermentation. After
about 17-20 hours of fermentation under good conditions, the pH of
the ferment will drop to about 3.6 - 3.8. At that time the odor will
have changed to a very complex and unique odor which of course makes
it impossible to compare it to anything else.
Most people say it smells like sweaty sneakers or old socks, but not
in an unpleasant way. ... The odor comes from 40-50 small volatile
compounds that have been identified in these ferments. Besides
lactic acid, the most abundant compounds are acetic acid (vinegar),
ethyl acetate (cross between vinegar and alcohol), and ethanol.
Other compounds are esters of short chain fatty acids that give goat
cheese and butter their respective odors and flavors.
I've found that the odor of this ferment bears little relationship
with the flavor of the bread produced. Baking seems to mellow out
the flavor, leaving what many people consider to be an excellent
flavor to the bread."
-George
------------------------------
Subject: 33. What temperature should my starter be for best results?
Typical sourdough actually may contain three different types of microorga=
nisms.
We all know about yeast and those bacilli that produce lactic acid.
There may also be different bacilli in your dough, namely ones that
produce ordinary vinegar or acetic acid.
(There is also the possibility that there are still different
microorganisms in there, but you usually don't want that to happen.
Worst example are the bacilli that produce a kind of acid that also
makes very old butter stink.)
Each microorganism has its own favorite temperature.
The bacilli that produce lactic acid like rather high temperatures of
37-40 degrees C or 99-104 degrees F.
The bacilli that produce vinegar are active only if there is yeast
that has already produced alcohol. (Yeast always does that, it never
produces gas without producing alcohol, so the word "alcohol" should
not alarm anyone.) Those bacilli like rather low temperatures, 20-25
degrees C or 68-77 degrees F.
Personally, I want lactic acid and not vinegar in my sourdough. You
can tell the two apart by the fact that lactic acid tastes sour, but
does not smell sour. Also, vinegar escapes as a gas during the baking
process as well as during storage of the bread, whereas lactic acid
stays.
Yeast will grow (multiply) fastest at 24-27 degrees C or 75-81
degrees F. (Yeast also needs oxygen to multiply.) Yeast will produce
gas fastest at a somewhat higher temperature, namely 30-32 degrees C
or 86-90 degrees F.
So, my own conclusion from all this is: the temperature which you use
to maintain the starter will, in the long run, affect the kind of
microorganisms you have in there.
If you want lots of lactobacilli, use higher temperatures when
refreshing the starter. If you refresh your starter at comparatively
low temperatures, you may get a dough that smells sour and contains a
lot of vinegar, but the resulting bread isn't all that sour.
-Andreas
------------------------------
Subject: 34. Can I freeze or dry my starter?
With regard to freezing, I have done this for years: I put a cup of
starter in the freezer and in six months or so thaw and feed it then
refreeze. It has always worked so I have not understood the
frequently expressed concern about freezing. I think people should
always freeze part of their starter for safety's sake. Of course,
they can always get some more from me by sending me a SASE.
(Ed. note -- be sure your starter can handle freezing like Carl's
before you rely on this method of preservation.See
"http://www.nyx.net/~dgreenw/sourdoughfaqs.html#sources" if you would
like to obtain Carl's starter)
I only dry the starter when I know I am running out, which may be
every week or two. I prepare a batch of starter for distribution by
combining one tablespoon of stock starter, 1/3 cup water, and enough
flour to get waffle batter consistency. I activate this mixture at
room temperature (about 70 degrees F.) until I can see small bubbles
in the body of the starter ( not frothing or hooch formation.) (The
stock starter culture is kept in the refrigerator. It is fed and
activated every two weeks or so, i.e. whenever I think about it or
need to use it.)
I pour the activated mixture into three 10-inch diameter plastic
picnic dishes to a depth of 1/8 to 1/4 inch. It dries for several
days at room temperature. The dry starter does not stick to the
dishes. It dries on the top first, but the bottom is then exposed
with a knife. Otherwise drying would be too slow. One could use
regular ceramic or metal dishes if you put a layer of plastic
sheeting over the dishes so the wet starter didn't stick to the dish.
Waxed paper should work as well. When it is dry and brittle I break
it up and grind it in a blender. It seems to work OK. I wonder if
other people always activate their starters before they dry them.
I leave the dried starter in the freezer for several weeks, long
enough to fill the requests that I get in the mail. Never had a
report of my starter failing to reactivate. (I test each batch before
it goes out in the mail by reactivating a portion of it to make sure
it is OK.) Well, that is just the way I do it. Cooking is not a
mathematical science. When I learned to cook some seventy years ago
in a cattle trail chuck wagon and ranch house there were no
quantities or temperatures in recipes - just did it feel good or look
right, or taste good, and did the cowhands like it, was all there
was. This can be checked with many of the recipes from that time. We
used ones printed in the 1800s.
-Carl
------------------------------
Subject: 35. What happens if I start my starter with commercial yeast?
Many people believe that a starter started with commercial yeast will
eventually be "taken over" by wild yeast. This is a good thing, and
the quality/predictability of the resultant bread should improve as
this happens, since commercial yeast isn't really designed to be used
that way. Until that process is completed, the starter is in a state
of transition toward a desired end-state where wild yeast and
bacteria maintain a balanced, stable, symbiotic relationship. It
follows that an evolving starter will produce breads with differing
characteristics as the nature of the starter changes. Only a stable
starter will produce consistent results.
It can actually take quite a while for a starter (even one that began
without commercial yeast) to reach a good balance of microbiological
life. This is one of the reasons why many bakers use cultures from
long-established starters (why go through all the time and trouble to
nurse your starter to a balanced state when there are lots of
already-balanced starter cultures out there with proven
characteristics?).
-Sam
There was an experiment done by a Dutch group: baker's yeast didn't
survive more than two refreshments of a sourdough culture. I think
that it's the acetate that kills the yeast as it is less acetate
tolerant than sourdough yeasts.
-Michael
------------------------------
Subject: 36. What do all these baker's terms like poolish, biga, chef, m=
ean?
Poolish-- Is French for a mixture of flour and water and a little
bakers yeast. The ratio of flour to water is 50 - 50 by weight.
Biga-- Italian for the same thing except the biga can be like a
poolish or very firm.
The above are both yeasted.
Chef-- a dough-like starter that is either an unrefreshed levain or a
piece of dough saved from the previous day's bake.
Levain-- a chef that has been refreshed with flour and water.
Biga Natural-- same as levain, but in Italian.
