Steamed steamed bread can't be used if the cover smells. It has gone bad, so steamed buns are often steamed with cover cloth. Then it must be washed out immediately after steaming and dried in the sun to prevent moisture from loving bacteria. Moldy is caused by bacteria. Under normal circumstances, just wash it with detergent. The key is to dry in the sun regularly after washing. Air-dried cloth smells easily. Steamer originated in Han Dynasty, which is a wonderful flower of Han diet culture. Among them, the steamer is famous for its original flavor, non-backflow of soda water, good color, fragrance and taste. As an ancient Han handicraft. Steamers are mainly divided into those with green skins and those without green skins. At present, green husk steamer is rare, mainly because of its low price and poor quality, which was common in the early 1980 s.