Alkali, also known as baking soda, with the molecular formula of nahco3, is an acid salt, which is decomposed by heat to produce carbon dioxide, which is heavier than air, so the gas expands horizontally to both sides.

Excessive consumption of flour will increase alkalinity and ph value, and the inside and outside color of steamed bread will turn yellow, which will destroy the tissue and make the shape bad.

Add an appropriate amount of alkali before steaming steamed bread, sober up for a while, taste it without sour taste, and then steam it.

Steam a few steamed buns. It won't be like this after experience.

Ps: You can also use baking powder. The dose is marked on it.