Bean curd skin, also known as bean skin or bean curd skin, is a solidified film on the surface of boiled soybean milk, which can be eaten fresh or dried. It is a common food raw material in East Asia. The word bean curd skin first appeared in Li Shizhen's Compendium of Materia Medica. Li Shizhen said that when soybean milk is heated, a film appears on the surface. Take out the film and dry it to get bean curd skin. In China, bean curd is usually dried and then used as cooking material. In Japan, in addition to drying in the sun before brewing, we also like to eat freshly made bean curd, which is called "raw soup leaves". Raw bean curd can be used not only as snacks, but also as sashimi dipped in soy sauce.