1. The main reason for the nutritional loss of steamed bread is adding alkali to the fermented dough. Vitamin B 1 in flour is relatively stable in acidic environment, but it is easily destroyed in alkaline environment. If too much alkali is added or alkaline leavening agents such as soda are used to make steamed bread, most of the vitamin B 1 in the dough will be destroyed.

2. Proper addition of alkali can make the dough sweet and sour. At the same time, when heating, put the steamer in a big fire atmosphere and steam it once, and the steamed bread will be soft, white and delicious.

3. When the temperature in the dough reaches 33 degrees Celsius, acetic acid bacteria multiply with the fermentation of yeast, and secrete oxidase, which oxidizes the dilute alcohol in the dough into acetic acid and water, making the dough have a strong sour taste and become more soft and rotten. The longer the fermentation time, the stronger the sourness of dough, so alkali must be added to neutralize the sourness.

4. The correct alkali mixing should be flexibly controlled according to the size, tenderness, temperature, fermentation time, the use of yeast and the requirements of products. 3.7-4.3g of alkali is added to 0.5kg of fermented flour for neutralization, and the steamed bread has high vitamin preservation rate, good taste and easy digestion.