From: Darrell_Greenwood@mindlink.net Newsgroups: rec.food.sourdough,rec.answers,news.answers Subject: rec.food.sourdough FAQ Questions and Answers Supersedes: <food/sourdough/faq_869133072@rtfm.mit.edu> Followup-To: rec.food.sourdough Date: 5 Aug 1997 09:39:09 GMT Organization: http://www.nyx.net/~dgreenw/ Expires: 6 Sep 1997 09:35:28 GMT Message-ID: <food/sourdough/faq_870773728@rtfm.mit.edu> Reply-To: Darrell_Greenwood@mindlink.net Summary: This posting is a collection of interesting and knowledgeable answers to frequently asked questions on newsgroup rec.food.sourdough. Keywords: FAQ sourdough bread X-Last-Updated: 1997/07/18 Archive-name: food/sourdough/faq Posting-Frequency: 18 days Last-modified: 1997/05/17 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; FAQ.starter.doctor, Basic.Bread.faq, and sourdough.recipes.faq and other archived information already in existence at the FAQ archive sites pointed to and hot linked by URL; http://www.nyx.net/~dgreenw/sourdoughfaqs.html This URL has additional information on starter sources and a growing number of links to resources other than the archive sites. 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/sourdough/. This way appears quite limited in number of connections permitted. I recommend using the http server at unc 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 FAQ.Starter.Doctor, is also archived at rtfm.mit.edu (18.181.0.24) in the directory /pub/usenet/news.answers/food/sourdough/ as 'faq' and 'starters'. 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: send usenet/news.answers/food/sourdough/faq or send usenet/news.answers/food/sourdough/starters in the body of the message. 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? 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 ------------------------------ 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 ------------------------------ 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 ------------------------------ 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 ------------------------------ 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? 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, at http://www.cyberhighway.net/~sourdo. Email sourdo@cyberhighway.net or their snail mail address is PO Box 670, Cascade ID 83611. -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 ------------------------------ 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 ------------------------------ 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 (=kg 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: 99. Authors Dick -Dick Adams dick.adams@bigfoot.com Dan -Dan Wing Wagons@ConnRiver.net David -David Auerbach auerbach@unity.ncsu.edu Troy -Troy Boutte tboutte@delphi.com George -George Kavanagh george.kavanagh@wang.com Jeff -Jeff Renner nerenner@umich.edu Michael -Michael Gaenzle ganzlem@Uni-Hohenheim.DE Roland -Roland Salandha rsaldanh@magnus.acs.ohio-state.edu Jonathon -Jonathan Youngman jonathan@west.net Edited by Darrell Greenwood. Darrell_Greenwood@mindlink.net -- Darrell Greenwood, Vancouver, BC darrell_greenwood@mindlink.net My web homepage... http://mindlink.net/darrell_greenwood/
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