Production of Koji, Mixing and Aging
Kikkoman’s Aspergillus
Since its foundation, Kikkoman has been using its original Kikkoman Aspergillus, a type of fungus, to propagate koji mold. Koji mold is one of the most important elements in making soy sauce, and plays an essential role in fermenting the ingredients: this activity is the key to the taste of soy sauce.
Production of Shoyu Koji
Kikkoman’s Aspergillus is mixed with processed soybeans and wheat, and then moved to a facility that provides the optimal environment for propagating koji mold. This three-day process results in the production of shoyu koji—the essential base of soy sauce.
Mixing
The mixing process starts from here: the shoyu koji is moved to a tank and mixed with the salt-and-water solution. This mixture is called moromi, a kind of mash, which is then fermented and aged in the tank.
Fermentation and Aging of Moromi
Moromi is aged for several months. Various actions take place in the tank, including lactic acid fermentation, alcoholic fermentation and organic acid fermentation, all of which impart to the moromi the rich flavor, aroma and color that are unique to soy sauce.
