Soybean juice and soybean milk are two different drinks, soybean juice is a series of fermentation processes with mung beans as raw materials, gray-green color taste sour with bitter, there is a stench; soybean milk is a series of processes such as soaking water with soybeans made of milky-white liquid flavor, rich in nutrients and easy to absorb.

Soybean juice is a unique traditional snack in Beijing, with a history of 300 years according to written records. Bean juice is made from mung beans, the starch filtered out of the production of vermicelli and other food products after the remaining residue of fermentation produced, with stomach, detoxification, fire effects. Bean juice has a long history and is said to have flourished in Beijing as early as the Liao and Song dynasties.