A common ingredient in Japanese cuisine, miso is a fermented soybean paste that comes in a wide variety of flavors, colors, textures, and aromas. It is used in dressings, for pickling, as a spread for grilled foods, and as a base for soups. According to chef Nobu Matsuhisa, all miso falls under three basic categories: komemiso, made with rice and soybeans; mugimiso, made from barley or rye and soybeans; and mamemiso, made from soybeans alone.
Miso is produced by crushing boiled soybeans and injecting them with a yeastlike mold cultivated with a barley, soybean, or rice base. The mixture is then allowed to mature six months to three years. The darker the miso, the longer it has been fermented. Darker miso, which is saltier and stronger, is used in more robust-flavored dishes. The lighter-colored varieties are generally used in more delicate soups and dressings.