Visited Isegura
The fermentation hall of Isegura, in operation for over 100 years, blends centuries-old wisdom with creative innovations suited to modern times.
At the entrance, visitors are greeted by floor sheets for disinfecting shoes. Though designed to remove dirt, the sticky sound they make underfoot adds a playful touch to the visit. Inside, small wooden barrels filled with miso and large stirring ladles are on display. Visitors can even try stirring the miso themselves, observing the koji mold, smelling the aroma of fermentation, and feeling the weight of the ingredients—engaging all five senses in the process.
This hands-on experience is especially aimed at children, giving them the chance to learn the joys of fermentation. The fifth-generation owner, Kazuhiko Shikii, emphasizes that the experience is not just about watching, but about participating, and this philosophy is evident throughout the fermentation hall.
In the production area, custom-built machines cool steamed soybeans and coat them with koji. The koji room and pasteurization equipment, also crafted by previous generations, allow precise control and easy adjustments over time. During my visit, the koji room was being renovated, with stainless steel sheets installed to maintain optimal temperature.
Barrels are wrapped in styrofoam to moderate temperature differences with the outside air, and plastic sheets or panels prevent splashing during stirring. The team at Isegura continually asks, “How can we make this even better?”—implementing improvements directly on the production floor.
This dedication to constant refinement is the hallmark of Isegura.
Mr.Shikii explains, “The innovations in machinery and white soy sauce began with the third generation, and the fourth generation expanded our product range with items like dressings. My role is to introduce Isegura to as many people as possible.” After studying industrial engineering at university, he gained experience in a bakery and a machine tools company before returning to the family business. Under the guidance of his father, he mastered delicate fermentation techniques and aging judgments that only seasoned craftsmen can make. Since taking over, he has honored tradition while embracing new challenges.
Isegura participates annually in a project to revive wooden barrel craftsmanship. They have developed increasingly popular gluten-free tamari soy sauce, as well as a new variety that strikes a balance between traditional tamari and dark soy sauce to suit the lighter tastes of local young people. The company has also ventured into international exports and refreshed product packaging to be more accessible and appealing. In recent years, they revived the traditional production of white soy sauce in wooden barrels, after decades of using enamel tanks.
Although enamel tanks had preserved flavor and color since the late Showa period, Isegura believed that the true taste could only be achieved in wooden barrels. They acquired barrels over 50 years old from a Gifu Prefecture soy sauce brewery, overcoming water leakage issues with nationwide support. By the winter of 2024, they successfully produced white soy sauce in wooden barrels once again.
The fifth-generation owner Mr.Shikii has inherited a relentless spirit of innovation from his predecessors. Each initiative reflects Isegura’s philosophy of “preserving tradition while embracing innovation.”
This year, particularly hot weather has forced the company to delay the preparation of raw materials—a challenge unprecedented in their history. Mountains of wheat and soybeans patiently await their turn, a reminder of the delicate balance required in fermentation.
During my visit, Mr.Shikii recommended the “Whole Soybean Tamari Soy Sauce.”
“Tamari is often thought to be gluten-free, but traditionally it contains wheat. The aroma is completely different,” he said proudly. His wife suggested dishes using “Wooden barrel White Soy Sauce”, such as lightly pickled cucumbers and tomato clear soup—simple meals that bring flavor to the table.
Locals and visitors from afar alike insist that only this store’s soy sauce and miso will do—nothing else satisfies, and even the children refuse to eat anything else. By cherishing close community connections, Isegura has fostered deep trust across generations.
Inspired by his wife’s vivid descriptions that made the dishes come alive, I left the store with a recommended bottle of soy sauce in hand.
September 12, 2025