Yamakawa Brewery's Tamari Soy Sauce: A Gluten-Free Traditional Taste

• Table of Contents
• Yamakawa Brewery: Born in a Time of Turmoil
• Tamari Soy Sauce: The Deepest Flavor, Longest to Craft
• Wooden Barrels - Key to Soy Sauce Quality With Microorganisms
• Yamakawa Brewery's Tamari Soy Sauce Delivers the Taste of Tradition
• The Deep History of Fermentation Carried 100 Years into the Future

Yamakawa Brewery: Born in a Time of Turmoil

Take the bus for about 20 minutes from JR Gifu Station and get off at the Nagara Kitamachi stop, where you’ll be greeted by a fragrant aroma that tickles your nose. This aroma leads you to Yamakawa Brewery, a long-established tamari soy sauce brewery.

The company was founded in 1943 during World War II. It has continued to produce tamari soy sauce in Gifu while preserving traditional methods. We spoke with Kanako Yamakawa, the fourth generation owner.

Although few records remain from that time, Yamakawa explains the background to the company's founding as follows.

"The founder originally ran a liquor wholesale business, and apparently soy sauce was also on the shelves in the store at the time. I believe he began making soy sauce with the desire to make something that anyone could enjoy and would be useful to the local community."

Yamakawa Brewery has carried on the tradition of tamari soy sauce since the Kamakura period. The name comes from a liquid called “tamari,” which accumulates at the bottom of wooden barrels during the soybean miso-making process.

It’s said that soy sauce brewed in wooden barrels now accounts for less than 1% of the soy sauce distributed in Japan. Nevertheless, Yamakawa Brewery continues to carefully preserve the flavor of their soy sauce at its four breweries.

So, what exactly is soy sauce? How was tamari soy sauce created and developed?

The answer can be found in the "wisdom of fermentation" that the Japanese have inherited throughout their long history.

Tamari Soy Sauce: The Deepest Flavor, Longest to Craft

Soy sauce can be broadly classified into five types: dark, light, re-brewed, tamari, and white. Of these five types, the soy sauce brewed at Yamakawa Brewery is tamari soy sauce, which has the darkest color and deepest flavor.

This is because tamari soy sauce is aged for two years while regular soy sauce is aged for around six months. Over time, the proteins break down and the umami flavor becomes more concentrated.

The taste of the five types of soy sauce depends on the ratio of water, salt, soybeans, and wheat used as ingredients as well as the fermentation period. Yamakawa Brewery uses 100% soybeans, and brings out the original delicious flavor of tamari soy sauce without adding any gluten.

In contrast, white soy sauce is made from 90% wheat and 10% soybeans, resulting in a fragrant and light flavor.

"The more soybeans that are used, the longer the aging period. However, because of this process, the umami flavor is thoroughly extracted. If a lot of wheat is used, then fermentation will proceed more quickly and the rich aroma will emerge more easily," says Yamakawa.

Tamari soy sauce is known as a local soy sauce that has taken root in this region. Yamakawa Brewery continues to carefully produce "one drop of profundity" by being committed to traditional methods, dedicating both time and effort.

Koji Craftsmanship - A Fine Line Between Fermentation and Spoilage

The process of making tamari soy sauce begins with growing koji mold on steamed soybeans. Of the roughly 1,000 soy sauce manufacturers in Japan, there are not many that start by making koji, but Yamakawa Brewery has set up a dedicated room called the "koji room" where they make koji from scratch.

"Inside the koji room, the humidity is 100% with the room temperature at 30 degrees. It takes three days to make koji in this room. Koji mold, which has been propagated by humans since ancient times, is designated as Japan's national fungus. However, perhaps because it has been cultivated by humans, it will die off if left alone, so it must be properly looked after. There is something endearing about their slightly clumsy growth," Yamakawa said affectionately as she spoke about the charms of koji mold.

Fermentation and spoilage are chemical changes that lie on a very fine line.

We merely distinguish between what is beneficial to humans as fermentation and what is harmful as spoilage. Making koji for soy sauce is also a painstaking technique, honed over time, that requires careful monitoring of temperature and humidity to prevent spoilage.

Tamari Soy Sauce’s Unique Preparation Process Using Stone Weights

Once koji mold has grown on the soybeans, they enter the preparation process. The soybeans are placed in a wooden barrel, covered with a cloth, and then weighted down with stones.

