Dough fermentation
The kneaded dough cannot go straight into cutting and then into the oven. It is necessary to loosen this dough. Loosening of the dough for baking both rye and wheat bread is carried out biologically (using yeast and sourdough). The dough is said to be fermented.
The kneaded dough or dough (batter) is placed in a warm place. At the bakery there are special chambers for fermentation of dough and dough, in which the temperature is maintained at 30-35 ° C and the corresponding relative humidity (75-80%). Warm and humid air is necessary to maintain the normal fermentation temperature in the dough and keep the dough surface moist (moisture prevents the formation of a "crust" on the dough surface).
Fermentation is the process of decomposition of complex organic compounds into simpler ones under the action of microorganisms. There is always some heat generated during fermentation. In the dough, we are dealing with alcoholic and lactic acid fermentation.Alcoholic fermentation is caused by the presence of yeast in the dough, which is given in the form of compressed or "liquid yeast", or with sourdough. The enzyme zymase, which is found in yeast, decomposes sugar in the dough into alcohol and carbon dioxide according to the following formula:
FROM6H12ABOUT6 = 2C2H5OH + 2C02
Grape sugar Alcohol Carbon dioxide
In addition to the sugar found in flour (in high grades, about 2%, and in low grades, even higher) and yeast decomposed by zymase at the beginning of dough fermentation, under the action of flour enzymes (diastase, maltase, invertase), part of the starch is also converted into sugar. This sugar serves as new food for the yeast. During fermentation, the loss of flour dry matter will be about 1.5-2.0%.
Carbon dioxide tends to be removed from the dough, while gluten retains it. As a result, the dough increases in volume. An excess of carbon dioxide reduces the activity of the yeast. One has only to remove the gas (chipping of dough), and the activity of the yeast increases again.
The dough does not ferment immediately. The dough and dough continue to be for some time without external changes. Then, the mass begins to increase in volume and many bubbles appear on its surface. From a large number of bubbles of escaping gas, the mass seems to boil.
In addition to the decomposition of starch, protein substances change during the fermentation of the dough.
Under the action of special (proteolytic) enzymes found in yeast and flour, complex protein substances are decomposed into simpler compounds, up to amino acids.
The fat in the dough, under the action of the lipase enzyme, which is present in both flour and yeast, decomposes into simple substances - glycerin and free fatty acids.
Lactic acid fermentation is the result of the work of lactic acid bacteria, which are constant companions of yeast. These bacteria form lactic acid from grape sugar (glucose):
FROM6H12ABOUT6 = 2C3H603
Grape Dairy
sugar acid
Wheat dough in the process of fermentation is subjected to "chipping" (beating, kneading), which removes the excess of the formed carbon dioxide, and atmospheric oxygen, getting into the dough, enhances the vital activity of the yeast and improves the germination of the dough. The dough is sometimes chipped several times (up to 2-3). The quality of the dough is improving. The gluten becomes more elastic and the porosity of the bread is more uniform. If the flour is weak, do not make more than one scab.
After fermentation, the dough becomes loose and dry. Its acidity increases.
As a result of fermentation, in addition to changing the physical state of the dough, complex substances (carbohydrates, proteins, fats) are decomposed into simpler ones. This helps to improve the taste and nutritional properties of bread and to increase its digestibility by the human body.
The fermentation process of the dough can vary due to a number of factors. It can go faster and slower. Knowing the influence of individual factors on the fermentation process is essential. The conditions of production in the production of grain are very diverse and the technological process has to be built in accordance with these conditions. The following factors influence dough fermentation.
Temperature... In order for the fermentation process in the dough to proceed normally, it is necessary to knead the dough with a temperature of 28 -30 ° C. This temperature is most favorable for the activity of the yeast. But, in addition to this, as mentioned above, external favorable temperature conditions (special chambers for fermentation) create the dough.
