Yellow soybean paste is a fermented paste made from yellow soybeans, salt, and water; wheat flour, though not formerly used, is often used as an additional ingredient in the modern day, and potassium sorbate may also be used as a preservative. Yellow soybean paste is produced in China and is used primarily in Beijing cuisine and other cuisines of northern China.
Despite its name, the paste is not yellow in color; it ranges from light to dark brown, or even black. The name comes from the fact that it is made from yellow soybeans, called huángdòu (黄豆) in Chinese. Although it would seem that the complete name in Chinese should be huángdòu jiàng (黄豆酱; literally "yellow soybean paste"), the word dòu (豆) is generally not used when referring to this paste.
Yellow soybean paste is used most notably in the noodle dish called zhajiang mian. Though outside Beijing sweet bean sauce or hoisin sauce are often used as substitutes. In this dish, the yellow soybean paste is fried together with ground pork, then poured over the top of thick wheat flour noodles. Unlike sweet bean sauce, yellow soybean paste is salty rather than sweet.