Mother-- this is a batter like starter of flour and water that is unrefre=
shed
Sour-- a mother that has been refreshed with flour and water.
Mother =3D chef - it only depends on the consistency (chef dough-like,
mother batter-like). Most people here in the US call this just plain
starter.
Sour =3D levain - again it depends on the consistency of the starter.
(Sour batter-like, levain dough-like) - The difference between these
terms and the ones above is that they represent the term that
indicates that the starter is activated.
Chef, levain, biga natural, mother, and sour contain only natural
yeast cultures.
All of the above are often referred to as either starters or sponges.
-Matt
--
Chef is a piece of dough held over to start the process of making
future doughs. It preserves the makeup of the leaven culture used at
any particular bakery. In the old days, use of la stiff (dough
consistency) chef was important because there was no refrigeration.
Stiff consistency =3D slow fermentation compared to thin consistency.
Most bakeries now use more liquid leavens, and store them in the
refrigerator when necessary.
Levain is the French term for a sponge or soft dough that is being
used to propagate a sourdough culture.
Sponge is a thinner (more watery than dough) dough stage that allows
for vigorous fermentation. It may incorporate all the water that will
eventually be in the dough, or some portion in it. When baking with
commercial yeast, a sponge allows a baker to only use one-quarter the
amount of yeast, which reduces yeast's off-flavor. When baking with
"natural ferments"-- sourdough cultures-- the culture is often
propagated in a series of sponges which are then called levains
(French), barms, leavens, starters and a few other names. I
personally have come to use the term "starter leaven" for a new
leaven culture that is being developed, the term "storage leaven" for
one that I hold over in the refrigerator, and the term "intermediate
leaven" for one that I use as a stage of propagation between the
storage leaven and the dough itself. In France and Germany there are
specific names for the three levains that make up (with the chef) the
twenty four hour cycle of the traditional small bakery.
proof -- This term is best used to describe the time of rising of the
loaves AFTER they have been shaped, although it is also used to
describe the time of rising before they are shaped. Many professional
bakers use the term "fermentation stage" for that time after mixing
and before shaping
Yeasts:commercial -- This refers to yeasts that are propagated in
nearly pure culture and (these days) usually sold in dried form. In
the past 10 years manufacturers have moved beyond "natural selection"
and the refinement of mutations-- they are now using genetic
engineering. Yeast are available with high resistance to freezing,
for example. Though most yeast packets contain some bacteria, there
are not enough to produce the acid and the volatile organic compounds
that give sourdough bread its flavor. Also, most people use so much
commercial yeast that the bread tastes more of it than of wheat. The
amount used can be reduced when bread is made with the sponge process
Yeasts:sourdough -- Bread made with natural leavens: a mixed culture
of yeast and bacterial strains recovered from environmental surfaces
(grain, grapes, etc.) and then propagated continuously by bakers.
-Dan
------------------------------
Subject: 37. What is the relationship between temperature and
sourdough activity?
Recent information indicates that the time-temperature relationship
is steeper than was proposed, and not quite so log-linear as had been
assumed.
Through the range 40 to 75 degrees, rates may double approximately
for each 7 degrees F., rather than for each 18 degrees F. as I had
assumed. That is based on information sent to me by Michael Gaenzle,
who, with colleagues, has studied growth rates of sourdough yeasts
and bacteria, and on (my) assumption that leavening activity and
yeast growth are mutually proportional.
Further, Michael Gaenzle (G=E4nzle) has shown that sourdough yeast
growth (for the SF sourdough yeast organism) is severely retarded by
temperatures much above 85 degrees F. and that culturing above that
temperature can deplete the yeast, leaving the lactobacillis
predominant.
Michael's study was published last July in _Applied and Environmental
Microbiology_, but I have not seen it. I have appended the
information that I have (an email received last June 28) in case some
one would like to help me speculate on how a time-temperature table
might be presented.
There is probably a simple answer about how to adjust "proofing"
times for various temperatures, but I have come to understand that I
am not exactly sure what it is just now.
Thanks to Michael for his contributions to sourdough science, and for
his interest in our discussion group.
- Dick Adams
Dear Dick Adams
Please find attached the growth rates of L. sanfranciscensis and C.
milleri as function of temperature. Growth rate is ln2/generation
time, i.e. a growth rate of 0.7 is a generation (doubling time) of
about 1 h.
The generation times measured in laboratory media are different from
that in rye / wheat / white wheat dough, however, if the generation
time at 20 C is 1/2 of that at 30 C in my medium, the organism will
also grow 1/2 as fast at 20 C compared to 30 C in dough (we checked).
So, it's not the absolute numbers that matter, but the ratio of
growth rate to growth rate at optimum temperature.
Temp L. sf I L. sf II Yeast (C. milleri)
2 0.019 0.016 0.004
4 0.026 0.022 0.008
6 0.035 0.031 0.013
8 0.047 0.043 0.021
10 0.063 0.060 0.033
12 0.084 0.08 0.052
14 0.11 0.11 0.078
16 0.14 0.15 0.011
18 0.19 0.20 0.16
20 0.24 0.26 0.23
22 0.30 0.29 0.30
24 0.37 0.37 0.37
26 0.45 0.46 0.42
28 0.49 0.55 0.42
30 0.61 0.64 0.35
32 0.66 0.70 0.20
34 0.66 0.70 0.05
36 0.58 0.54 0.00
38 0.39 0.31
40 0.1 0.055
41 0.00 0.00
The curves were generated by fitting the following curve to experimental =
data:
growth rate =3D a (x^b)(e^cx)
for lactobacilli, x is (41-temperature), all temperatures are in deg.
centigrade
for the yeast, x is (36-temperature), all temperatures are in deg. centig=
rade
A, b and c were calculated as follows for the three organisms:
L. sf I L. sf II Yeast
a 0.1267 0.0682 0.0124
b 1.5404 1.9782 2.9810
c -0.1931 -0.2233 -0.3355
If I didn't make a typing error this equation should generate the
curve described above. The curve does not give the best approximation
at temperatures below 10C, though.
Transfer of the curves from our strains to your starter may change
things a bit, but nevertheless I think that it may serve as guideline
for many sourdough starters.
Let me know if you think it works (or not).
- Michael
------------------------------
Subject: 38. Is there a glossary of rec.food.sourdough terms?
ATCC: American Type Culture Collection (www.atcc.org), a source for
pure strains of micro-organisms, including those that predominate in
natural leavens.
absorption: The ability of a flour to take up and hold water.
