Love for making soy sauce

Okamoto Soy Sauce Brewery (Osakikamijima, Toyota, Hiroshima)

When I think of someone who has a great love for making soy sauce, I think of Yoshihiro Okamoto?san. Although the location of the brewery is in Hiroshima Prefecture, Osakikamijima is in fact an island, which is only accessible by ferry. In the past, island tours would stop by the soy sauce brewery as one of the attractions. But now, people make the journey from all over just for Okamoto’s soy sauce.

Yoshihiro Okamoto?san, his wife Okami Okamoto?san, and their two sons, Yasushi Okamoto?san (far left) and Tetsuya Okamoto?san (far right), all love soy sauce. If you ask Yoshihiro Okamoto?san about soy sauce, he won’t stop talking about it! This lovely family is incredibly genial, and I can feel their love and passion for soy sauce?making.

Brewing soy sauce in the center of the Seto Inland Sea

30 minutes by ferry from Takehara Port in Hiroshima Prefecture, Osakikamijima is an island active in shipbuilding and orange growing. On the island of 9,000 people, there is a lovely soy sauce brewery.

Carefully selected domestic soybeans, wheat, and sun?dried salt, they are all naturally?brewed in traditional kioke (a large wooden barrel). Okamoto?san watches over the 30 kioke barrels, full of delicious soy sauce, as they mature and ferment.

Osakikamijima is accessible only by ferry. In the spring, the fragrance of mandarin orange flowers drifts throughout the island, while in the fall, orange fruits fill the mountains.

Okamoto Soy Sauce Brewery is only a few minutes by foot from Hakusui Port.

The best hospitality

During the period of high crude oil prices in 2008, the cost of raw materials rose, causing many soy sauce breweries to increase their soy sauce prices. However, Okamoto?san did not raise his prices: “Although there was little to no business interest at the time, soy sauce is still an important element in Japanese cuisine. So that’s why I used all my effort and time to make good soy sauce,” said Okamoto?san.

Recently, there are many breweries using “tsuyu” or “broth” in their soy sauce, and they would keep the same recipe for the whole year. But Okamoto?san tries to accommodate his customers’ needs: “When it’s hot in the summer, I add a little bit more salt to the soy sauce. When it’s cold in the winter, I add a little bit of sugar to the soy sauce. I think that is the best hospitality?to be able to satisfy our customers.”

Because these ideas are the foundation of Okamoto?san’s soy sauce, he uses many keywords such as “nature” and “delicious soy sauce” when describing his products. Okamoto?san says, “Soybeans and wheat from the field, mixed with the salt from the sea. These raw materials turn into valuable koji (naturally?occurring mold grown on beans), and through the power of microorganisms, the soy sauce is fermented, experiencing Japan’s four seasons.”

Tetsuya Okamoto?san showing us how to steam the soybeans.

The steamed soybean and roasted wheat mixture is then taken to the koji room.

Then someone will spread the koji out evenly.

Making soy sauce for home cooking

When Okamoto?san had just inherited the brewery, he noticed that other shops would deliver the soy sauce to families across the island. He took up this trend and delivered his soy sauce too. After some time, as he was passing by some of the houses, there was a familiar fragrance in the air?it was his own soy sauce that people would use for cooking!

Okamoto?san realized that one house will cook vegetables this way, and another house will cook fish a different way. Each cooking style and taste is slightly different depending on the house. And since that time, he realized that “home cooking” is the base of soy sauce?making.

“When I was young, I wanted to make a variety of unique soy sauces, but then I thought about my family?it’s better to make delicious soy sauce that you can eat at home. Winter roots, spring vegetables, summer stalks, and autumn fruit, each are the best harvest of every season. I want to bring out these flavors in my soy sauce,” said Okamoto?san in a warm voice.

Traditional kioke barrels all neatly arranged.

The wooden paddle is used for stirring the moromi (main fermented mash).

When stirring, the moromi will look like this. As time goes by, the color will become darker and more uniform.

