ATCC: American Type Culture Collection (www.atcc.org), a source for pure strains of micro-organisms, including those that predominate in natural leavens.
absorption: The ability of a flour to take up and hold water. Generally higher for high-gluten flours and those with relatively high damaged-starch levels.
acid: A solution containing free hydrogen ions, or a substance that will release them when dissolved in water.
acid pH: Since pH is a measure of the acid/base state of a solution, "acid pH" indicates that the solution in question is acid, and a has a pH of less than 7 on a scale of 14.
acid tolerance: The ability of a micro-organism to grow in acid conditions.
active starter: A leaven that has recently reached its equilibrium yeast and bacterial population. If thick, it will be spongy, tenacious, and gassy. If thin, it will be frothy and bubbly.
amylases: Enzymes present in grain but also supplemented by millers, capable of breaking damaged starch down to sugars and dextrins. These sugars then power fermentation and contribute to carmelization and the Maillard reactions (browning of the crust).
Anfrischsauer: The first stage (first expansion) of the traditional German baking sequence, made from Anstellgut, water, and flour.
Anstellgut: The inoculant to the first stage in the three-stage sequence of expansion of a leaven culture in the traditional German bakery. It is a portion of the ripe sourdough from the previous day.
ash content: The mineral content of flour.
autolyse, autolysis: A rest during kneading (5-20 minutes) to allow the dough to continue hydrating and the developing gluten to relax before kneading is resumed and the gluten is taken to full development. Usually done when dough is being machine-mixed.(French, English)
bacteria: Single celled organisms with no defined chromosomes (yeast don't have defined chromosomes either). Neither plant nor animal. Usually smaller than yeasts. Some can ferment, but usually don't make CO2 in the same amounts as yeast under typical conditions-- they make organic acids instead.
bake: Heat to an internal temperature of at least 195 degrees Fahrenheit in a dry environment. For hearth loaves (not in a pan) the environment should be humid initially, then dry.
baker's yeast: Strains of brewer's yeast selected and commercially produced for raising dough.
baking yeast: Same.
batter: A thin mixture containing flour and water, in the range of 100% hydration or higher.
barm: A leaven or starter, sometimes implying one made from brewing sediment. (English)
beer yeast: Brewer's yeast selected for making beer.
biga: Originally the same as starter or leaven (natural leaven) but now used to refer to a sponge raised with commercial yeast. (Italian)
bottom-fermenting yeast: Brewer's yeast (lager yeast, Saccharomyces uvarum) which forms its fermenting mass in the bottom of a vessel of liquid.
chef: A piece of a previous batch of dough kept over to inoculate a new flour/water mixture, which will then become a leaven, starter, sponge (synonyms).
commercial yeast: Factory-produced yeast. The species is the same as brewer's yeast, but the characteristics may be very different. This term includes baking or baker's yeast.
culture: As a noun, refers to a batch of micro-organisms in a nutrient medium, such as a flour/water mixture. Could be "pure" (one type of organism) or "mixed" (more than one type of organism).
damaged starch: Starch granules that have been broken in milling and are therefore accessible to water and to amylase at temperatures below the gelatinization temperature.
detente: French term for the rest period loaves get between the division and rounding of the dough at the end of the fermentation stage and the shaping of the loaves.
dough: A mixture of flour and water in which the weight of the water is in or near the range of 60-75% the weight of the flour.
Dough yield (Teigausbeute): Common expression in bakery books and articles translated from German. Same meaning as dough hydration, except that the number is stated as 100 parts flour plus X parts water equals dough yield. For example, a dough yield of 171 means a hydration of 71%.
elasticity: The springiness that allows dough with well developed gluten to stretch and return to its previous shape.
environmental surface: In this context, refers to a surface that can inoculate a culture, intentionally or unintentionally. It could be the surface of a flour particle, your hands, or a bowl. The concentration and spectrum of organisms on such surfaces vary widely, but is much greater than is found in the atmosphere.
extensibility: The quality (seen in wheat doughs only) of thin-film strain hardening, which stabilizes the gas cells of a rising dough and prevents the cells from breaking. This life-like quality can be felt in the way a good dough complies with handling.
fermentation: Usually means the conversion of sugar to carbon dioxide, alcohol, organic acids, and organic volatiles.
fermentation stage: Usually refers to a stage in breadmaking after dough is mixed and before loaves are divided and shaped. Sometimes referred to as "first proof."
fungi: Plants that lack chlorophyll, ranging from yeasts and molds to mushrooms.
gelatinization: Uncurling and hydration of starch chains to form a gel. Occurs as a suspension of starch granules is heated.
genetic engineering: The creation of lifeforms containing genetic material from other species or genetic material altered in test tubes and reimplanted into cells.
gluten: A protein complex prominent in wheat doughs. It is formed by the association of two precursor proteins, glutenin and gliadin, and by its strength, elasticity, and extensibility determines the structure of the dough.
gluten window: "way of testing the level of gluten development in a dough. Simply grab a small part of the dough between your fingers and very gently and slowly stretch it apart. If the dough holds together and stretches into a thin, tranluscent membrane then you've made the window and know you've got good strong gluten.": see "http://groups.google.com/groups?selm=20001025210953.00220.00001352%40ng-cq1.aol.com&output=gplain"
hootch:The liquid layer that can accumulate in the top of a container used to store a thin (very liquid) leaven.
