After the dough is separated, some carbon dioxide is lost, and it takes 15 minutes for intermediate fermentation to regenerate new gas and make the dough soft again. Usually the baking powder we use is a mixture of acid salt and baking soda, and starch is added as a filler to maintain chemical stability. In pastry making, it is not yeast fermentation, but acid-base neutralization reaction that produces a lot of carbon dioxide after adding water. When baking bread, a large amount of carbon dioxide gas overflows, which leads to honeycomb pores in bread and makes bread fluffy.

Bread can be made by primary fermentation (direct dough method) and secondary fermentation (yeast and dough method).

The technological process of secondary fermentation is primary stirring → fermentation → secondary stirring → continuous fermentation.

Fermentation → molding → baking.