Yamakawa told us, "The use of weights is a unique production method for tamari soy sauce. Because tamari soy sauce has a low water content during production, it cannot be stirred, or agitated, midway like other soy sauces. For this reason, we use weights to apply pressure and promote convection of the liquid.”

The brewing water is poured in after placing the weights on the soybeans. They use underground water from the Nagara River that flows below the soy sauce brewery. After purifying the water and adding salt, the mixture is poured into the wooden barrel, completing the preparations.

Regular soy sauce is fermented for around six months, while Yamakawa Brewery ferments its soy sauce for at least two years. The fact that it is made from 100% soybeans and prepared using traditional methods in a warehouse without heating or air conditioning allows the brewing of tamari soy sauce to be done more slowly and carefully.

The two-year brewing period is a time to trust in the power of koji mold and carefully observe its work. However, that doesn't mean that Yamakawa and her team just sit around and wait for two years.

After this, an important process that is essential to making tamari soy sauce begins.

Aging and Kumikake - Creating the Fermentation Environment

The process of "kumikake" is essential to support the activity of the koji mold. This process circulates the liquid to make the air and bacteria uniform to create the right environment for fermentation.

However, because the tamari soy sauce has been weighted, it cannot be agitated like regular soy sauce.

So when making tamari soy sauce in a wooden barrel, a tube is placed inside the barrel and engineered so that only water is collected. The water collected on top is scooped and poured back into the barrel - this is the "kumikake" process.

If this step is neglected, the oxygen-loving bacteria will gather on the surface and the oxygen-hating bacteria will sink to the bottom, causing the fermentation balance to be lost. Through the kumikake process, the brewers create an environment where each type of bacteria can thrive in harmony, and one step at a time, guide the tamari soy sauce to completion.

Aged Through Kibiki: The Essence of Tamari

After an aging period of about two years, the brewing of tamari soy sauce reaches its final stage. At this stage, regular soy sauce is extracted by applying pressure before being shipped, but tamari soy sauce has one more unique process that needs to be carried out.

This is the time-consuming and laborious process of extracting soy sauce, called "Kibiki."

Due to the preparation method of using weights that is unique to tamari soy sauce, the top of the wooden barrel becomes so hard over the course of two years that it cannot be drawn up with a pump. Therefore, tamari soy sauce is extracted using a method called "Kibiki," which draws only the liquid from a tap at the bottom of the barrel.

Although the soy sauce comes out vigorously at first, it takes about a year for the solids inside to completely dry out. Not only does aging take years, but even the Kibiki process requires time unique to brewing tamari soy sauce, which also contributes to its depth and umami.

After the Kibiki process, what remains in the wooden barrel are the soybeans that were used to make the tamari soy sauce.

The completely solidified residue is scooped out by the brewers by hand using shovels.

This solid material is then thinly sliced and put through a compressor to be brought back to life once more as soy sauce.

The amount of soy sauce obtained by compression is almost the same as that obtained by the Kibiki process. It is compressed twice to thoroughly bring out the full potential of the ingredients.

At Yamakawa Brewery, these two soy sauces are given different names. The soy sauce bottled with the Kibiki method is called Nagara, while the one extracted by pressing is named Minobi.

After stating this, Yamakawa spoke quietly, "Without this method, we would not be able to make our traditional rich, thick tamari soy sauce. In order to preserve this flavor, we spare no time and effort in our soy sauce production."

From their sincere gazes, we could see the pride of the brewers that has been passed down since the company's founding, and their strong determination to ensure that the tradition of tamari soy sauce continues.

Wooden Barrels - Key to Soy Sauce Quality With Microorganisms

Microorganisms are vital to soy sauce production. While that is often thought to be the case, it is said that another key factor that determines the quality of the soy sauce are the wooden barrels.

The wooden barrels used at Yamakawa Brewery have been in use since the brewery was founded during the times of war. What's more, the barrels that were collected at the time of the brewery's founding were actually hand-me-downs from previous sake breweries.

"At this rate, one day, all the wooden barrels may break simultaneously."

Yamaroku Soy Sauce, a brewery on Shodoshima Island, was the first to notice this crisis. Yamakawa Brewery endorsed the "Kioke Craftsmen Revival Project" launched by Yamaroku Soy Sauce, and ordered new barrels in 2018. They began activities to pass on the culture of wooden barrel brewing to the next generation.