Generally higher for high-gluten flours and those with relatively
high damaged-starch levels.
acid: A solution containing free hydrogen ions, or a substance that
will release them when dissolved in water.
acid pH: Since pH is a measure of the acid/base state of a solution,
"acid pH" indicates that the solution in question is acid, and a has
a pH of less than 7 on a scale of 14.
acid tolerance: The ability of a micro-organism to grow in acid condition=
s.
active starter: A leaven that has recently reached its equilibrium
yeast and bacterial population. If thick, it will be spongy,
tenacious, and gassy. If thin, it will be frothy and bubbly.
amylases: Enzymes present in grain but also supplemented by millers,
capable of breaking damaged starch down to sugars and dextrins. These
sugars then power fermentation and contribute to carmelization and
the Maillard reactions (browning of the crust).
Anfrischsauer: The first stage (first expansion) of the traditional
German baking sequence, made from Anstellgut, water, and flour.
Anstellgut: The inoculant to the first stage in the three-stage
sequence of expansion of a leaven culture in the traditional German
bakery. It is a portion of the ripe sourdough from the previous day.
ash content: The mineral content of flour.
autolyse, autolysis: A rest during kneading (5-20 minutes) to allow
the dough to continue hydrating and the developing gluten to relax
before kneading is resumed and the gluten is taken to full
development. Usually done when dough is being machine-mixed.(French,
English)
bacteria: Single celled organisms with no defined chromosomes (yeast
don't have defined chromosomes either). Neither plant nor animal.
Usually smaller than yeasts. Some can ferment, but usually don't make
CO2 in the same amounts as yeast under typical conditions-- they make
organic acids instead.
bake: Heat to an internal temperature of at least 195 degrees
Fahrenheit in a dry environment. For hearth loaves (not in a pan) the
environment should be humid initially, then dry.
baker's yeast: Strains of brewer's yeast selected and commercially
produced for raising dough.
baking yeast: Same.
batter: A thin mixture containing flour and water, in the range of
100% hydration or higher.
barm: A leaven or starter, sometimes implying one made from brewing
sediment. (English)
beer yeast: Brewer's yeast selected for making beer.
biga: Originally the same as starter or leaven (natural leaven) but
now used to refer to a sponge raised with commercial yeast. (Italian)
bottom-fermenting yeast: Brewer's yeast (lager yeast, Saccharomyces
uvarum) which forms its fermenting mass in the bottom of a vessel of
liquid.
chef: A piece of a previous batch of dough kept over to inoculate a
new flour/water mixture, which will then become a leaven, starter,
sponge (synonyms).
commercial yeast: Factory-produced yeast. The species is the same as
brewer's yeast, but the characteristics may be very different. This
term includes baking or baker's yeast.
culture: As a noun, refers to a batch of micro-organisms in a
nutrient medium, such as a flour/water mixture. Could be "pure" (one
type of organism) or "mixed" (more than one type of organism).
damaged starch: Starch granules that have been broken in milling and
are therefore accessible to water and to amylase at temperatures
below the gelatinization temperature.
detente: French term for the rest period loaves get between the
division and rounding of the dough at the end of the fermentation
stage and the shaping of the loaves.
dough: A mixture of flour and water in which the weight of the water
is in or near the range of 60-75% the weight of the flour.
Dough yield (Teigausbeute): Common expression in bakery books and
articles translated from German. Same meaning as dough hydration,
except that the number is stated as 100 parts flour plus X parts
water equals dough yield. For example, a dough yield of 171 means a
hydration of 71%.
elasticity: The springiness that allows dough with well developed
gluten to stretch and return to its previous shape.
environmental surface: In this context, refers to a surface that can
inoculate a culture, intentionally or unintentionally. It could be
the surface of a flour particle, your hands, or a bowl. The
concentration and spectrum of organisms on such surfaces vary widely,
but is much greater than is found in the atmosphere.
extensibility: The quality (seen in wheat doughs only) of thin-film
strain hardening, which stabilizes the gas cells of a rising dough
and prevents the cells from breaking. This life-like quality can be
felt in the way a good dough complies with handling.
fermentation: Usually means the conversion of sugar to carbon
dioxide, alcohol, organic acids, and organic volatiles.
fermentation stage: Usually refers to a stage in breadmaking after
dough is mixed and before loaves are divided and shaped. Sometimes
referred to as "first proof."
fungi: Plants that lack chlorophyll, ranging from yeasts and molds to
mushrooms.
gelatinization: Uncurling and hydration of starch chains to form a
gel. Occurs as a suspension of starch granules is heated.
genetic engineering: The creation of lifeforms containing genetic
material from other species or genetic material altered in test tubes
and reimplanted into cells.
gluten: A protein complex prominent in wheat doughs. It is formed by
the association of two precursor proteins, glutenin and gliadin, and
by its strength, elasticity, and extensibility determines the
structure of the dough.
gluten window: "way of testing the level of gluten development in a
dough. Simply grab a small part of the dough between your fingers and
very gently and slowly stretch it apart. If the dough holds together
and stretches into a thin, tranluscent membrane then you've made the
window and know you've got good strong gluten.": see
"http://groups.google.com/groups?selm=3D20001025210953.00220.00001352%40n=
g-cq1.aol.com&output=3Dgplain"
hootch:The liquid layer that can accumulate in the top of a container
used to store a thin (very liquid) leaven.
humidity: The amount of water vapor (dampness) present in air.
hydration: Several meanings in this context: 1) The weight of water
in a a leaven or a dough, relative to the weight of flour. Therefore,
a dough at 70% hydration is 41% water, and a leaven at 100% hydration
is 50% water. 2) The capacity of a flour to absorb water (usually
called absorption). 3) The quantity of water in flour (related to
environmental humidity).
incubate: Encourage growth in a culture by maintaining conditions
that favor the growth of the organisms in the culture.
inoculate: To introduce a micro-organism to an appropriate medium for
its growth.
knead: To continue mixing a dough beyond the point when the
ingredients are uniformly distributed. This first causes abrasion of
flour particles, then suspension of starch granules and hydration and
linking of flour proteins.
lactobacilli: Rod-shaped bacteria that typically produce lactic acid
as the major end-product of their fermentation.
leaven: That which raises bread by producing carbon dioxide. In this
context, it is a batter, sponge, or dough that contains a mixed
culture of yeast and bacteria that has been continuously maintained
by a a series of inoculations and incubations.
levain: French for leaven.
