Soy sauce is a dark, salty, deeply savoury liquid seasoning brewed by fermenting soybeans and wheat with mould, salt and brine. Thin and translucent reddish-brown to almost black, it carries a powerful umami punch alongside its salt, with malty, meaty and faintly sweet aromas. One of the oldest condiments still in daily use, it is the backbone of East and Southeast Asian cooking.