However, when they tried brewing soy sauce in the new barrels, it tasted different from the flavors produced by their previous barrels. Similarly, it was lighter in color than Nagara made with the Kibiki process, and had a crisp soy sauce aroma.

The ingredients, environment, and preparation methods were all the same. The only difference was the barrels.

Looking back, she mentioned that about 25 years ago, they tried brewing tamari soy sauce in plastic tanks instead of wooden barrels. The resulting tamari soy sauce had a noticeably different aroma and richness, despite the test results being exactly the same.

Based on this experience, Yamakawa states, "The wooden barrels contain an ecosystem that can only be found here."

"When you use a plastic tank, fermentation only progresses in the ingredients placed inside. But wooden barrels contain living microorganisms that have developed over years of brewing. I believe it's the lactic acid bacteria and yeasts that act on the ingredients, bringing the tamari soy sauce to completion."

Currently, the new barrels have completed their first brewing and are undergoing their second brewing. Microorganisms from the wooden barrels steeped in history will travel through the air of the brewery, settling into the new barrels and gradually cultivating their own unique ecosystem, eventually becoming "Yamakawa Brewery’s wooden barrels."

Yamakawa Brewery's Tamari Soy Sauce Delivers the Taste of Tradition

Tamari soy sauce is carefully prepared using traditional methods.

Yamakawa Brewery's signature products are two types of tamari soy sauce–Nagara and Minobi–each distinguished by its extraction method.

Nagara: Made with 100% Domestic Soybeans

Nagara is made using only whole soybeans from Gifu Prefecture and underground water from the Nagara River. Regular soy sauce contains wheat as an ingredient, while Nagara is a gluten-free tamari soy sauce with no wheat whatsoever.

Compared to regular dark soy sauce, it has a deeper and more delicious flavor with even the smallest amount providing a commanding presence.

The strong flavor is perfect for savoring over cold tofu or grilled fish.

Minobi: Every Drop of Flavor Drawn Out by Compression

Minobi is made by compressing the soybeans left behind after the production of Nagara.

It takes a year for the brewers to dig the soybeans up by hand and fermentation continues until it is slowly pressed, resulting in a mild saltiness that differs from Nagara.

It is suitable for dishes that require strong seasoning, such as simmered fish and teriyaki meats.

A Variety of Flavors Using Soy Sauce at the Direct Sales Shop

You can pick up and buy these products at Yamakawa Brewery's direct sales shop. The walls of the shop are lined with soy sauces, including Nagara and Minobi, and you'll be captivated by their rich colors and appearance.

Another great thing about this shop is that they have a wide selection of items that are perfect as gifts, such as rice crackers, soy sauce madeleines, and sable cookies made with Yamakawa Brewery’s soy sauce.

Additionally, when you purchase tamari soy sauce, you will receive a paper with a special recipe passed down from the fourth generation owner’s grandmother. If you visit the shop after learning about the charms and history of soy sauce on a brewery tour, you will be able to enjoy shopping even more.

The Deep History of Fermentation Carried 100 Years into the Future

Even in today's world where it is difficult to think of soy sauce as a fermented food product, Yamakawa Brewery is committed to their brewing process, from making koji to the preparation, and continues to pass down the tradition of tamari soy sauce-making using wooden barrels to the next generation.

They also occasionally hold events such as brewing with new barrels, brewery tours, "open house" days, and even tamari soy sauce-making workshops using fruit jars. They continue to share the depths of fermentation that cannot be fully explained by science or theory alone.

If you visit Yamakawa Brewery and discover each step of how tamari soy sauce is made, you will realize how much the workings of fermentation, which we do not normally notice, contributes to the rich flavors we bring to our dinner tables.

Tamari soy sauce brewed in wooden barrels; Yamakawa Brewery has continued to produce soy sauce amounting to less than 1% of the soy sauces distributed in Japan. They not only continue to brew their products, but also stay committed to their manufacturing methods, dedicate themselves to preserving their wooden barrels, and pass on their techniques to the next generation.

Quietly observing their conviction in brewing tamari soy sauce with time, care, and deliberately inefficient methods is a wonderful way to show your support from your own dinner table.

Yamakawa Brewery

1-9 Nagara Aoicho, Gifu City, Gifu Prefecture