It takes about 7 days for fermented fermented bean curd to grow hair.

Bean curd needs to be fermented during the production process, and during the fermentation process, a fungus called mold will grow. After the bean curd is fermented, it takes about 7 days to grow hair. Hair is the result of the growth of mold, forming a layer of white or gray fluffy objects on the surface of fermented bean curd. Mold plays a role in fermentation and seasoning, giving fermented fermented food its special flavor and texture.