Steamed bread, also known as "steamed bread" in some places in the north, is also known as "solid bag" in Wenzhou, Zhejiang Province. Other places are directly called "steamed bread" or "light package". Generally, the semi-circular appearance is flat, and the red seal is printed on the top of each festival. This kind of product is based on a single flour or several kinds of flour as the main ingredient. Except for the starter, there are usually a small amount or no other auxiliary ingredients (auxiliary materials are added to produce colorful steamed bread), which are processed by the processes of mixing flour, fermentation and steaming

Steamed bread contains yeast, which is divided into fresh yeast and dry yeast. It is an edible and nutritious single-cell microorganism. In nutrition, it is called "inexhaustible nutrition source". In addition to protein, carbohydrate and lipid, yeast is rich in many vitamins, minerals and enzymes.

It has been proved that the protein content of 1 kg dry yeast is equivalent to the protein content of 5 kg rice, 2 kg soybean or 2.5 kg pork. Therefore, the nutritional composition of steamed bread and bread is 3-4 times higher than that of pancakes and noodles, and the protein is nearly 2 times higher.

The fermented yeast is also a strong antioxidant, which can protect the liver and has a certain detoxification effect. Selenium, chromium and other minerals in yeast can resist aging, anti-tumor, prevent arteriosclerosis, and improve human immunity. After fermentation, phytic acid in flour which affects the absorption of calcium, magnesium, iron and other elements can be decomposed, so as to improve the absorption and utilization of these nutrients by human body.

Steamed bread is made of flour by fermentation. The main nutrient is carbohydrate, which is the basic food for people to supplement energy.

It is suitable for people and can be eaten by ordinary people.

The steamed bread is made of flour by fermentation, which is easier to digest and absorb. People with diarrhea caused by too much stomach acid, distention and indigestion will feel comfortable and reduce symptoms when eating baked bread.