Making Soy Sauce

In the seventeenth century, soy sauce was produced completely by hand, and as this picture shows, it was extremely difficult work. Today, soy sauce is produced in highly automated plants using cutting-edge technology—yet the core brewing process has not changed for centuries. We make what we call naturally brewed soy sauce using the traditional Japanese process, honjozo, described below.


Using the traditional Japanese process, honjozo, we make what we consider naturally brewed soy sauce. Our naturally brewed soy sauce is made using only four basic ingredients: soybeans, wheat, salt and water. Careful selection is required for these simple ingredients, as they directly influence the flavor and aroma of the soy sauce.

Role of Soybeans


The unique characteristics of soy sauce originate primarily from the proteins contained in soybeans. Soybeans are first soaked in water over an extended period, and then steamed at high temperatures.

Role of Wheat


Carbohydrates contained in wheat are the components that give soy sauce its fine aroma; wheat also adds sweetness to the soy sauce. Wheat is roasted at high temperatures, and then crushed by rollers to facilitate fermentation.

Roles of Salt and Water


Salt is dissolved in water, and this brine is used to control the propagation of bacteria during the fermentation process and act as a preservative.

Kikkoman 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.