PRODUCER SPOTLIGHT: Exclusive Interview with Marunaka Shoyu - Protecting a 200-Year-Old Tradition and a 3-Year Brewing Process - Not Your Typical Soy Sauce

  • 9 min read

Marunaka Shoyu's soy sauce

We had the honor of sitting down with Atsuko Okabe, Executive Director of Marunaka Shoyu, to hear her story of perseverance and determination in sharing her family's 200-year-old traditional soy sauce with the world. Please enjoy this inspirational exclusive interview.

Not your typical soy sauce

Have you ever tasted soy sauce from 200 years ago? Can you describe the taste and smell of soy sauce that has been aged for three years?

Very few people can answer "yes" to these questions with confidence. Once you've experienced a soy sauce made using the same old-fashioned methods from 200 years ago -- as well as the original equipment and fermenting microorganisms, you will quickly understand what real soy sauce should taste like. 

Marunaka Shoyu's soy sauce

I'll burn this storehouse down!

Due to the rise of cheap ingredient imports and the introduction of mass production by machines, the time-consuming traditional method of brewing soy sauce was once on the verge of disappearing.

Mr. Masakazu Nakai, the 8th president of Marunaka Shoyu,was working in his family's brewery when he first noticed the merits of authentic soy sauce processing.When he decided to take over his family's business, his sister, Atsuko Okabe, had a very important decision to make. 

Atsuko Okabe, current Executive Director of Marunaka Shoyu and Masakazu Nakai's older sister, is in charge of product design as well as domestic and overseas salesShe grew up in Shiga Prefecture on her family's brewery. From spring to summer, during the fermentation process, no one except skilled workers were allowed to enter the brewery's storehouse since maintaining the temperature and humidity required for the microorganisms to remain activated is very difficult and sensitive. Once, when Atusko's grandfather found out that she had gone to school by passing through the storehouse, he scolded her. In response, she screamed back: “I'll burn this storehouse down!”

Marunaka Shoyu's Soy Sauce

Needless to say, she never did burn down the storehouse. Instead, in support of her brother's desire to protect the inherited microorganisms and traditional manufacturing methods of her family's soy sauce business, she battled to save the company from going out of business. Today, she shares the value of Marunaka Shoyu's traditions with people in Japan and around the world. 

”What is different about your family's soy sauce?” 

WhenMs. Okabe first started selling her family's soy sauce to retailers, she was frequently asked: "What is different about Marunaka Shoyu's soy sauce?" There arearound1,300 soy sauce breweries throughout Japan, and with various products such as dashi soy sauce andother flavoredsoy sauce on the market, it was difficult to convince retailers to sell Marunaka Shoyu's soy sauce. For the first time, Ms. Okabe felt nervous that she didn't know enough about her family's business.

“It's a soy sauce that incorporates andeven improves all the ingredients it mixed with without overpowering them. Just one drop of our soy sauce enhances the flavors while cooking."Ms. Okabe said

Ms. Okabe

Soy sauce used to be a luxury seasoning

Japanese fermented foods include miso, soy sauce, and sake, with soy sauce being the most widely known. It was introduced to Japan in the 7th century from China and has been exported to Europe since the Edo period.

Marunaka Shoyu's Soy Sauce

Even though they are both fermented foods, miso (fermented soybeans) andsoy sauce arecompletely different. Once miso is brewed, it doesn't require anyadditional hand processing to help itmature. Misoremains in a solid form, while soy sauce is turned from a solid (soy) into a liquid. It takes additional time and effort to create this liquid through fermentation using natural microorganisms (koji)and natural climate changes. Because of this, soy sauce was originally a luxury item.

Now, however, the price of soy sauce is as low as or even less than a bottle of water. Why is that? It's because modern soy sauce is often produced from fat-free soybeansimported from the United States that are intended to be used as livestock feed. Soy is imported cheaply and produced using a short ripening period of three weeks to six months using mechanical means.

"Price" has various messages

Customers only see the final price without knowing if the soy sauce is machine-manufactured or traditionally made.

How are products that originally took more time and effort to make than miso being sold at a cheaper price? The answer is in the raw materials, the aging period, the time, the work, and the message hidden behind the price.

Brewer's bacteria made by a lake and mountain range

Marunaka Shoyu's Soy Sauce



Marunaka Shoyu is located in Shiga Prefecture on the shores of Lake Biwa, Japan's largest lake. In winter, the combination of the humidity from the lake, the northern wind, and the Suzuka Mountains to the south creates a heavy snowfall thatmakes for a difficult but uniquebrewing climate. This stands in contrast with the many soy sauce storehouses located on the warm Pacific side of Japan, in places such as Wakayama, Chiba, and Kagawa, where fermentation happens faster and easier.

