Analysis of common problems in steamed bread

（1） What are the causes of steamed bread blistering

1. And in front of, yeast or old flour is not well mixed with flour evenly.

2. When mixing, the dough is not kneaded in place and the gluten network is not fully formed, which leads to the bad air holding property of the dough.

3. Wake up, wake up box humidity is too large, resulting in condensation phenomenon.

4. Wake up time is too short, in the process of steaming due to intense gas production.

5. When the new wheat is not used at the later ripening stage, the enzyme activity is too high and it is easy to blister.

6. The enzyme activity of old wheat is too low and easy to blister.

（2）Steamed bread shrinks to death

Steamed bread shrinkage refers to the phenomenon that steamed bread shrinks after the fire is turned off in the process of steaming. It is commonly known as "ghost kneading steamed bread". There are many reasons for this phenomenon. We think the main reason is that the pressure inside and outside the steamed bread is not balanced after the fire is turned off.

1. In the fermentation process of steamed bread, yeast produces carbon dioxide gas, but the steamed bread itself can't keep these gases completely. Part of the gas has to escape to the outside of the steamed bread. When the gas production rate is greater than the escape rate, the steamed bread can start slowly. During the steaming process, there is an atmospheric pressure inside and outside the steamer, and the air pressure inside the steamed bread should also maintain an atmospheric pressure, according to PV = NRT According to the law, the volume of steamed bread should expand, and the carbon dioxide in the body of steamed bread should also overflow, and water vapor and water vapor should be produced. In the process of steamed bread, most of the carbon dioxide gas is gradually replaced by water vapor and water vapor. In fact, the gas in steamed bread becomes a mixture of water vapor, water vapor, carbon dioxide gas and air. When the heating is stopped, the temperature in steamed bread decreases, Part of the steam and water vapor condense into liquid water. When the air permeability of the steamed bread skin is not very good, there is no time to supplement the external gas. Due to the volume loss caused by the condensation of steam and water vapor, the air pressure drops sharply, which is lower than an atmospheric pressure of the outside world. Under the effect of this pressure difference, the steamed bread begins to contract. When the air permeability of the steamed bread skin is good or there is a defect in the skin, the steamed bread will collapse Flour with high gluten strength is easy to shrink because of its better network structure and poor air permeability. 

2. When the gluten network of flour is not fully formed, it is easy to shrink.

3. Unripe flour and new wheat flour are easy to shrink.

4. Flour gluten is too weak, gas holding capacity is not good, also easy to shrink.

（3）Separation of skin and core of steamed bread

1. After some steamed bread comes out of the pot, the phenomenon of skin and heart separation is generally caused by excessive fermentation, because the quality of protein in steamed bread flour is not very good. When the fermentation is excessive, the protein network becomes weak and expands violently when entering the pot. All kinds of gases inside the steamed bread gather together, and the protein network can not support. The separation phenomenon will occur in the cortex of steamed bread to control the fermentation process To solve this problem.

2. The storage time of wheat is too long.

3. The elongation ratio is not suitable and the elongation is too small.

（4） Reasons for rough internal structure of steamed bread

1. Excessive fermentation.

2. The activity of enzymes in flour was low.

3. The exhaust of steamed bread is incomplete and uneven.

4. The intrinsic quality of raw powder is poor.

（5） Cracking of steamed bread epidermis

1. Less water is added.

2. The water temperature is low and the room is dry.

3. The humidity inside the hair box is low.

4. The molding time is too long.

（6） Causes of steamed bread sticking to teeth and hands

1. The enzyme activity of sprout wheat and new wheat was too high.

2. The steaming time is short.

3. The flour itself returns water, easy to appear false water absorption.

4. The content of damaged starch in flour is too high.

5. The gluten content and strength are too low.

（7） Surface collapse of steamed bread

1. When forming, the foaming is completely discharged, and the dough is not uniform inside and outside.

2. Dough wakes up too fast.

3. If the steam is not strong, it can be quickly steamed.

4. Yeast inactivation or insufficient activity.

5. The quality of the flour is too poor and the strength is not enough.

（8） The finished product is easy to be aged, hard and dross

1. The quality of flour was poor and the activity of a-amylase was too low.

2. When the steamed bread is formed, the water content is insufficient, and the appropriate amount of water can be added.

3. If the mixing is insufficient, the gluten can be fully stirred to form a network.

4. In case of insufficient fermentation, yeast with strong fermentation power can be selected.

Common problems and solutions of steamed bread making

1. The surface is easy to collapse

① When forming, there are faults. When forming, pay attention to discharge bubbles to make the dough uniform inside and outside.

② If the dough wakes up too fast, the fermentation temperature of dough can be reduced.

③ If the steam is not strong, it can be quickly steamed.

④ If yeast has insufficient stamina, Angel yeast can be used.

⑤ If the quality of flour is poor and the gluten is not enough, medium gluten flour can be used.

2. Steamed bread is too puffy

① Too long wake-up time can shorten the wake-up time.

② If gluten is not enough, medium gluten flour with strong gluten can be used.

③ If the amount of yeast is too large, the amount of yeast can be reduced appropriately.

3. Steamed bread is not white on the surface

① If the quality of flour is poor, medium gluten flour and Angel yeast can be used

② Molding is not good, molding to keep the dough surface smooth, can be appropriate pressure surface, sprinkle some dry powder

4. The epidermis is dull, wrinkled or cracked

① If the speed of awakening is too fast, the fermentation temperature can be reduced.

② Steam shortage, can be used to steam.

③ The steamed bread is rough and smooth. It can be calendered 3-4 times with a noodle press.

④ Because of the low gluten content, medium gluten flour and Angel yeast can be used instead.

5. The finished product is easy to be aged, hard and dross

① If the quality of flour is poor, medium gluten flour and Angel yeast can be used instead.

② When the steamed bread is formed, the water is not enough, so appropriate amount of water can be used.

③ If the mixing is insufficient, the gluten can be fully stirred to form a network.

④ In case of insufficient fermentation, Angel Yeast with strong fermentation power can be selected.

6. The internal organization is rough

① If the quality of flour is poor, medium gluten flour and Angel yeast can be used instead.

② Dough fermentation time is too long, high temperature, can shorten the fermentation time, reduce the fermentation temperature.

③ When mixing, there is too much hand powder, but less hand powder.

7. Slow fermentation

① The amount of yeast should be increased and the yeast should be preserved at low temperature.