2. Why is dough mixing an indispensable key step in making bread?
The first process of making bread is "kneading dough", that is, mixing flour, yeast, water and other auxiliary materials into dough. Mixing is the key step in making bread.
(1) All raw materials are fully mixed by stirring to form a completely uniform mixture.
(2) Mixing can make flour fully absorb water and accelerate the formation of gluten. When flour is put together with water and other raw materials, water wets the surface of flour particles and forms a tough film. If it is not stirred, it is difficult for the central part of flour particles to be wetted by water, and it is difficult to form gluten. The more evenly water is distributed on the surface of flour particles, the faster it enters the interior of the particles. Therefore, by stirring, water can quickly cover the surface of flour particles, so that all flour can absorb enough water in a short time and accelerate the formation of gluten.
(3) Stirring time will affect the quality of dough: if the stirring posture is normal and the stirring time is moderate, the gluten formed can reach the best state, and the dough has certain elasticity and ductility, which lays a good foundation for making soft and delicious bread. If the stirring is insufficient, the gluten can't fully expand, has no good elasticity and ductility, can't retain the carbon dioxide produced in the fermentation process, and can't soften the gluten, so the bread made is small in volume and rough in internal structure. If the mixing is excessive, the dough will be too wet and sticky, and the molding operation will be very difficult. After the dough is rounded, it will not stand upright, but will flow around. Baked bread can't keep the expanding gas, which leads to too small volume, large holes inside, rough structure and poor quality.
3. How to judge whether the dough stirring is moderate is generally determined by the senses. Properly stirred dough can be stretched into cellophane-like film with both hands, and the whole film is evenly distributed and smooth. Put the dough into the fermentation tank and touch the top with your hands, but it will not stick to your hands when you leave the dough, and the fingerprints on the surface of the dough will soon disappear.
4. What are the factors that affect dough fermentation? To make bread within the specified time, we must master the fermentation speed of bread. Generally speaking, there are five factors that affect the bread fermentation speed: the quality and dosage of yeast, indoor temperature, water temperature, the addition of salt and sugar, and the moisture content of dough.
(1) yeast quality and dosage: more yeast is used, and the fermentation speed is fast; The amount of yeast is small, and the fermentation speed is slow. The quality of yeast also has a great influence on fermentation. Yeast stored improperly or for too long has dark color, low fermentation power and slow fermentation speed.
(2) Indoor temperature: the indoor temperature of dough fermentation place is high and the fermentation speed is fast; The indoor temperature is low and the fermentation speed is slow.
(3) Water temperature: At normal temperature, the dough is kneaded with warm water of about 40℃, and the dough temperature is about 27℃, which is most suitable for yeast propagation. If the water temperature is too high, the yeast will be easily scalded to death; If the water temperature is too low, yeast will reproduce slowly. On a hot day, the room temperature is relatively high. In order to avoid fermentation too fast, cold water and flour are used.
(4) Addition amount of salt and sugar: a small amount of salt is beneficial to the growth and development of yeast, while too much salt will inhibit yeast reproduction. Generally speaking, adding 2 ~ 3 grams of salt to 500 grams of flour is beneficial to fermentation. Sugar provides nutrition for yeast reproduction, accounting for about 5% of the total dough, which is beneficial to yeast growth and accelerates yeast reproduction; Too high sugar content in dough is not conducive to fermentation. Therefore, for some varieties with heavy sugar and heavy oil, the amount of yeast should be appropriately increased. For example, in the formula of clear sugar bread, 500 grams of standard flour, 60 grams of white sugar, 40 grams of maltose, and the amount of fresh yeast is 10 gram; In fruit toast bread, there are 500 grams of flour, 0/50 grams of sugar/kloc-and 90 grams of candied fruit, and the sugar content is more than twice that of clear sugar bread, so the amount of fresh yeast is more, reaching 20 grams (the latter two cases are all fermented at one time).
(5) Water content of dough: the dough with high water content is soft and the fermentation speed is fast; Dough with low water content is hard and slow in fermentation.
5. What are the methods of dough fermentation? The methods of dough fermentation include primary fermentation, secondary fermentation, intermediate seed fermentation and old fermentation.
One-time fermentation method: refers to the method of mixing all raw materials and yeast liquid at one time, mixing powder and fermenting until the dough is mature. Its advantages are short fermentation time, about 2 hours; Disadvantages are high yeast consumption, high cost, difficult control of fermentation time, rough products and easy to produce large cavities.
