It is one of the oldest condiments in the world and is made through the fermentation of soybeans with a type of Japanese mushroom. Soy sauce is based on salt, wheat and soybeans and although there are no significant differences in the production processes, it is true that sauces fermented in different regions have a distinctive taste.
The climate where the fermentation takes place affects the flavor and even the aroma of the soy sauce. Although with the new technologies it is possible to produce the same soy sauce anywhere in the world thanks to the control of microorganisms (yeasts or lactic acid bacteria) in stainless steel tanks. Japanese cuisine is governed by the principles of health and quality, which are essential for making a good soy sauce.
The most traditional fermentation processes can last up to three years, because they do not use heating formulas that would shorten this period. A laborious process that has its reward, since the fragrance of long-term fermentation at low temperatures gives it an intense and characteristic aroma.
Writing: gastronomia.com