Vintage photo album with old photographs and documents on a wooden surface.

Matsuai

Uki, Kumamoto

Founded in 1827, Matsuai Shoyu is a seventh-generation soy sauce and miso brewery located in Kumamoto Prefecture on the Uto Peninsula in Kyushu, southwestern Japan.

Matsuai brews its soy sauce using “marudaizu,” whole soybeans. Instead of milling and defatting soybeans, a common practice in large commercial production, whole soy beans are fermented slowly, releasing and absorbing their natural oils and developing deep, complex umami.

Matsuai also only uses soy beans that are grown without the use of chemical fertilizers and pesticides. The company has been committed to sustainable agriculture since the 1970's. They have also fostered these agricultural practices locally in their area of Kumamoto.

In Japan, soy sauce made from domestically-grown whole soy beans accounts for 3 percent or less of total production. Soy sauce made from soy beans that are grown without chemicals during cultivation represents 0.3 percent or less of total production.

Matsuai also ages its shoyu for at least one year and presses it by hand, layer by layer.

Like most traditional soy sauce makers, Matsuai also produces miso. In addition, it makes rice vinegar and amanatsu citrus vinegar using fruit grown on its own farm.

From the moment I landed on Matsuai’s website, I was intrigued. The company is located in southern Kumamoto on the island of Kyushu, in southwestern Japan.

I had been to Kyushu a few times, but not as much as I wanted. My friends always lit up when they talked about the food of Kyushu. They often referred to it as “amakuchi.” While the word usually means “sweet,” in Kyushu it can also describe the richer flavors of shoyu, ramen, fried foods, and other dishes, which tend to be more robust than delicate or clean. Kyushu cuisine is sometimes described as one of Japan’s many regional “soul food” traditions.

Shoyu from Kyushu is typically “amakuchi,” (flavor) and “koikuchi,” (type) which is thick and dark. As I learned more about Matsuai, visiting, tasting, and getting to know them better, I saw Matsuai as an embodiment of Kumamoto, amakuchi, koikuchi, and umami.

I was also taken by their friendly, community-oriented spirit. Their company colors are taxi-cab yellow, black, and white and these bright colors and smiling faces characterized every picture and video. As I’ve gotten to know them, I’ve been welcomed with that same openness and enthusiasm.
- Henry

Matsuai Shoyu Brewery was founded in 1827 and will celebrate its 200th anniversary in March next year. The Matsuura family’s history dates back to the Edo Period (1603–1868), when several family businesses were called “Awaya,” such as Kami-Awaya and Nishi-Awaya. The head of Kami-Awaya eventually merged these businesses, forming what is now Matsuai.

The family has long followed the principle of “Ishoku Dogen,” reflecting their belief that food and medicine share the same source, and that choosing and eating the right foods is key to staying healthy.

For many decades, Matsuai has been committed to sustainable farming, natural production, and supporting the local community. Forty years ago, they became a founding member of the Kumamoto Organic Agriculture Research Association and helped establish the Matsuai Food Organic Council and Organic Producers Group to strengthen organic farming in their region. They also work closely with farmers to promote the use of non-GMO ingredients.

Matsuai also focuses on making the most of every resource through a circular approach. By-products from soy sauce and miso production such as soybean cooking liquid, soy sauce lees, and rice bran are recycled as compost on their own farm, where crops are grown without chemical fertilizers or pesticides. Soy sauce lees, rich in protein and salt, are also shared with vegetable and livestock farmers as feed or fertilizer. Soybean oil produced during brewing is even turned into soap used to clean factory equipment.

In 2026, they are expected to receive HACCP (Hazard Analysis and Critical Control Point) certification, an internationally recognized food safety system originally developed for the space program of NASA.