The most important thing to use yeast dough is to master the proportion. Too much yeast will make dough sour, and too little yeast will not ferment, so the proportion is very important. Steamed bread for three or four people, two or three kilograms of flour and yeast the size of a matchbox are enough. I don't know what kind of yeast you have there. We are all dry yeasts, that is, a piece of dough fermented last time. Let it dry for a few days and it can be used repeatedly. Soak dry yeast in warm water for a while to soften it and crush it. Pour yeast water into flour. In order to neutralize the sourness of yeast, you can put some alkaline water or white sugar water. The dough is raised for about an hour after it is formed. According to different temperatures, some hot water can be put under the basin in winter to accelerate fermentation. When there are small bubbles on the surface of the dough, open the dough and install air holes, which is basically enough.