Secondary fermentation method: refers to preparing dough twice. For 1 time, 50% ~ 70% of all flour and all yeast are added with appropriate amount of water to make dough. After the fermentation is mature, the remaining raw materials are added for the second kneading fermentation. Its advantages are complete fermentation and good product quality; Yeast consumption is only 1/2 of one fermentation. The disadvantage is that it needs to be mixed and stirred twice, which consumes a lot of manpower and the whole fermentation time is long.
Medium-seed method: also known as Japanese medium-seed method, its basic principle is similar to that of secondary fermentation, but its specific practices are somewhat different. 1 time, mix 50% of all flour, all yeast, yeast nutrients and appropriate amount of water into dough, add the remaining raw materials after fermentation, and mix the dough for the second time. His 1 fermentation time was longer than the second fermentation time, and the second fermentation time was shorter. This product has the characteristics of thin skin, good color, large volume, fine internal pores, elasticity, softness and delicious taste.
Old fermentation method: also known as old dough method, it is to add flour, water and other auxiliary materials to the fermented dough left over from the last bread making, and then ferment it into dough. After the fermentation is mature, add an appropriate amount of caustic soda to neutralize the acidity of the dough, and then slice it. The advantage of this method is low cost, and no new yeast will be added after the yeast is put into use once. The disadvantage is that the mixed bacteria in the fermented dough are easy to reproduce and the dough has high acidity. But in some areas, it is difficult to buy fresh yeast or active dry yeast, so the old fermentation method might as well try.
6. What is water fermentation? When you need to make bread in a short time, you can use water fermentation. The specific method is: leave a part of flour as hand flour, and the remaining flour, together with auxiliary materials and yeast, form a hard dough. Put the fermented dough into a bucket filled with warm water and put it in a greenhouse for fermentation. At first, the dough sank to the bottom of the barrel. After a period of time, the dough fermented and floated on the water surface, indicating that it can be used for molding when it is mature.
7. How to master the amount of water added in the first 1 fermentation of bread fermented twice?
Using secondary fermentation, the dough fermented for the first time 1 time should be softened, and the amount of water added varies with varieties, with sweet bread 60% ~ 70% and staple bread 70% ~ 75%. Too much water will make the dough sticky and difficult to operate; If too little water is added, the fermentation will be slow.
8. What is the key to making fermented dough? The preparation of dough is an important link in making bread, and it must not be regarded as a simple mixture of flour and various accessories. In order to make the prepared dough meet the pre-conceived requirements, we must pay attention to the following points.
(1) Feed the dough in the correct order, and the feeding order must depend on the fermentation method of the dough.
(2) Control water temperature and water addition. Mastering the water temperature is one of the important means to control the dough approaching the fermentation temperature of yeast. The fermentation temperature of dough is generally required to be 28 ~ 30℃. In order to control the dough temperature within this temperature range, it is generally adjusted by increasing or decreasing the water temperature. The temperature of adding water depends on factors such as room temperature and flour temperature. In spring, the room temperature is about 20℃ and the water temperature is 35 ~ 40℃. When the room temperature is above 30℃ in summer, the water temperature is generally 13 ~ 15℃. In order to correctly determine the water temperature, it can be determined according to the following formula:
Formula 1: WL = ideal dough temperature × 3- (room temperature+flour temperature+dough raising temperature)
Where W 1 is 1 water temperature during kneading.
Formula 2: W2 = ideal dough temperature × 4- (room temperature+flour temperature+raised temperature during kneading)+dough temperature after the first fermentation.
Where W2 is the water temperature in the second kneading process.
Generally, the amount of water added is 45% ~ 60% of flour, depending on the product requirements and the contents of sugar, salt, milk and eggs in the formula. If the water content of flour exceeds the standard value, add less water as appropriate, otherwise add more water. Add more water to flour with high gluten content. Salt will reduce the water absorption of flour. Adding 2% salt will reduce its water absorption by 3%. Sugar can also reduce the water absorption of flour. For every 5% increase in sugar, the water absorption will decrease 1%. Milk and milk powder: Fresh milk contains 87.2% moisture. If there is 100 ml fresh milk in the formula, add about 80 ml less water. If the formula is milk powder, the water addition will increase. Every time milk powder increases 1%, the water content of dough will increase by about 1%. Eggs: Fresh egg liquid contains 70% water, so if there are eggs in the formula, reduce the amount of water added. For every increase of 100g of egg liquid, the amount of water added will be reduced by about 70ml.
