Naturally brewed Oumiseki Brown Rice Vinegar is manufactured with great care in its entirety in the company’s brewery. This includes the making of the sake used as the ingredient, in which organic Ikimono-tanbo rice directly sourced from local farmers is prepared with brewing water, spring water from the Hira Mountains, over an extended period of time. The in-house fermentation process of vinegar takes approximately two months, as brown rice is saccharified, alcohol fermented and acetic acid bacteria is added. Even after the vinegar is produced, it is matured for around two years, with absolutely no added seasoning, preservatives or flavoring. Typically, when vinegar is made from sake, the rice is milled and so proteins and vitamins are discarded. However, since this product is made from brown rice, the proteins, vitamins and minerals are not lost, and the resulting vinegar is very mild and smooth in taste.
Tankaisu is the sole local vinegar brewery in Shiga Prefecture, focusing on the production of naturally brewed vinegar made with sake through static fermentation, reproducing the manufacturing method found in old documents from the Edo period (1603-1867).