2. Baking powder is a kind of compound leavening agent, which is white powder made of baking soda powder as raw material, acid substances and corn flour as fillers, also known as foaming powder and baking powder. Baking powder is a rapid starter, which is mainly used for the rapid fermentation of cereal products. When making cakes, cakes, steamed bread, steamed bread, shortbread, bread and other foods, the dosage is large.