The answer is simple: because the flour whitening agent is added to the dry yeast (which is mandatory by the state), and the steamed bread made from old yeast may not be added. Surface tenderness is caused by emulsifier in dry yeast.

Actually, none of this is complicated. If you master the added amount, you will also make them beautiful. On the contrary, it must not be added blindly, or something will happen.

I am more optimistic about the quality of steamed bread, that is, whether it can reach more than three times of the original dough.

I suggest you eat it yourself, forget it, it's not worth wasting your mind; If it's takeout, call me. After all, a commodity sells a piece of leather.