30 kioke barrels is the best one can manage

Naturally, mass?produced soy sauce cannot be brewed through traditional methods.

Depending on the natural surroundings where the brewery is located, and the nature of the microorganisms that live in the brewery, these factors will affect how the moromi is matured. Moromi is the key element that gives each soy sauce brewery its unique taste. If people touch the moromi or kioke barrels, then a type of white mold called “yeast membrane” will appear, negatively affecting the soy sauce.

Fortunately, stirring the moromi will prevent the white mold from appearing, but it is laborious work. With a 20 stone kioke barrel (about 3,600 liters or 792 gallons) that weighs more than three tons, stirring by hand is no small task. Every three days, Okamoto?san stirs all 30 kioke barrels by himself!

The raw material processing warehouse and the brewery are linked together by a small passageway. In front of the brewery is the Seto Inland Sea, while at the back of the brewery are mountains. This allows a nice natural breeze to pass through.

The ocean spread out before the brewery.

Wind passing through the brewery

Generally, if you use water to make soy sauce, then naturally?occurring mold called koji will appear. As it ages over time, the koji will easily accumulate moisture, which may cause an unpleasant odor.

But Okamoto?san’s brewery is different. His soy sauce’s fragrant aroma spreads near and far. Why is that? With thorough cleaning and organization of the brewery, along with the natural wind that passes through, this allows the aroma to spread.

With the mountains behind the brewery and the Seto Inland Sea in front, it becomes a natural air freshener. The trees up on the mountainside contain an abundance of oxygen, whereas the ocean wind has an abundance of natural minerals. The mountain and ocean breezes are constantly passing through, circulating to every corner in the brewery. The natural air carries the perfect amount of moisture, and always keeps the brewery in crisp condition.

Established in 2016, the new press and refining machine is kept in a cool, closed environment.

The uniform and precise pressing allows the soy sauce to stream through.

Using their hands, they will try to level the moromi as flat as possible.

Careful pressing

When you open the door and enter into the pressing and refining room, you will be surrounded by the smell of alcohol. This becomes proof that the yeast fungus is active and flourishing. What is also impressive is seeing the dozens of furoshiki, or “cloth wrapper,” all neatly stacked.

Unraveling the furoshiki, the moromi will be carefully wrapped in the furoshiki, and will look like a cushion. A person will stack dozens of the wrapped moromi sheets together. But in order to be flat and even throughout, a person would need to align the proper amount of the moromi in each sheet. This is a difficult task, so a person must have an eye of precision, and must be able to roughly calculate the appropriate supply of moromi in each sheet.

By slowly and carefully patting the moromi, it will even out. One of the employees that works with the moromi said, “I can’t tell if there are any subtle irregularities until I touch the moromi with my hand.” After hearing that, this type of work is extremely time?consuming. But after all, this is Okamoto?san’s soy sauce.

Brothers Yasushi?san and Tetsuya?san.

Okamoto-san’s love for soy sauce spreads everywhere


Handmade, naturally pure?brewed dark soy sauce, aged for 2 years100ml

Okamoto?san loves soy sauce so much that he won’t stop talking about it! Dark soy sauce made with domestic soybeans, wheat, and sun?dried salt, all brewed in kioke barrels. Carefully fermented and matured for two years in the warm weather of the Seto Inland Sea.

Price: \362 + tax
Ingredients: soybeans, wheat, salt


Okamoto?san’s love for soy sauce spreads everywhere


Handmade two?stage soy sauce, aged for 3 years100ml

Matured and re?fermented over a long period of time, the character and feelings of Okamoto?san are more apparent in this soy sauce, giving it a strong taste.

Price: \428 + tax
Ingredients: soybeans, wheat, salt, alcohol



Okamoto Soy Sauce Brewery

2577 Higashino, Osakikamijima?cho, Toyota?gun, Hiroshima Prefecture 〒725-0231
TEL:0846-65-2041  FAX:0846-65-2043