humidity: The amount of water vapor (dampness) present in air.
hydration: Several meanings in this context: 1) The weight of water in a a leaven or a dough, relative to the weight of flour. Therefore, a dough at 70% hydration is 41% water, and a leaven at 100% hydration is 50% water. 2) The capacity of a flour to absorb water (usually called absorption). 3) The quantity of water in flour (related to environmental humidity).
incubate: Encourage growth in a culture by maintaining conditions that favor the growth of the organisms in the culture.
inoculate: To introduce a micro-organism to an appropriate medium for its growth.
knead: To continue mixing a dough beyond the point when the ingredients are uniformly distributed. This first causes abrasion of flour particles, then suspension of starch granules and hydration and linking of flour proteins.
lactobacilli: Rod-shaped bacteria that typically produce lactic acid as the major end-product of their fermentation.
leaven: That which raises bread by producing carbon dioxide. In this context, it is a batter, sponge, or dough that contains a mixed culture of yeast and bacteria that has been continuously maintained by a a series of inoculations and incubations.
levain: French for leaven.
Levain de tout point: The final leaven in the sequence of leaven expansions in traditional French baking. Used to make up the dough.
liquid medium or media: A mixture of nutrients and water, in which organisms may be propagated.
Malt: Dried and ground sprouted barley, high in amylase, that is added to flour to guarantee that plenty of sugar is available to fermentation. If excessive, leads to excessive dextrin formation, slack doughs, and gummy crumb and crust.
mix: Used by professional bakers to include both mixing until the dough mixture is blended AND for what others call kneading.
mutation: A change in the genetic makeup of a strain of organisms that may lead to a change in structure or function.
mycologist: A scientist who studies fungi.
overproof: To allow the last stage of rising to last too long for the temperature and fermentation activity of the dough. Makes slack loaves, often with poor volume, shape, and crumb texture.
pH: A measure of the hydrogen ion concentration (on a logarithmic scale) in a solution, from 0 to 14. Values less than 7 are acid, while values over 7 are basic.
pointage: The fist rising after mixing (usually called the fermentation stage). (French)
proof: Usually means the final stage of rising, after the loaves have been shaped. Sometimes used ("first proof") to refer to the rise after kneading and before loaves are shaped (fermentation stage), or to a test done to see whether commercial yeast is still viable.
r.f.s.: Rec.Food.Sourdough-- Usenet group about natural leaven baking.
refreshment: Adding water and flour to a leaven to increase its volume and feed its culture.
retarding: "Retarding simply means putting your loaves into cold storage, the refrigerator, for awhile. This allows you to bake at a later date, early in the morning if you wish, and it affords the microorganisms in your dough a long, slow time to work, developing a tastier and more sour bread." See "http://groups.google.com/groups?selm=8t067u%245v%241%40nnrp1.deja.com&output=gplain"
Sauerteig: Sourdough. (German)
selective breeding: Traditional type of genetic manipulation by selection and propagation of organisms with desired characteristics.
sour: In this context, means a leaven, dough, or bread high in lactate, acetic, and other organic acids.
sourdough: A bread, dough, or leaven that contains a mixed culture of yeast and bacteria that have given it an acid pH.
sponge: A thick batter or thin dough with hydration somewhere above 75% and a little less than 100%.
sponge leaven: A sponge that has been inoculated with a leaven culture, then incubated until it is ripe.
stable culture: One that has been propagated through many generations and is not changing in its microbiological composition.
starter: Something that can be used to inoculate a sourdough culture. Essentially the same thing as a leaven.
starter sponge: A ripe leaven of sponge consistency.
starter leaven: Could be used to describe a new sourdough culture, being propagated from an infusion of flour (or fruit) in water.
storage leaven: One that is used to preserve the culture from one baking session to the next. Usually kept in a refrigerator.
supernatant: The same as hooch the liquid that rises to the top of a flour/water suspension that has settled.
symbiotic association: In this context, two micro-organisms that have complementary metabolic needs and products, and resistance to toxic products that each other produce. This makes their mixed culture more robust and less susceptible to disruption by a third organism that may be introduced.
temperature: Same as the conventional meaning-- the temperature of a leaven or a dough can be influenced by the environmental temperature, by the process of fermentation, and by mechanical work such as kneading. Because fermentation is more vigorous at higher temperatures and because the relative production of fermentation changes with temperature, control or accommodation to temperature is important in consistent baking.
time: The conventional meaning-- but it will need to be adjusted if temperature is not controlled.
titratable acid: The amount of acid present, regardless of the pH of the solution. The TA may be higher than expected if the buffering effect of ingredients (flour with a high ash/mineral content) is high.
top-fermenting yeast: Brewer's yeast (ale yeast, S. cerevisiae) which forms its initial fermenting mass in the top of a vessel of liquid. The progenitor of commercial bread yeasts.
Vollsauer: The third and last stage of leaven expansion in German baking. Some of this is saved to become Anstellgut, and the rest is used to prepare the dough.
Wild yeasts: Used casually to refer to the yeasts in sourdough leavens and doughs. They are not "wild" anymore when they are part of a stable culture, but the term is used to differentiate them from commercial yeasts.
yeast: Single-celled fungi that ferment sugars and produce CO2, alcohol, and other organic products. There are many species, usually differentiated by their metabolic/biochemical characteristics.
-Dan
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This page was last updated on Tue, Aug 3, 2010 at 7:53:00 PM.