Workplace experience at a white soy sauce brewery!

Junna.K
Oct 12
6 min read

Hello, I'm Junna, a sushi instructor! It's October now, and it's getting cooler in Kyoto.

To learn more about soy sauce, an essential ingredient for sushi, I recently went to Nitto Jozo(Brewery) in Hekinan City, Aichi Pref, to learn how to make white soy sauce. In this blog, I've written about what I learned and felt about the traditional Japanese soy sauce making process that has continued for ages. I think it's very interesting, so I hope you'll read it all the way through.

Nitto Jozo(Brewery)

Founded in 1938, the company is headquartered in Hekinan City, Aichi Pref, and brews white soy sauce. Located about a two-hour drive from the headquarters, deep in the mountains of Asuke, Toyota City, the company also brews "Shirotamari," Wheat-brewed seasoning, using a unique manufacturing method at its Asuke Brewery.

https://nitto-j.com/

White soy sauce and Shirotamari

Soy sauce is an essential ingredient in Japanese home cooking. The most commonly used type is "Koikuchi soy sauce." This is made with soybeans and wheat in a 1:1 ratio, and has the best balance of flavor and aroma.This is the most basic soy sauce.

Nitto Jozo, which I visited this time, produces "white soy sauce" rather than Koikuchi soy sauce. Hekinan City, where the brewery is located, is the birthplace of white soy sauce, and it has been eaten in this area for a long time. In the past, white soy sauce was often used in restaurants, and was used for dishes that did not need to be colored. It’s a soy sauce that brings out the natural goodness of the ingredients — in both flavor and appearance.

White soy sauce is made with soybeans and wheat in a 1:9 ratio. Because it contains less soybeans, it has a weak umami flavor, but it is characterized by the strong fragrant aroma and sweetness of the wheat. Another feature is that because it contains a lot of wheat, it does not easily become discolored even after aging.

In addition to white soy sauce, they also produce a soy sauce called "Shirotamari." This soy sauce is a very precious soy sauce that is only produced by Nitto Jozo in Japan.

The method of production is almost the same as that of white soy sauce, but its biggest feature is that it does not contain soybeans. Because it does not contain soybeans, it has an amber color that is closer to transparency than white soy sauce.

Asuke Brewing - Producing Shirotamari

White soy sauce and Shirotamari are prepared and fermented in a different location.

They have been making white soy sauce for a long time, and wanted to change the weak point of white soy sauce, which is its saltiness, so they created Shirotamari.

At the beginning of development, they thought, "If we increase the amount of wheat, it will taste sweeter and less salty," so they gradually reduced the amount of soybeans while making soy sauce, eventually arriving at a 10:0 wheat to soybean ratio. However, this didn’t mean that it was complete, and the next problem arose. By reducing the amount of soybeans to 0 and increasing the proportion of wheat, the sweetness came out, but the umami flavor was greatly reduced and it ended up a bland taste. Next, they tried making it with twice the amount of malt, and although the taste was much better, the color became darker and the distinctive characteristics of white soy sauce were lost.

From there, they reconsidered the way to make malt, found their own unique manufacturing method, and the current Shirotamari was born.

Ten years after Shirotamari was born, Yoichi Ninagawa, the current president, took over and began making Shirotamari. At first, he made Shirotamari at the headquarters in Hekinan, but he began to feel uneasy about using tap water and began searching for tasty water. One day, he came across a spring in Otaga, a village in the mountains of Asuke. When he tasted it, he loved the soft, delicious water, which was soft and slightly sweet. He intended to take it back to Hekinan (a brewery that makes white soy sauce) and make it himself, but when he looked around, he found a closed elementary school next to the well water, and was captivated by the old houses and beautiful natural environment in the surrounding area. Instead of bringing it back to Hekinan, he renovated the closed elementary school, placed wooden barrels there, and began making Shirotamari.

Workplace Experience - Asuke Edition

So far, I have written about the history of Nitto Jozo and the story of how Shirotamari was born. From here on, I will write about my experience making soy sauce at the brewery. First, I will talk about the work done at the Asuke brewery where Shirotamari is made.

