In the seventeenth century, soy sauce was produced completely by hand and was extremely difficult work. Today, soy sauce is produced in highly automated plants using cutting-edge technology – yet the core process of natural brewing hasn’t changed for centuries.

Kikkoman Naturally Brewed Soy Sauce is made using the following process:

1. Ingredients

Kikkoman Naturally Brewed Soy Sauce is made using only four simple and carefully selected ingredients: soybeans, wheat, salt and water. Careful selection is required for these simple ingredients.

The soybeans are soaked in water for an extended period and then steamed at high temperatures. The wheat is roasted at high temperatures and then crushed by rollers to facilitate fermentation. The salt is dissolved in water.

2. Koji making

Since its foundation Kikkoman has been using its original Kikkoman Aspergillus, a type of fungus, to propagate koji mould. Koji mould is one of the most important elements in making soy sauce. It plays an essential role in fermenting the ingredients, which is the key to the taste of soy sauce!

Kikkoman’s Aspergillus is mixed with processed soybeans and wheat, and then moved to a special facility that provides the optimal environment to make Shoyu Koji from koji mould. 

3. Fermentation and aging 

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.

This process takes more than several months, making Kikkoman Soy Sauce to have its rich flavor, aroma and color which makes it unique from other soy sauce.

The normal soy sauce produced with natural fermentation process will develop alcohol from its biological process. 

However, Kikkoman have developed a special process to prevent this alcohol developing process, making it possible to have Kikkoman Soy Sauce Halal Certified*.
(*Halal Certified for the products with Halal Logo)

4. Pressing and refining for the final products

Aged moromi will be poured into a special equipment with strained through layers of fabric, folded into layers. After allowing the soy sauce to flow out of the moromi under the force of gravity, the moromi is mechanically pressed in a slow and steady process lasting for about ten hours to produce beautifully clear “raw soy sauce”.

The Kikkoman plant is filled with a sweet scent resembling fresh fruit: this is the aroma of raw soy sauce. Raw soy sauce will be left in a clarifier tank for several days to separate into its various components including oil from soybean, sediments and clarified soy sauce liquid.

The clarified soy sauce is then run through a steam pipe to heat to stabilize the quality of the soy sauce and to adjust color, flavor and aroma.

Throughout this time taking process, Kikkoman Soy Sauce have its original flavor and aroma, which is now being enjoyed throughout the world.