The Traditional Brewing Process of Japanese Brown Rice Vinegar

Japanese brown rice vinegar, or genmai-su, is a treasured condiment known for its rich, mellow flavor and health benefits. Made from fermented brown rice, this vinegar is crafted through a time-honored, slow brewing process that emphasizes natural ingredients and techniques passed down through generations.

 The process begins with the selection of high-quality brown rice, which undergoes steaming to soften the grains. This steamed rice is then mixed with koji and water. The koji plays a crucial role, breaking down the rice starches into sugars that will later ferment into alcohol.

 Next, the rice mixture is placed in vinegar fermentation tanks where it ferments for several months. During this period, naturally occurring yeast converts the sugars into alcohol, creating a sake-like liquid. Following this, acetic acid bacteria are introduced, slowly transforming the alcohol into vinegar through a natural fermentation process.

 The vinegar is aged for several months to several years, depending on the desired depth of flavor. This aging process imparts a rich, cereal aroma and smooth, well-rounded taste, making brown rice vinegar a prized ingredient in Japanese cuisine, from salad dressings to sushi seasoning.

Try our brown rice vinegar brewed since the Edo period by Tankaisu, a small business located on the western bank of lake Biwa in Shiga prefecture. This vinegar, made by Fukui-san from locally harvested rice, was fermented for 2 months then subsequently aged for 2 years to reach a mild and smooth taste. This vinegar has won the prestigious Mie Maru prize for quality food in 2021, 2022 and 2023.