According to the national standard GB/T 18186-2000 for brewed soy sauce, soy sauce fermentation processes can be divided into two categories:
High-salt liquid-state fermented soy sauce
Made from soybeans and/or defatted soybeans, wheat and/or wheat bran, the mixture is steamed, fermented with Aspergillus oryzae to form a koji (fermentation starter), then mixed with brine to form a thin mash, which is then fermented.
The fermentation temperature is relatively low, and the fermentation time is long, ranging from several months to up to a year. This type of soy sauce has a light color, high quality, rich soy and ester aroma, good taste, and a high price.
Low-salt solid-state fermented soy sauce
Made from defatted soybeans and wheat bran, the mixture is steamed, fermented with Aspergillus oryzae to form a solid mash, then fermented.
The fermentation temperature is high, and the fermentation time is short, generally 20-30 days. The formation rates of amino acids, aldehydes, and esters are low, the taste is not as good as high-salt liquid-state soy sauce, the color is light, and the price is relatively low.
High-salt liquid-state fermentation is the mainstream fermentation method, and high-salt liquid-state soy sauce is preferred.
