What is wooden barrel brewed soy sauce?

Soy sauce fermented and aged in wooden barrels. Until the Edo period, basic seasonings such as soy sauce, miso, vinegar, mirin, and sake, which are the base of Japanese cuisine, were made in wooden barrels, but due to cost-effectiveness, the use of wooden barrels has steadily decreased, and in the soy sauce industry, it has fallen to less than 1% of the total.

However, since 2000, when brewing using wooden barrels nearly went extinct, there has been a movement to reconsider the practice, particularly among young brewers, and breweries seeking greater flavor and individuality have begun to use them more actively.

The appeal of wooden barrel soy sauce is its diverse characteristics, just like craft beer

The wooden barrels used to make soy sauce are about 2-3m high and 2-4m in diameter, and can be used for over 100 years. Microorganisms live in the fine structures on the surface of the wood, creating a unique ecosystem.

This is the greatest feature of the wooden barrels; the unique characteristics of the original microorganisms, which have been accumulated over more than a hundred years of history and have developed over the climate and soil, give rise to flavors and tastes that can only be produced by that brewery.

Taste made by nature

The wooden barrels are containers made from natural materials without the use of iron nails or adhesives. The fermentation environment is not temperature-controlled artificially, but rather is "natural fermentation" achieved by seasonal temperature changes.

Preparation is done in the cold season, and fermentation begins in the summer. Depending on the season, the wooden barrels absorb moisture and keep warm when it's cold. As they change appearance, they create the perfect environment for soy sauce.

Taste created by time

The lifespan of a wooden barrel is said to be 100 to 150 years, and it has been used for generations. Many of the barrels still in use were made in the Meiji to early Showa periods, and the soy sauce breweries that own these barrels have even longer histories.

Wooden barrels are often made from cedar, which takes decades to grow. Furthermore, to grow high-quality timber like Yoshino cedar in Nara Prefecture, it is necessary to start from cultivating the forests, which shows the efforts of our predecessors over hundreds of years.

Taste created by people

The flavors change every day. The end product also changes depending on the year. The brewers have a variety of approaches to the process, such as "It's always different, so I'm always worried...", "I trust the wooden barrels and leave it to them!" and "It's a lot of work, but it's also fun."

The more delicate the brewers are, the more frequent they are, while the more daring ones are boldly trying new methods. It is said that the taste of the soy sauce resembles the personality of the brewers. However, what they have in common is that they make soy sauce that they themselves find delicious. Wooden barrels are being reconsidered to better bring out the individuality of the brewers.