Yuasa in Japan where the super popular soy sauce was born

Soy sauce is essential to accompany sushi

Carefully climbing the steep stairs, I followed Tsunenori Kano to the attic of his family’s soy sauce fermentation room, called Kadocho, which is 180 years old.

The dark space was eerily quiet except for the creak of my footsteps on the old wooden boards placed between the vats of soy sauce.

The sauce was dormant now, since it’s late winter, but it still filled the air with a savory aroma. Around me, a thick fungus-laden crust covered the ceiling, clung to the rafters, and grew up the walls.

“Those are the bacteria and yeasts that are as old as the building,” Kano, the seventh-generation fermenter, told me. “They provide the authentic flavor.”

I was in Yuasa, a quiet port tucked away in a bay on the western coast of the Kishu Peninsula in Wakayama Prefecture, on a quest to learn about the ancient origins of the holy grail of Japanese cuisine: soy sauce.

Soy sauce is possibly the most important condiment in Japanese cuisine. Its well-balanced sweet and salty flavor and deep layer of umami richness make almost any food taste more delicious and satisfying.

Its uses range from topping sushi to a splash in noodle soups and stir-fries, as well as the signature flavor of glazed dishes like teriyaki.

In 2017, the Japan Agency for Cultural Affairs designated Yuasa a Japan Heritage Site for being the birthplace of soy sauce, which is said to have been first made here in Japan in the late 13th century.

The now-beloved condiment came about shortly after a Japanese Buddhist monk named Shinchi Kakushin returned from a trip to China and became abbot at Kokoku-ji Temple near Yuasa.

He brought with him a recipe for making Kinzanji miso, an exceptionally thick type of miso made from whole soybeans, various other grains (such as barley and rice), and vegetables.

The townspeople of Yuasa soon discovered that the small amounts of liquid that collected in the fermentation vats of Kinzanji miso, as its ingredients were pressed with heavy stones, were delicious in themselves.

This byproduct, called tamari (a generic word meaning “to accumulate”) became the basis for soy sauce as we know it today.

soy sauce center
In a matter of years, Yuasa has grown from a way station on the Kumano Kodo pilgrimage route that leads to the famous temples and shrines of nearby Mount Koya to become the most important soy sauce manufacturing center in Japan.

In its heyday, the small town of just 1,000 houses was filled with more than 90 soy sauce fermentation sites, nearly one soy sauce shop for every 10 households.

Today, the city’s historic district is protected by Japanese law. It is a vast area encompassing 323 houses and other hongawara-buki (traditional buildings) recognized for their immense cultural value.

Many of them still retain their traditional barred windows and curved tile roofs, architectural features that were symbols to passersby of their owners’ prosperity.

There are five soy sauce shops and six Kinzanji miso makers that are still active. Visiting them tells the remarkable story of the intertwined fortunes of Kinzanji miso and soy sauce.

The distinctive flavor of Yuasa Soy Sauce reflects its ancient origins, from Kinzanji miso.

Unlike other types of miso, which are pastes used as condiments, Kinzanji miso is a nutritious dish with an elegant taste.

It is a culinary relic of Song dynasty cuisine, considered one of the world’s great culinary developments when exquisite new flavors were created from ordinary ingredients, and has remained a popular local delicacy throughout the centuries. which is enjoyed as a snack, side dish or even as a light meal when added to a bowl of rice or mixed with chagayu (a porridge made from rice, water and tea).

It was served to me at every meal while at Yuasa. Because their tamari byproduct was so tasty, the locals wanted a way to produce it in larger quantities.

They efficiently adapted the Kinzanji miso-making process to create soy sauce, a lighter but similar-tasting form of tamari.

Adaptation process
Established in 1841, Kadocho is one of the oldest soy sauce factories in Yuasa; the sauce they produce is as close to the original kind as you’re likely to find anywhere in Japan.

As we descended from the loft, Kano explained how the soy sauce making process was adapted from Kinzanji miso.

Pointing to ancient wooden tools and iron equipment, he said making soy sauce uses just two grains, rather than one variety – steamed soybeans and roasted wheat – which are mashed rather than left whole (as is the case of Kinzanji miso) to better extract its flavor and umami.

They are then mixed with koji kin (green Aspergillus oryzae mold spores), as is done with Kinzanji miso, and left for three days in a closed room, called a wall, where the temperature is carefully controlled.

There, the grains germinate and their starches are converted into sugars, allowing fermentation.

This mash is then placed in wooden barrels with plenty of fresh water and salt – instead of the watery vegetables used for Kinzanji miso – and the brew is fermented for at least 1.5 years to take on the same kind of flavor. smooth and complex that Kinzanji miso has.

Kano, a powerful-looking man, says that much of the work is done by hand. This includes regularly mixing the mash in their 34 large barrels with long wooden paddles and squeezing the soy sauce from the mash when ready.

Lastly, Kano slowly heats the soy sauce in an iron cauldron for half a day to stop its fermentation, using pine wood for the fire.