Kakishibu (fermented unripe persimmon juice)

Kakishibu is a natural dye and preservative obtained by fermenting the juice of unripe astringent persimmons. It is typically made by crushing green persimmons, adding water, sealing the mixture and letting it ferment for several days, then filtering it and storing the clear liquid in a sealed container for about six months. In sake brewing, kakishibu is sometimes used together with gelatin in the fining process (called oridarami-sage or kasumi-sage, in which suspended particles are settled out to clarify the sake). Thanks to its distinctive flavor and components, it plays an important role in giving sake a clear quality. Because kakishibu also has antibacterial properties, it can be expected to improve the shelf life of the product as well.