Levain de tout point: The final leaven in the sequence of leaven
expansions in traditional French baking. Used to make up the dough.
liquid medium or media: A mixture of nutrients and water, in which
organisms may be propagated.
Malt: Dried and ground sprouted barley, high in amylase, that is
added to flour to guarantee that plenty of sugar is available to
fermentation. If excessive, leads to excessive dextrin formation,
slack doughs, and gummy crumb and crust.
mix: Used by professional bakers to include both mixing until the
dough mixture is blended AND for what others call kneading.
mutation: A change in the genetic makeup of a strain of organisms
that may lead to a change in structure or function.
mycologist: A scientist who studies fungi.
overproof: To allow the last stage of rising to last too long for the
temperature and fermentation activity of the dough. Makes slack
loaves, often with poor volume, shape, and crumb texture.
pH: A measure of the hydrogen ion concentration (on a logarithmic
scale) in a solution, from 0 to 14. Values less than 7 are acid,
while values over 7 are basic.
pointage: The fist rising after mixing (usually called the
fermentation stage). (French)
proof: Usually means the final stage of rising, after the loaves have
been shaped. Sometimes used ("first proof") to refer to the rise
after kneading and before loaves are shaped (fermentation stage), or
to a test done to see whether commercial yeast is still viable.
r.f.s.: Rec.Food.Sourdough-- Usenet group about natural leaven baking.
refreshment: Adding water and flour to a leaven to increase its
volume and feed its culture.
retarding: "Retarding simply means putting your loaves into cold
storage, the refrigerator, for awhile. This allows you to bake at a
later date, early in the morning if you wish, and it affords the
microorganisms in your dough a long, slow time to work, developing a
tastier and more sour bread." See
"http://groups.google.com/groups?selm=3D8t067u%245v%241%40nnrp1.deja.com&=
output=3Dgplain"
Sauerteig: Sourdough. (German)
selective breeding: Traditional type of genetic manipulation by
selection and propagation of organisms with desired characteristics.
sour: In this context, means a leaven, dough, or bread high in
lactate, acetic, and other organic acids.
sourdough: A bread, dough, or leaven that contains a mixed culture of
yeast and bacteria that have given it an acid pH.
sponge: A thick batter or thin dough with hydration somewhere above
75% and a little less than 100%.
sponge leaven: A sponge that has been inoculated with a leaven
culture, then incubated until it is ripe.
stable culture: One that has been propagated through many generations
and is not changing in its microbiological composition.
starter: Something that can be used to inoculate a sourdough culture.
Essentially the same thing as a leaven.
starter sponge: A ripe leaven of sponge consistency.
starter leaven: Could be used to describe a new sourdough culture,
being propagated from an infusion of flour (or fruit) in water.
storage leaven: One that is used to preserve the culture from one
baking session to the next. Usually kept in a refrigerator.
supernatant: The same as hooch the liquid that rises to the top of a
flour/water suspension that has settled.
symbiotic association: In this context, two micro-organisms that have
complementary metabolic needs and products, and resistance to toxic
products that each other produce. This makes their mixed culture more
robust and less susceptible to disruption by a third organism that
may be introduced.
temperature: Same as the conventional meaning-- the temperature of a
leaven or a dough can be influenced by the environmental temperature,
by the process of fermentation, and by mechanical work such as
kneading. Because fermentation is more vigorous at higher
temperatures and because the relative production of fermentation
changes with temperature, control or accommodation to temperature is
important in consistent baking.
time: The conventional meaning-- but it will need to be adjusted if
temperature is not controlled.
titratable acid: The amount of acid present, regardless of the pH of
the solution. The TA may be higher than expected if the buffering
effect of ingredients (flour with a high ash/mineral content) is high.
top-fermenting yeast: Brewer's yeast (ale yeast, S. cerevisiae) which
forms its initial fermenting mass in the top of a vessel of liquid.
The progenitor of commercial bread yeasts.
Vollsauer: The third and last stage of leaven expansion in German
baking. Some of this is saved to become Anstellgut, and the rest is
used to prepare the dough.
Wild yeasts: Used casually to refer to the yeasts in sourdough
leavens and doughs. They are not "wild" anymore when they are part of
a stable culture, but the term is used to differentiate them from
commercial yeasts.
yeast: Single-celled fungi that ferment sugars and produce CO2,
alcohol, and other organic products. There are many species, usually
differentiated by their metabolic/biochemical characteristics.
-Dan
------------------------------
Subject: 39. What factors affect microbial growth in sourdough?
We've been doing quite some work to figure out which factors affect
microbial growth in sourdough. I've done some work in vitro (which is
about to be published: Ganzle et al., Modeling of growth of
Lactobacillus sanfranciscensis and Candida milleri in response to
process parameters of the sourdough fermentation, Applied and
Environmental Microbiology, July 1998); and a colleague of mine,
Markus Brandt, has tried to figure out how my "model predictions"
work out during the actual dough fermentation. Taken together, one
can state the following:
For sourdough lactobacilli:
A) 32=B0C - 33=B0C (89.6F - 91.4F) -- optimum growth
B) 37=B0C & 20=B0C (98.6F & 68F) -- double generation time
C) 39=B0C & 15=B0C (102.2F & 59F) -- fourfold generation time
D) 41=B0C & 4=B0C (105.8F & 39.2F) -- no growth
For the yeasts, the figures are as follows:
A) 28=B0C (82.4F) -- optimum growth
B) 32=B0C & 20=B0C (89.6F & 68F) -- double generation time
C) 34=B0C & 14=B0C (93.2F & 57.2F) -- fourfold generation time
D) 35=B0C & 8=B0C (95F & 46.4F) -- no growth.
So: if several refreshments are done above 32 C, the yeasts will drop
out eventually. The optimum pH for lactobacilli is 5.0 - 5.5 (which
is the initial pH of a sourdough with 5 - 20% inoculum), the minimum
pH for growth is 3.8 (they usually produce acid until pH 3.6 is
reached).
Lactic or acetic concentrations don't affect growth of lactobacilli
very much: this is the reason why the buffering capacity of the flour
is so important for the organism (a high buffering capacity in high
ash flours means that the lactobacilli produce much acid until the
critical pH is reached). It also means, that in doughs that are
continuously operated with a high inoculum (more than about 30%),
you'll find more yeasts and fewer lactobacilli. Eventually, the
lactobacilli flora may change, with more acid tolerant lactobacilli
(e.g. L. pontis) prevailing. Such a sourdough is found in the Vollmar
and Meuser continuous sourdough fermentation machines (there are 6
operating in Germany, and a diploma candidate in our department
characterized the microflora of several of these: as the machine is
operated with a 50% inoculum, the pH is never above 4.1 - 4.3, and no
L. sanfranciscensis is found in those doughs).
Yeasts are different: they don't mind the pH at all, but are strongly
inhibited by acetic acid, and to a much lesser extent by lactic acid.