The natural climate surrounding Marunaka Shoyu helps to shape the unique blend of its koji.

Marunaka Shoyu's Soy Sauce

“The taste from the brewer's bacteria seems to be attributed to the climate of each place." Mr. Nakai explains. Marunaka Shoyu's koji is still alive in the same barrels in the original storehouse more than 200 years later. Because of this rich history, the storehouse is registered as a National Tangible Cultural Property.

Marunaka Shoyu makes every effort to protect its koji. The brewers who perform the work spend time observing the craftsmen before embarking on a 5-10 year apprenticeship.

"There are things you can't make without time and effort," says Mr. Nakai

Marunaka Shoyu's Soy Sauce

How is Marunaka Shoyu's soy sauce made?

First, soybeans and wheat, which are the raw ingredients, are purchased directly from farms that use pesticide-free cultivation and have complete traceability.

Then, the steamed soybeans are naturally fermented by the koji in the barrels, increasing their sweetness and umami. Simultaneously, roasted wheat adds a fragrant scent.

Marunaka Shoyu's Soy Sauce

Salt is indispensable for brewing soy sauce, but also has an antibacterial effect that if used incorrectly can kill the good bacteria. Marunaka Shoyu uses a process called “Salt Suspension" or "Shiotsuri", that no other company in Japan uses.

During this process, hemp bags filled with salt are placed in wooden vats containing water, allowing the salt to dissolve slowly over time. Shiotsuri gradually increases the salt content of the water, activating the koji living in the barrels and readying them for the next phase.

The next phase is "kaiire", which takes nearly three years to complete. During this period, brewers rely heavily on their skill and knowledge of the brewing craft, constantly interacting with the ingredients to control the temperature and fermentation process. 

Marunaka Shoyu's Soy Sauce

The brewers carefully blend the moromi (the mixture of soybeans, wheat, and salt) with the koji in the wooden barrels and stir it with a wooden paddle to draw out its complex flavors and aromas.

Marunaka Shoyu's Soy Sauce

Twice a day, each barrel is attended to by a brewer who carefully stirs and enlivens the mixture by releasing built-up gases and reintroducing oxygen into the moromi. Throughout this stage, the brewers create the ideal fermentation environment, allowing the koji to thrive and flourish.

As with all processes at Marunaka Shoyu, this step is entirely reliant on the technique and experience of the brewer, and no automation or modern equipment is used.

Marunaka Shoyu's Soy Sauce

“Funashibori”, or “Boat Squeezing”, is the final step in the process and arguably the most physically demanding. The moromi is removed from the barrels and transferred to hemp sacks, where gravity filters the soy sauce naturally through the sacks over the course of a week. Finally, the bags are squeezed by hand. The remaining liquid is pasteurized to stop the fermentation process and packed into bottles.

Marunaka Shoyu's Soy Sauce

Marunaka Shoyu's Soy Sauce

The soy sauce made from each of Marunaka Shoyu's individual barrels will have a slightly different taste based on the unique koji and differences in fermentation. Thus, their soy saucesare blended to create a uniform product.

The result: an exceptional soy sauce unlike any other.

Marunaka Shoyu's soy sauce

“There are some things you can't make without time and effort,” says Mr.Nakai, Marunaka Shoyu's president.

The fermentation period for mass-produced soy sauce is up to six months, and even so-called high-grade soy sauces take only one and a half to two years to make. Marunaka Shoyu's soy sauce takes three years.

“To continue using traditional manual labor and time while protecting the brewing koji in the face of fast food is very difficult,” explains Mr. Nakai.

The chef at Kikunoi, a restaurant famous for its Japanese cuisine, says: “The most important thing in cooking is the seasoning, and Marunaka Shoyu's soy sauce, which has a fragrance even when heated, is special.”

Ms. Okabe said in Europe, “Because of its delicate fragrances and gustative qualities, you can taste our soy sauce as you would a fine wine: by putting a single drop in a red wine glass. Swirl the glass. Inhale deeply. Cover the glass with your hand, swirl it again, remove your hand, and smell it again. Then with the tip of your finger, put a droplet of soy sauce on your tongue and let its taste and fragrance expand in your mouth."

Tasting: (

Marunaka Shoyu's Soy Sauce

Marunaka Shoyu's soy sauce is now used in many Michelin-starred restaurants throughout Europe and Japan.