It takes about two hours by car from the headquarters. Just getting to the workplace was physically demanding, as I had to climb mountain roads to get there.

・The first task I did in Asuke was installing the spigot on the wooden barrel.

This spigot is where the finished Shirotamari comes out. If this spigot is not attached properly, it will leak during aging, so this is a very important process.

First, Japanese paper(Washi paper) is wrapped around the spigot to avoid the wood from deteriorating due to contact with other wood. After that, the spigot is inserted into the wooden barrel and struck with a wooden mallet. Finally, the spigot is fastened tightly with thread to prevent it from coming off, and preparation for brewing is complete!

Preparation

・Make salt water

Water from Asuke is pumped into the tank, and then a specific amount of salt named “Umi no Sei” is added, mixed in a mixer for about 25 minutes, and the mixture is complete.

・Put salt water in a wooden barrel

The salt water is sent into a wooden barrel using a hose.

The malt is brought from the Hekinan headquarters and placed in a wooden barrel, completing the brewing process! After one to four days, the surface of the mash is covered with cloth and wooden boards, and then weighted down with a blue bag filled with water.

This process is done to prevent the surface of the mash from drying out. By placing weights on top, the surface is filled with salt water, to avoid it from drying out.

・Aging and fermentation: Approximately 3 months

There are many wooden barrels in the brewery that have finished preparation of raw materials.

・Raw pull

The Shirotamari is removed from the wooden barrels and transported from the Asuke brewery to the Hekinan brewery where it is filtered.

・Cleaning up after work is essential!

They always kept the brewery clean by carefully putting away the tools they needed for work after using them!

Workplace Experience - Hekinan Edition

On the last day, I worked at the Hekinan headquarters, where white soy sauce is made.

Here, malti making, filtering of shirotamari brought from Asuke, bottling, and preparation of white soy sauce are all carried out.

・The first thing I experienced was removing the lees of white soy sauce from the bag after squeezing.

Carefully remove the soy sauce lees from each piece of cloth, ensuring no residue remains on the fabric, as this will make it difficult for the next person to wash the cloth.

Rather than thinking about finishing their own work quickly, they seemed to be working very carefully, passing the baton to the next person in a way that made it easy for them to do their work.

・Next, I observed the malt making process.

The malti-making machine is made using a very unusual machine called a "trommel type."

Using this machine apparently reduces the risk of bacterial infection. It produces malt with high amylase activity, meaning it has a strong ability to change starch into sugar, resulting in white soy sauce with a high sugar content.

Once the malt is ready, it is transferred to the preparation tank using a hose.

White soy sauce is brewed in 10,000 liter tanks made of FRP (fiber reinforced plastic). These tanks are resistant to water and salt. One tank can make 8,000 liters of white soy sauce!

・I observed the filtration process.

The filtration of Shirotamari and White Soy Sauce is carried out at the Hekinan headquarters.

They filter it at least twice: they add diatomaceous earth, whose tiny holes remove sediment and microorganisms.

This process is also carried out every 5 minutes, with the pressure of the filter and the amount of diatomaceous earth added being adjusted.in detailIt was recorded.

・The last thing we experienced was the process of putting the mash into a cloth before pressing it into white soy sauce.

It may seem like a simple process of just wrapping it in cloth, but when I actually tried it, I was surprised at how difficult it was!

9-12L of mash is placed in one bag, and 110-120 bags are stacked together and pressed. White soy sauce is filtered after pressing.

lastly

I felt that the people who make these amazing seasonings put in a tremendous amount of effort. I only had the opportunity to experience it for three days, but the people who make them repeat the same tasks every day. I think it's really amazing that they can work so carefully and efficiently under such circumstances.

As a consumer, I can't help but feel grateful that the reason we can continue to enjoy delicious soy sauce is because of the people who work hard every day to make it.

I would like to continue sharing Nitto Brewery's Shirotamari, which has a long history and tradition since ancient times for many people.