Increasing salt concentrations inhibit growth of lactobacilli, but
yeasts tolerate more salt. No salt is added to the sourdough until
the final bread dough, but the dough yield affects the salt
concentration: with a low dough yield (little water), the salt (ash)
is dissolved in a smaller water volume, and the salt concentration
goes up: resulting in a slower fermentation.
So much for the "in vitro" theory. Surprisingly, Markus has found
most of the predictions to come true when he was looking at the cell
counts at different temperature, size of inoculum, salt
concentration, and pH in rye dough. The variation of the inoculum
size was interesting: If he reduced the inoculum size by 2, he had to
wait almost exactly one generation time (one doubling time of the
lactobacilli) longer until the dough has reached the same cell
counts, pH, titrable acidity, and so on as the dough with the higher
inoculum. This was true for inoculum sizes between 1% and 20%: at 50%
inoculum, the pH is so low that the lactobacilli don't really grow
well, and at an inoculum size of 0.1%, the pH and/or the oxygen
pressure in the dough are so high that the cells have a lag-time (see
above) of an hour. Thus, a scanty inoculum means one generation time
longer fermentation.
The generation time of L. sanfranciscensis in rye dough at 28 C is a
little less than an hour (figures may vary with different strains in
different flours, but it's not much more or less than that), so if
the inoculation size is reduced from 20 to 2.5%, it'll take about
three hours more until the dough is ripe.
The question is, whether these findings are true for all flours and
for all organisms. The strain isolated by Kline and Sugihara does not
differ very much from the two strains I've been looking at. All the
literature available tells me that - as long as we're looking at
sourdoughs with a tradition of continuous propagation - the system
behaves the same way. Differences may be between rye flour and white
wheat flour: in white wheat flour, the enzyme activities are so low
that the organisms may run out of food before the critical pH
(lactobacilli) or the critical acetic acid concentration (yeasts) is
reached.
-Michael
------------------------------
Subject: 40. Should I use an established starter or make my own starter?
Well, it all depends on whether you are interested in sourdough
baking because you want to make good bread or whether you are also
interested in the challenge of creating your own sourdough starter.
Even with a predictable starter culture, sourdough baking can be
occasionally tricky. For someone who has never baked sourdough bread
before and may be experiencing trouble, beginning with a predictable
starter eliminates one possible source of trouble.
How do "established" starters get that way? They are propagated for
years and years, generations and generations. Also, "established"
starters are the end result of selective disposal. For every
100-year-old starter there were countless starters that thrown away
because their properties were simply not special enough to merit
saving. People did, in fact, give up on all those other starters.
Further, it is a relatively well-accepted fact that certain special
properties in sourdough cultures don't come into being until a
certain amount of time has passed. For example, one can reasonably
expect that the symbiotic relationship between microorganisms that
have coexisted in a starter for several decades will be much stronger
than what is found in a months-old starter culture. This is one
reason why these old, established sourdough cultures are such
consistent performers and are often quite resistant to
change/invasion by other sourdough microorganisms.
So the question becomes whether you want to learn how to surf or
whether you want to learn how to make your own surfboard. Most
people would agree that it makes a lot more sense to learn how to
surf first, rather than doing both at the same time. Billyfish
illustrates this well in his posting. Here is a guy who has been
struggling for a long time with various starter recipes. He finally
gets some satisfaction, finally feels like he can experiment with his
technique and concentrate on making the kind of bread he wants
*after* acquiring a proven starter from SDI. I think he sums it up
perfectly by saying "I now have a starter that is sufficiently
predictable to allow experiments to proceed."
*This* is why so many of us recommend starting with an established
sourdough culture.
-Sam
------------------------------
Subject: 41. Can I use metal utensils with sourdough?
A sourdough starter is acidic. Prolonged contact of your acidic
starter with metal will discolor your metal utensil and dissolve tiny
amount of the metal into the starter if you leave it for, say, weeks.
So it is not a good idea to keep a sourdough starter in a metal
container unless you want discolored, or given years of contact,
damaged utensils. Your starter, or you, may not like the small amount
of metal that is dissolved into the starter either.
So use a starter container made of a material that is not affected by
acid. My personal preference are standard wide mouth glass quart
canning jars, also known in North America as Mason jars. Mason jars
are readily available and the wide mouth makes them easy to clean.
Glass is highly acid resistant, very easy to clean and sterilize,
which makes it a preferred material for starter storage.
In the short time of mixing and rising of sourdough bread, the effect
of a slightly acidic mix is not noticeable on metal utensils, such as
spoons and bowls. So there is simply no problem in using metal
utensils, especially stainless steel utensils, to make sourdough
bread.
-Darrell
------------------------------
42. What is a good source for technical information on sourdough starter=
s?
Here are links to several useful and interesting technical sources :
The first four URLs are noted as "Long Technical Posts 1-4" by Dan
Wing and are correspondence from Michael Gaenzle to Dan Wing. Michael
is commenting on the first proof of Dan's book, The Bread Builders -
Hearth Loaves and Masonry Ovens' by Dan Wing and Alan Scott, an
excellent book by the way.See
http://www.nyx.net/~dgreenw/whataboutdanwingsnewbookth.html for my
review.
Long Technical Post 1 by Dan Wing
Long Technical Post 2 by Dan Wing
Long Technical Post 3 by Dan Wing
Long Technical Post 4 by Dan Wing
More technical correspondence by Dan Wing
Sam Kinsey with some quotes and comments on yeast growth
Sam Kinsey with some quotes from the American Association of Cereal
Chemists site
Search over 38 years of Cereal Chemistry Abstracts at
http://www.scisoc.org/aacc/searchcs/
-Sam/Darrell
------------------------------
43. How do I convert yeast bread recipes to SD recipes?
When converting recipes to sourdough I always make sure that I build
my "sponge" with the smallest possible inoculum (usually a
tablespoon). This way, you know exactly how much water and flour you
are using (it's never easy to tell how much of what you're actually
getting when you take starter directly from the jar unless you weigh
the ingredients and maintain a 1:1 starter).
In general, I think it is a good idea to build a nice active sponge
that contains somewhere between 5% and 20% of the total flour in the
recipe. You will want to experiment with the percentage of sponge to
see which results you like.