It was also used at the G20 dinner table in Osaka, where all the finest and representative foods from around Japan were served. Marunaka Shoyu's soy sauce was proudly presented for its tradition and history.

A message from Mr. Nakai, Marunaka Shoyu's president

"Marunaka Shoyu's soy sauce is a soy sauce that has been aged in a brewery for over 200 years. "Don't think this is just a soy sauce.” With just a single drop, the taste of the ingredients in dishes will change.

At first, you may think that Marunaka Shoyu's soy sauce is expensive, but only a small amount is required. People who are health-conscious and care about their salt intake tend to avoid soy sauce, but that's because it's frequently overused. You can enjoy the rich taste and aroma with just a small amount.

Even if you compare it with other fermented products such as wine, you can appreciate its tremendous value considering a bottle of wine can be consumed over just one meal, while Marunaka Shoyu's soy sauce can be enjoyed for over a month even if you use it every day. 

In the future, we will continue to protect our brewery and our old-fashioned manufacturing methods in order to produce the best soy sauce. I hope you will enjoy the flavor and aroma of Marunaka Shoyu's soy sauce."

Marunaka Shoyu's Soy Sauce

Mr. Nakai, the brother and president, and Ms. Okabe, the sister, executive director, and teller of Marunaka Shoyu's story, differ in their approaches, but their core beliefs are the same. Ms. Okabe has a pure enthusiasm that moves people's hearts, while Mr. Nakai has a devotion to the creation of their soy sauce that further strengthens the spirit of protecting their tradition.

"Looking at the people who continue to make and brew our soy sauce, the people who appreciate the product, and the people who continue to love it, I feel that the rapid growth of our soy sauce with a history of 200 years has just begun."

Customer reviews

“I have been looking for an authentic soy sauce. I feel your company truly creates a real one that embraces Japanese tradition. My daughter has three kids and I would like my grandchildren to experience the real taste of soy sauce from a young age. To protect a company like yours, we need to educate the younger generation. Please keep creating your products while continuing to not be too commercial.”

“I can’t eat sashimi (raw fish) without your soy sauce anymore, especially tuna. A simple and easy soup for ramen can have a huge difference with just a little bit of your soy sauce. Cooked rice with tofu becomes a luxurious meal by adding your soy sauce. I always add it to curry or fried rice for extra flavor. It costs several times more than normal soy sauce but it makes our lives happier. That happiness is more than I expected which is why I'm reordering them again like this. (lol) ”

"It’s good. It made me re-think what I was using previously, and I've started to reconsider the role of soy sauce in daily cooking. I recently started carrying it when I travel as well.”

“Your soy sauce is extraordinary. I have experienced the greatness of soy sauce for the first time in my life. Each of my family members is impressed every time we use it. Regular soy sauce tastes like ‘adding soy sauce’. But Marunaka Shoyu's soy sauce awakens the potential of the ingredients and makes it rich in flavor. This brings harmony to the dish itself, and the taste and aroma spread inside your mouth. This feeling is very hard to describe. Its exact meaning is 'Excellence'." 

Editor's note: 

Even before opening the package and the bottle, you will experience the beautiful aroma. Every time you open the bottle, the taste and fragrance will fill your mouth with flavor and bring pleasure to every meal. 

A good aged wine is 20-50 times more expensive than the average, but Marunaka Shoyu's soy sauce is only 3-4 times more expensive. Considering how long it lasts and how much each meal changes with just this one drop of this seasoning, it's not a very expensive purchase. Savor Marunaka Shoyu's soy sauce as you would a fine wine.

I hope that such a culture extends not only in Japan but around the world.

Learn more about Marunaka Shoyu at:



Interviewer, Original author: Aki Sugiyama
English author: Lillian Rowlatt

Co-founder of Kokoro Care Packages. Based and raised in Tokyo, Japan, Aki Sugiyama is half Okinawan and studied abroad in Australia. She spent 8 years in a career in finance before co-founding Kokoro Care Packages with Lillian Rowlatt in 2018. She's a bookworm, coffee addict and fitness competitor having represented Japan nationally.


Co-founder of Kokoro Care Packages. Lillian is a half-Japanese, half-British Canadian currently living in LA. She spent almost a decade in finance (capital markets) before co-founding Kokoro Care Packages with Aki Sugiyama in 2018. She is passionate about sharing her Japanese heritage and preserving the traditions of Japan. She has a math degree and studied Kumon for 14 years while being ranked #1 in North America. She believes in the power of community and connections, nature and wellness, and the importance of a good night's sleep.

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