Located near the Ibogawa river that flows through Tatsuno City in Hyogo Prefecture and on into the Seto Inland Sea, Suehiro Shoyu has been brewing usukuchi (light colored) soy sauce using traditional methods since 1879. Tatsuno City is the birthplace of usukuchi soy sauce, where it has been brewed since the 1600s.
Usukuchi shoyu is a bit different from 'regular' shoyu, which is known as koikuchi (dark) shoyu. Compared to koikuchi shoyu, usukuchi is lighter in color, but still has wonderful flavor and aroma. Usukuchi is also slightly saltier. Usukuchi shoyu is used by chefs when they want to add soy sauce flavor without adding much color. Indeed, a well-made usukuchi shoyu like Suehiro's has an almost rose-colored hue.
Other differences between usukuchi and koikuchi shoyus are the amount of wheat used in brewing and the amount of time the moromi (mash) is aged. For usukuchi shoyu, the brewer uses more wheat than they would for koikuchi. Wheat contributes a natural sweetness so adding more helps balance out the higher salt content. Usukuchi is also aged for a shorter time than koikuchi. To brew usukuchi shoyu, in the summer it only takes 2.5 months while in the winter it takes up to 8 months (the summer heat accelerates the fermentation process).
Suehiro has made a commitment to continue their traditional brewing methods. Maintaining that commitment is not easy - there used to be 60 shoyu breweries in Tatsuno City, but now there are only a handful (including the third largest soy sauce brewer in Japan). But sticking to their guns has allowed them to produce superior shoyu. They use soy and wheat grown in Japan. They brew in small batches. One thing that did surpise us it that they age in man-made tanks, not the cedar tanks used by other brewers we have visited. But the secret is that the building housing the tanks is made of wood, and that's where their specific strains of beneficial bacteria live, giving their soy sauce its unique taste. We think the resulting usukuchi shoyu is delicate and balanced in flavor. We are proud to be able to offer it to you.