Here is a hypothetical example of what I mean: Let's say that the
original recipe calls for 1000g of flour, 600g water, 20g salt and
20g yeast... If I wanted a 20% inoculum, I would make a sponge using
200g (20% of 1000g) flour, 300g water and one tablespoon of starter.
Once the sponge was nice and active, I'd mix the sponge with 800g
flour, 300g water and 20g salt. By using this method, I know that my
dough has exactly the same amount of flour/water as the original
recipe. At this point, all I have to do is mix the ingredients
according to the recipe, proof and bake. The "new" version of the
recipe should turn out very similar to the original, since the only
substantial difference is in method of leavening.
Two things to keep in mind: 1. One cannot generally do multiple
risings with sourdough as with yeast doughs. The rising schedules
called for in the original recipe should be modified with this in
mind. 2. The defining characteristics of certain bread styles seem
fairly dependent on fast-acting yeast. For example, a sourdough
baguette or a sourdough ciabatta will not be all that similar to the
original.
-Sam
------------------------------
44. What is meant by a "fully activated" starter?
You want to mix your dough when your starter (or sponge) is fully activat=
ed.
I'd suggest that you take a few days and get to know your starter and
its cycles. You might want to find some sort of container that you
can mark - either with a pen or a piece of tape or you can tape a
strip of paper vertically on the container and use that. Glass
canning jars work well and you can easily see into them, or anything
else that's straight-sided (easier to judge volume increases than
flared-sided containers, like most bowls).
Take a little starter and feed it, in whatever ratio of starter to
new food you intend to use regularly (I tend to use 1 oz starter and
add 6 oz combined flour and water (or even 4 oz combined water and
flour if I'm going to be doing a number of feeding cycle), but use
what you are comfortable with). Feed the starter and then just watch
it. Every hour mark the container as to the level of the starter.
Check it after 12 hours. If it's started to separate and form hooch,
feed it again. If not, leave it for another 12 hours.
Next time you feed it, discard most of the starter (or use it bake
with or to build a sponge) and add your water and flour (I do the
same as I described above, discard down to 1 oz, add water & flour.
I add equal amounts of water and flour by weight, not by volume (I
just find it easier, and I always know how much of an amount of
starter is water and how much is flour). This gives me a pretty
thick starter, which is my preference).
The cycle of a starter after being fed and left to sit out at room
temp is: - for a while, it looks like nothing is happening - then you
will notice small bubbles beginning to form - the volume will start
to increase - this will go on for some time, with more and more
bubbling and increasing in volume - eventually, the starter will be
fully activated. At this point, it should be full of bubbles which
are well-integrated throughout the starter (not just on top) and it
may have a layer of foam or froth on the very top. If you starter is
a very thin consistency, you may instead have a couple of inches of
foam on the top and not so much bubbling within the starter. If your
starter is thick enough, it will have at least doubled in volume.
This is called the starter's "Peak". - it will stay at this level for
a some amount of time. - eventually the starter will sort of fall
back into itself, the volume will drop and the bubbling will
decrease. - at some point later, the starter will have evened out, no
bubbling will be present, and the starter will be a calm, thin batter
sitting in the bottom of your container. - eventually, it will begin
to separate and form hooch.
It's my understanding that peak yeast activity occurs while the
starter is plateauing or just starting to fall back into itself, and
that this is the optimum time to use the starter.
How long a cycle takes depends on several things: - the starter
itself, and the mix of organisms in the starter - the consistency of
the starter (thick ones take longer than thin ones) - the temperature
at which the starter is sitting (as well as the temp the starter was
when you began and the temp of the water & flour used) - possibly
your altitude (slower at high altitudes) But as a general rule, a
cycle takes 8 - 12 hours but some starters, like SDI's Russian
Starter, are much faster than that.
So, my suggestion is that you put your starter through some feeding
cycles and pay attention to what it does. Not that you need to watch
it every minute, but check on it every hour or so and mark it's
level, or keep notes of the time and what the starter looks like.
Then you can play around with activating it at different temperatures
or different consistencies and see how that change affects it.
If you do this, you'll really get to know your starter. You'll know
what it looks like when it's fully activated (at it's peak), or where
it is in its cycle, and how long everything takes. This will give
you a much better handle on baking with the starter.
One thing you'll notice as you read some of the sourdough literature
is that there are discrepencies and variances with just about every
aspect of starter maintenance and baking procedures. Keep in mind
that there is no one, true way when it comes to sourdough. The stuff
is so flexible, adaptable and variable, that all kinds of procedures
and methods work with it. The trick is to experiment and find out
what works for you, with your starter, in your environment. It takes
a bit of experimentation to find that for yourself, though. Keep
talkin' and keep readin', you'll come across lots of people's ideas
that you can try out.
-Beth
------------------------------
45. What about Dan Wing's new book "The Bread Builders"?
I had a very interesting book pop through the mail slot recently,
'The Bread Builders - Hearth Loaves and Masonry Ovens' by Dan Wing
and Alan Scott.
When Dan wrote me for my address so he could send me a review copy he
noted in his enthusiasm for his newly minted book "It's a really good
book." After receiving it yesterday I noted in my enthusiasm for his
newly minted book, "It's a really good book" and it is :-).
You get for your $35 the best book I have read on "natural leavens"
or sourdough. It has no recipes but sets out to teach you the basics
underlying baking bread with no commercial yeast... and succeeds very
well. The book is 254 pages, paperback, indexed, and well illustrated
with color and b&w photographs, graphs, line drawings and a glossary.
Starting out with interesting introductions by Alan Scott and Dan
Wing, the book's chapters wind their way through Naturally Fermented
Hearth Bread, Bread Grains and Flours, Leavens and Doughs, Dough
Development and Baking, Ovens and Bread.
Interspersed in the chapters are 'visits' where a separate article
describes a visit to an interesting bakery or baking related location
ranging from Vermont to California. The book's clear and easily
readable style is assisted with sidebars and notes clarifying various
points. I do like the notes in the margins as this book does rather
than at the bottom of the page.
But wait, that is only half the book. You get thrown in for free
another book, on how to design, build and operate a masonry oven. Its
chapters range through Masonry Ovens of Europe and America, Preparing
to Build a Masonry Oven, Masonry Materials, Tools and Methods, Oven
Construction, Oven Management and A Day in the Life at the Bay
Village Bakery. If you are not up to rushing out to build a masonry
oven right away, 3 methods are given to approach the results in a
masonry oven, cloche, baking stone, and you'll have to read the book
to see what I am going to be doing with a metal pot, cookie sheet and
pie plate.
