
Founded in 1893, Iio Jozo is nestled just outside the picturesque seaside town of Miyazu and is renowned for producing what many consider to be Japan’s finest rice vinegar. This reputation has been earned through a steadfast commitment to using the best ingredients and adhering to time-honored traditional methods. Uniquely, Iio Jozo oversees the entire production process, even growing a portion of their own rice to ensure exceptional quality.
Fifty years ago, the third-generation Iio-san observed that pesticides used by local rice farmers were devastating the natural ecosystem of the paddies. Understanding the impact this could have on both health and the environment, he persuaded local farmers to switch to pesticide-free practices. To this day, Iio Jozo continues this legacy, using only 100% new-harvest, pesticide-free rice to craft their vinegar, delivering purity and excellence in every bottle.
Today, Iio Jozo is led by Akihiro Iio, the fifth-generation president who continues his family’s unwavering dedication to traditional vinegar-making while thoughtfully looking toward the future. Under the guidance of his father, Iio-san has mastered the art of crafting exceptional rice vinegar by controlling and perfecting every step of the process.
Making rice vinegar starts with brewing sake, a cornerstone ingredient. To ensure unmatched quality, Iio Jozo produces their own sake using traditional methods akin to those of Japan’s finest sake breweries. This labor-intensive process requires incredible care: when inoculating rice with koji mold, the team tends to it every 3–4 hours over three days. The fermented rice is then pressed using a hand-powered wooden press. After 45 meticulous days, the sake is finally ready to be transformed into vinegar.
Iio Jozo combines roughly equal parts sake, water, and vinegar mother to ferment the vinegar. The living “good” bacteria in the vinegar mother work slowly, taking about 100 days to ferment the sake into vinegar. But even then, the process isn’t complete. To achieve its signature depth and balanced flavor, Iio-san ages the vinegar for an additional eight months. In total, it takes a full year to produce their rice vinegar—a stark contrast to large-scale industrial producers, who can churn out a batch in just one day.
The result is a rice vinegar that is unparalleled in quality, flavor, and craftsmanship—a testament to Iio Jozo’s enduring commitment to tradition and excellence.