Simply Obsessed:produced by Carillon LLC

Reproducing Shogun-Era Shoyu in Kozaki Fermentation Town

Chiba’s Choshi and Noda are cities well-known as shoyu producers because their weather and its ingredients are perfectly suited. By the way, the famous Kikkoman company, which took shoyu global, is headquartered in Noda. In that prefecture, Fujihan is located just between Choshi and Noda and these three cities are connected by the Tonegawa river. Not only shoyu but also other food produced in the prolific grounds in Chiba were carried by ship to Edo by the river in the shogun era. Due to this advantageous water transportation method, Kozaki also had many shoyu brewhouses. Compared to those brewhouses, Fujihan brewery was comparatively new. Today, it’s one of the oldest surviving shoyu brewhouses in this region.

Let’s take a look back through time. Until the early 17th century, light-colored (usukuchi) shoyu was transported to the eastern Kanto region for processing by ship from western cities like Osaka and Hyogo, and from there it was shipped out to Edo. In the late 17th century, dark-colored (koikuchi) shoyu started to be manufactured in Chiba. Back then, shoyu’s ingredients, namely wheat and soybeans, were produced abundantly in this region, helping Chiba to become a center of shoyu production. Once dark-colored shoyu was made, Edo consumers no longer had to depend on the light-colored shoyu carried all the way from the west. It’s the same type that we enjoy today.

In the 19th century, dark-colored shoyu became popular in Edo, and that market share gradually increased across Kanto. A lot of popular Japanese food was developed during this period. While sushi, soba noodles, unagi grilled eel over rice, etc., were all conceived of and catching people’s attention, shoyu was becoming a must-have item.


Despite such established history, not many Japanese people know what makes shoyu. When I asked my friends if they knew its ingredients, none of them knew the answer! Everybody knows of shoyu, and now it has a global presence, yet people don’t know what it’s made of.

Shoyu is made of shoyu koji, which is a mixture of koji, wheat, soybeans and salt water. Smashed, roasted wheat and boiled (or steamed) soybeans are mixed together, and then seed malt is added. This is called shoyu koji. When you add salt water and ferment it, it becomes moromi, one step before becoming complete shoyu. Moromi is a thick, brown, sloppy liquid that contains a lot of fiber from the beans and wheat. The taste and aroma are exactly the same as those of shoyu. You can eat it as it is. When you brew moromi for two years in a wooden barrel, it’s ready to become shoyu. The fermented moromi is squeezed, percolated, heated and bottled to become the final product. As the fermentation takes place, the moromi emits the excellent aroma of the shoyu it will become.

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