(3) Master the method and time of surface fusion. Dough preparation probably goes through four stages: dispersing and mixing all ingredients evenly; Let the flour fully absorb water to form gluten; Combine small pieces of gluten into large pieces of gluten; Promote water infiltration into protein, and make dough elastic, malleable and tough. Generally speaking, 2 kilograms of bread can be made by hand. Determine the hand-made method according to the dough making stage. Stir first, mix the ingredients by hand according to the feeding order, then spread the noodles on the bed board and let it stand for 3 ~ 5 minutes. Let the flour fully absorb water to form gluten. At this time, you can add oil, fold, roll, stir and knead, so that the ingredients in the dough are evenly mixed and a large amount of water penetrates into the protein. Forming dough with elasticity, ductility and toughness. From the appearance, the dough surface is shiny and the dough is finished. The stirring time of the whole powder is about 10 ~ 14 minutes.
9. What is the optimum temperature for dough fermentation?
The optimum temperature for dough fermentation is 25 ~ 28℃ (which is the optimum temperature for yeast propagation). Propagation of asexual buds of yeast strains. In the process of reproduction, the empty cells of the mother nucleus produce a tubule called the intermediate sulcus. This tube rises to the surface of the cell, producing a protrusion through the cell wall, that is, a bud mark. Bud marks gradually grow up and fill the cytoplasm and nucleus of mother cells. When the nucleus grows as big as the mother cell, the mother cell nucleus is divided into two parts, and the two cells are completely located. The centrosome of the cell is far away, at this time, the mother cell and daughter cell have been completely separated, resulting in new bud marks respectively. When the temperature is 4℃, the yeast will reproduce for 20 hours. With the increase of temperature, the generation cycle is shortened. When the temperature is 23℃, the generation cycle of yeast is only 6 hours. At 60℃, the yeast died.
When making dough, it is inevitable to mix mixed bacteria such as lactic acid bacteria and acetic acid bacteria. The optimum reproductive temperature of lactic acid bacteria is 35℃. If the fermentation temperature is higher than 30℃, lactic acid bacteria and acetic acid bacteria will multiply, which will inhibit the reproduction of yeast and make the dough sour, so the dough fermentation temperature should be controlled at about 25 ~ 28℃.
10. Why should the dough be pressed when it is fermented?
Pressing dough, also called rolling, is an essential process in dough fermentation. Yeast will release heat in the process of reproduction, which will increase the temperature of dough. Because the surface temperature of dough is easy to emit, the internal temperature of dough is higher than the surface temperature. The distribution of sugar, salt and gas in the dough is more uniform by adjusting the internal and external position and temperature of the dough through extrusion. At the same time, the pressed dough can also exchange some carbon dioxide, alcohol and fresh air with the outside world, creating good conditions for the vigorous growth and reproduction of yeast. In addition, the dough pressing can temporarily retract the gluten in a tense state, maintain the extensibility and elasticity of the gluten, and make the bread not easy to collapse and shrink.
1 1. How far can the dough be fermented before it can be pressed?
Grasping the timing of dough pressing has a great influence on the quality of bread. The way to check whether the dough in fermentation has reached the dough pressing time is to dip your finger in a little water, insert it into the dough and pull it out quickly. If the dough does not return to its original state and the part where the finger is inserted shrinks, you can press the dough. The method of pressing dough is: push the dough in the middle with both hands, and then fold the dough squeezed out from both sides to the middle and press it in the middle. Turn the pressure back and forth, left and right in turn, and finally turn the whole dough over. After the dough is pressed, continue to ferment in the warm box, and press the dough for 2 ~ 3 times during the whole fermentation process.
12. How to judge that the dough has been fermented and matured? Signs that lead to dough fermentation maturity are: the top of dough bulges, but it feels dry. When you lift it with your hands, the dough is naturally elongated. Once you let go, it will slowly retract.
(2) There are many air holes in the dough.
(3) the aroma of wine.
If the dough is made slowly, the surface is smooth, it is wet and sticky when touched by hand, and it will break when pulled, which means that there is something wrong with dough fermentation.