All in all I believe this book is a good read for aficionados of
sourdough, and they would find it a good reference work for inclusion
in their library. As a book for someone switching from baking yeast
bread to "natural leaven" bread they would probably regard ownership
of this book as priceless gift. For someone starting out in bread
baking it would allow them to get a really good understanding without
all the "old wive's tales" that unfortunately dog some sourdough
advice. I know it will find a treasured place in my library and be
well thumbed through as it assists me in achieving the perfect loaf.
Thanks Dan.
-- Darrell
p.s. The publishers are Chelsea Green Publishing, 1 800 639 4099,
http://www.chelseagreen.com, ISBN number is 1-890132-05-5, $35 also
at Amazon ~$28 http://www.amazon.com/exec/obidos/ASIN/1890132055/
------------------------------
46. What's all this about natural leaven and L. sanfranciscensis?
Dan wrote: "I chose to write "natural leaven" because it is less
awkward than 'mixed ferment cultured from the environment and
sustained with repeated inoculation.'" -- Dan
Michael replied: "Sustained with repeated inoculation" is better than
anything I was writing to say the same thing. "Cultured from the
environment" is certainly true - L. sanfranciscensis and the yeasts
must come from somewhere - but somewhat misleading, as these
organisms most probably do not originate from the grain, or the flour
(Marco Gobbetti, whom I mentioned earlier has been looking for L.
sanfranciscensis on all kinds of Italian wheat flours, and he has not
found any.
In every Italian dough "sustained with repeated inoculation" you'll
find L. sanfranciscensis to be the dominating species, though. No
other scientist has been able to isolate L. sanfranciscensis from any
other source than sourdough, but all sourdough "sustained etc."
contain this organism as the dominating flora.
A possible source may be the humans: there are all kinds of
lactobacilli thriving in the mouth, the intestines, etc. Hammes met a
South African Microbiologist who claimed to have isolated L.
sanfranciscensis from the teeth of pre-school children. The data is
not published, so I don't know what science is behind this claim.
But, whereever L. sanfranciscensis comes from, it most probably does
not come from the flour.
...
I think it does not matter when the first batch of a new sourdough
stinks - the good bacilli will come out eventually, and they may come
faster if fermentation is done around 25 - 30=B0C (as mentionned
earlier, the temperature optimum of L. sanfranciscensis is 32 -
33=B0C). There has been nice work done in Rudi Vogels lab on the
microflora of a freshly started sourdough: first, there are
Enterobacteria (Escherichia coli, Salmonella, Enterobacter), highly
undesirable organism that stink terribly, then there are
homofermentative lactobacilli (good, but no gas production), then
acid-tolerant, heterofermentative
lactobacilli. I think, this took about 48 hours at 30=B0C. The stink at
the beginning does not matter as the organisms will be diluted out or
die eventually.
No L. sanfranciscensis, though, these will occur only after repeated
refreshments. Peter Stolz of the B=F6cker company told me that it takes
about two weeks of repeated inoculations to get a good
"sanfranciscensis" sourdough. I don't know whether or not this
process was sped up in his case as, due to his workplace, his skin is
all covered with L. sanfranciscensis.
-- Michael
--------------------------
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47. How does one measure the ph of sourdough, and what is the effect
of different ph's?
For sponges and doughs:
*Weigh 15 g of sponge or dough and place it in a polyethylene container.
*Add 100 ml of distilled water to this sample.
*Seal the container and shake until the sponge or dough sample has
completely dispersed.
*Place electrode(s) in the mixture and read the pH value.
*After the pH value has been obtained and recorded, slowly add 0.1N
NaOH from the buret and stir constantly until a constant pH of 6.6
is obtained. Read the buret and record the number of ml of NaOH used
(that is the TTA or Total Titritable Acidity). Take care not to add
the NaOH too rapidly to avoid going beyond pH 6.6.
For bread:
*Weigh 15g of bread, excluding the crust, into a clean dry container.
*Add 100 ml of distilled water, seal the container and shake until
bread disperses into a semi-liquid mixture.
*Determine and record pH and TTA as described for brew.
Some useful information for all you "sourheads" out there:
Overmatured sours, i.e., replenished sours matured over 8 hours at
77F, may build up excessive acidity and the lactic acid bacteria will
start to inhibit the propagation of yeast cells, i.e., slowing the
leavening activity in the sourdough.
A good and fully matured functional sour has a pH of 3.9-4.1 and a
total titratable acidity (TTA) of 13-15 ml. Sours that develop
acidity equal to a TTA of 18-22 ml or higher with a pH of 3.8 or
lower will gradually lose their ability to produce enough carbon
dioxide to leaven bread loaves. Having a high acid content also makes
doughs softer and makes their cell structure break down during
rounding and moulding. This tends to result in an irregular cell
structure with thicker cell walls in the bread crumb and a tougher
bite. This effect is intensified in doughs with a relatively high
water absorption (over 62% of flour weight). However (for all you
artisans out there), bread of this type is acceptable as "signature"
bread served in restaurants or for personal use or for artisan type
bakeries.
Other useful information concerning industry "normal" pH and TTA in
breads and their process:
Sourdough starter 3.9-4.1 pH 14-16 TTA
Mixed dough 4.6-4.8 pH 5-7 TTA
Proofed dough 4.2-4.4 pH 9-13 TTA
Crumb 4.3-4.5 pH 6-7 TTA
*TTA values are expressed as ml of 0.1 N NaOH per 20g sample
(sourdough starter containing 47.6% flour) titrated to pH 6.6
**This is according to the American Institute of Baking, and not the
FDA, so I imagine that would explain some differences in "normal" pH
readings.
-- Dave
-----------------------
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48. Should I use more than one rise for my bread?
Some will tell you "one rise is best". Others feel that you can get
a finer crumb with multiple risings. Some feel that you can't get
good rise on second, or third, risings. Others feel one rise is not
enough, that good bread requires more than one rising.
Some people report good rises on second and third risings, others say
the second stays as flat as a pancake.
Looking at the posts, I think there are a number of factors at work.
Here are some of them:
1. The starter is an obvious difference, as some are more lively than ot=
hers.
2. The baker's technique. A bit of gentle kneading is required
between rises or the culture (or even baker's yeast) can't get to the
nutrients in the dough.
3. Altitude. If someone is at a higher altitude, it's easier to get
second, third, fourth, or more risings than at lower altitudes.
