PURPOSE: To obtain an unpolished rice vinegar with a high acetic acid concentration, by cooking unpolished rice without washing, cooling the cooked unpolished rice, mixing a specific amount of black-KOJI mold, adding water, charging the resultant unrefined vinegar in a pot, naturally fermenting the resultant mixture in the open air, aging the unrefined vinegar in the interior, pressing the unrefined vinegar in a press and filtering the resultant vinegar.

CONSTITUTION: Unpolished rice without washing is cooked and then cooled, 30%, base on 70% unpolished rice, black-KOJI mold is then mixed and 100% water is added to give an unrefined vinegar, which is then charged into a pot, naturally fermented in the open air for 180 days and then aged in the interior for 180 days. The resultant unrefined vinegar is then fed to a press and pressed to give a vinegar, which is filtered through a filter to afford the aimed unpolished rice vinegar with a high acetic acid concentration.