Why is the dough of steamed stuffed bun white and soft?

Steamed bread is white and soft for more than two hours.

Ingredients: 50 grams of flour.

Seasoning: salt 2g.

Practice steps:

1. Yeast powder, sugar, water and salt, and stir into dough.

2. Fermented for more than two hours.

3. Knead long strips and cut into sections.

4. Put the TIC-tac-toe into four pieces, stack every two pieces, pick four heads, and finally wind them into dough.

5. Wake up in water for 20 minutes and fire 15 minutes.