Soy sauce
Soy sauce is a condiment
A condiment is an edible substance, such as sauce or seasoning, added to food to impart a particular flavor, enhance its flavor, or in some cultures, to complement the dish. Many condiments are available packaged in single-serving sachets , like mustard or ketchup, particularly when supplied with...

 produced by fermenting
Fermentation (food)
Fermentation in food processing typically is the conversion of carbohydrates to alcohols and carbon dioxide or organic acids using yeasts, bacteria, or a combination thereof, under anaerobic conditions. Fermentation in simple terms is the chemical conversion of sugars into ethanol...

The soybean or soya bean is a species of legume native to East Asia, widely grown for its edible bean which has numerous uses...

s with Aspergillus oryzae
Aspergillus oryzae
Aspergillus oryzae is a filamentous fungus . It is used in Chinese and Japanese cuisine to ferment soybeans. It is also used to saccharify rice, other grains, and potatoes in the making of alcoholic beverages such as huangjiu, sake, and shōchū...

 or Aspergillus sojae
Aspergillus sojae
Aspergillus sojae is a mold species in the genus Aspergillus.In Japan it is used to make the ferment of soy sauce, the mirin and other lacto-fermented condiments like tsukemono...

 molds, along with water and salt. After the fermentation, which yields fermented soybean paste, the paste is pressed, and two substances are obtained: a liquid, which is the soy sauce, and a cake of (wheat and) soy residue, the latter being usually reused as animal feed. Most commonly, a grain
Cereals are grasses cultivated for the edible components of their grain , composed of the endosperm, germ, and bran...

 is used together with the soybeans in the fermentation process, but not always.