Let's think in terms of higher altitudes being above a mile or so
above sea level.
4. Flour - some flours have more nutrients than others, so some will
keep feeding the culture longer, and let the bread rise better. Some
have more, or less, gluten which also impacts rising. Some cultures
will degrade gluten if they are allowed to work too long, which can
tie into number 1, above.
5. The recipe. If the recipe provides other nutrients for the
culture, or has ingredients that interfere with the culture's
working, that can be an issue also.
6. Expectations. What is "a well risen loaf"? Some people look for
big holes in their bread, others for small. Some want a light fluffy
loaf, others want a dense loaf. All call their loaves "well risen".
On the pan front, a pan helps a loaf hold it's shape. To be a bit
indelicate, think of a woman past her youth with, and without, a bra.
A pan helps dough hold it's shape on five sides. A free form loaf
has support only on the bottom.... or no support at all. So the free
form loaf has to have good structural integrity to maintain it's
shape. With higher hydration doughs, this becomes more of a
challenge to the baker.
-- Mike
In my opinion, people new to sourdough bread baking should remain
with one rise until they are satisfied with their bread density.
People converting their bread baking from baker's yeast should also
use one rise initially, as they will not be familiar with the
enzymatic degradation of the dough one gets with sourdough, nor be
familiar with the much slower rise times of sourdough bread.
-- Darrell
-----------------------
49. What is Salt Rising Bread?
Salt rising bread (SRB) is leavened by the bacterium Clostridium
perfringens rather than a yeast as used in sourdough.
I have described two reliable recipes in an article presented in
Petits Propos Culinaires No.70 (PPC is published in England and
focuses on history of cuisines and foodstuffs).
I have improved one recipe to speed the process to deliver two loaves
of SRB by mid-day after setting a pre-starter the evening before. If
you adhere to the following, you can do the same.
In the early evening, set the pre-starter -
Two cups of scalded milk, immediately after
removing from heat,
Stir in two cups of corn meal, and
Three tablespoons of wheat gluten.
Cover the container loosely with plastic wrap or similar and place it
in a space that can maintain a temperature between 95 and 105 degrees
Fahrenheit. The temperature is important - ten degrees less and
action slows dramatically.
First thing in the morning, make up the starter -
To the pre-starter, stir in,
One cup hot tap water (~125F),
One-and-a-half cup flour,
One-half teaspoon bicarbonate of soda.
Loosely cover the container and return it to the heat box. In about
two hours the slurry will be covered with bubbles or foam and will
have increased volume by 10 or 15 percent. When it reaches this
state;
Make up the dough, add to the starter -
One tablespoon sugar,
One teaspoon salt,
Three tablespoons shortening (oil or solid), and
Flour enough to make a stiff dough (heat the flour
till warm to the touch).
Old age inspired purchase of a KitchenAid mixer; it now does the
kneading. When making up the SRB dough, I fit the dough-hook, heat the
bowl by rinsing with hot water, and add three cups of flour plus the
starter. I let this slurry become somewhat uniform to then continue addi=
ng
flour until the machine seems to groan (5 or 6 cups, perhaps). I don't
have another rule of thumb for judging "enough" for the dough - probably
five minutes total time stirring by the time the last of the flour has be=
en
added. The finished dough is somewhat sticky and seems tough.
Divide the dough in two, form loaves, and place in greased pans. Oil
the surface, if you please. Put the pans into the heat box for about
two hours when the dough will have risen to the pan edge. Bake in
350F oven for an hour or until nicely browned.
Any kind of corn meal will be satisfactory (organic, inorganic,
white, yellow, stoneground, ripped to shreds by steel,
what-have-you). Every grain I have tried has produced a satisfactory
starter. Oak bark will inspire a starter in my experience.
The secret to a fast and reliable process is the heat and gluten. Of
the two, the heat is probably most important.
-- Reinald
In subsequent correspondence Reinald comments:
I have made SRB for about 40 years with the early years as confused
as many people are today. In 1981 I discovered that a fraction of
Campden tablet did a much better job of killing yeast than does salt.
A couple of years ago, after e-mail exchanges with Susan Ray Brown, I
repeated the 1981 experiments with different grains (oat meal, corn
grits, barley, etc.) and went on to try just about everything I could
find at the local natural foods store (wheat flakes, wheat bran, rye
flakes, oat bran, steel cut oats, etc.) Practical SRB starters will
develop from all of them.
Venturing further afield, I tried slivers of bark from white oak
(Quercus alba) and black locust (Robinia pseudoacaca) as initiators
on wheat flour with Campden; again to obtain useful starters. Next
was cheddar cheese and blue cheese and, finally, flour alone. All
worked.
A professional food chemistry laboratory ran DNA analyses on the
Clostridium strains in flour, corn meal, and cheddar cheese mediated
starters. The cheese Clostridium was perfringens Type A with an
exact match to their reference pattern; flour and corn had patterns
quite similar to the Type A, but not identical.
I also monitored pH of various starters as they developed.
Perfringens thrives in a basic solution even as it is producing acid
which eventually arrests activity. Bicarbonate of soda buffers the
acid to facilitate perfringens action; it is not part of the
leavening process.
-- Reinald
-----------------------
Subject: 99. Authors
Dick -Dick Adams -- dick.adams (at) att.net
David -David Auerbach -- auerbach (at) unity.ncsu.edu
Mike -Mike Avery -- http://www.sourdoughhome.com
Beth -Beth -- housewolf (at) hotmail.com
Troy -Troy Boutte -- tboutte (at) delphi.com
Michael -Michael Ganzle -- michael.gaenzle (at) blm.tu-muenchen.de
Carl -Carl Griffith -- (deceased)
Dave -Dave J. -- thebakery (at) worldnet.att.net
George -George Kavanagh -- GK05 (at) earthlink.net
Sam -Sam Kinsey -- slkinsey (at) aol.com
Andreas -Andreas Krueger -- andreas.krueger (at) neuss.netsurf.de
Matt -Matt -- mel63 (at) capital.net
Reinald -Reinald S. Nielsen -- n984652 (at) hypernet.com
Jeff -Jeff Renner -- jsrenner (at) umich.edu
Roland -Roland Salandha -- rsaldanh (at) magnus.acs.ohio-state.edu
Dan -Dan Wing -- wagons (at) sover.net
Jonathon -Jonathan Youngman -- jonathan (at) west.net
Edited by Darrell Greenwood -- darrell.web (at) telus.net
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