Yeast and leaven... If you knead the dough without yeast or sourdough and then bake bread from it, then the latter will have, as we already know, the form of a cake. It will lack the normal porosity, which is of great importance for the digestibility of bread. For fermentation, both the quality and quantity of yeast and sourdough matters. The more yeast is put into the dough (but not more than 3-4% for a regular dough) and the better the quality, the more vigorous the fermentation takes place.
Flour grade... It is known that the quality of flour plays a decisive role in baking bread. In particular, the rate of fermentation of the dough depends on the quality of the flour. This is especially the case when working with wheat flour. If you make a dough from wheat flour and then wash out the starch from the latter, then an elastic elastic mass, called gluten, remains. Gluten is mainly composed of water-insoluble proteins, glutenin and gliadin. In wheat flour, the amount of raw gluten is from 25 to 40%. and in some cases even higher. Good gluten is light yellow in color and elastic. Poor quality gluten is usually gray in color and stringy.
Depending on the quality of the gluten, the dough has a different ability to retain carbon dioxide released during fermentation, as well as retain its shape during proofing and baking. This ability of flour is called
gas retention capacity.
According to its gas-holding capacity, flour is divided into strong and weak. The duration of fermentation of dough made from strong flour with good gluten increases, and from weak flour, on the contrary, decreases.
Dough made from flour with a high bran content, due to the lesser bond between the starchy particles of the flour, undergoes fermentation more quickly.
Pi fermentation of the dough also affects
gas generating ability of flour, i.e., the ability of flour to emit more or less carbon dioxide during dough fermentation. The amount of carbon dioxide emitted by the dough depends on the presence of fermentable sugars in the flour. The more of these sugars necessary for the life of yeast in the flour, the more carbon dioxide will be released from the dough. Such flour will have better gas-forming ability, as a result of which the duration of fermentation of the dough will be reduced.
Water... The rate of fermentation is influenced by the consistency (thickness) of the dough, i.e. the amount of water in the dough. With a thin (soft) dough, fermentation takes place more vigorously.
Sugar... The small amounts of sugar added to regular wheat dough speeds up the fermentation process. Sugar is known to be a nutrient material for yeast, as a result of which the activity of the yeast is enhanced.
Salt... It is used for baking bread as a flavoring material in an amount of about 1.5% by weight of flour. Depending on the type of bread, the percentage of salt may decrease or increase. With an increased percentage of salt, dough fermentation slows down.In those cases when there is a need to delay the preparation of the dough (with the sponge method of dough making), the salt intended for the dough is given into the dough and stirred with the latter. Salt, in addition to slowing down fermentation, binds and strengthens the dough.
Regulation of the technological process (fermentation of dough and dough) is carried out mainly by changing the temperature if the amount of yeast. As a rule, in cases where it is required to slow down the fermentation process, it is better to lower the temperature, while accelerating fermentation, increase the amount of yeast. It is necessary to increase the temperature very carefully, as high temperatures impair the quality of the bread (favorable conditions are created for unwanted microorganisms).
To ensure production with the required amount of ready-made dough, the required number of bowls under the fermentation of the dough is calculated according to the following formula:
X = AB,
where X is the number of bowls,
A - the number of bowls of dough passed by the ovens in 1 hour
B is the duration of fermentation of the dough, expressed in an hour.
Suppose production requires 15 bowls of dough per hour and the fermentation time is 2 hours. In this case, it will be necessary to have a bowl under the fermentation of the dough:
15*2 = 30
The same calculation will be done for dough.
The required number of bowls under the fermentation of the leaven and saccharification (cooling) of the infusion can be calculated by the formula:
X = AB / K
where X is the number of bowls,
A is the number of bowls of dough passed by the ovens per hour, B is the duration of fermentation of the leaven and saccharification (cooling) of the brew, expressed in an hour.,
K — the number of portions of the leaven (brew) used for the dough (dough).
If three bowls of dough are prepared from each bowl of sourdough, then when the production consumes 15 bowls of dough per hour, the number of bowls under fermentation of the leaven will be:
15*2/3=10
From the book of P. M. Plotnikov, M. F. Kolesnikov - 350 varieties of bakery products - 1940
