Reproduction of Rice Vinegar Production Method as Described in the Books from the Edo Period

Abstract

Thirty-three rice vinegar production methods were obtained from 16 books dating back to the Edo period and earlier. The rice vinegar production methods of the Edo period were characterised by a remarkably lower water: materials ratio (volume percentage of water relative to rice and koji) than that employed in the modern times. Furthermore, vinegar production was restricted to summer season, and required a short preparation period of approximately one week to one month. The reproduction test of rice vinegar was conducted at a vinegar manufacturing company that had been producing traditional rice vinegar since the Edo period; the procedures followed were that described in the books from the Edo period. Currently, the water: materials ratio used is approximately 300%. However, when the water: materials ratio was 100-250% as described in the Edo period books, lactic acid fermentation occurred and the ethanol content increased to as high as 9-13 g/ 100 ml during the initial stage of preparation, but acetic acid fermentation was not observed. This suggests that throughout the Edo period, the fermented lactic acid products containing 1-2 g/100 ml lactic acid were obtained via rice vinegar production method and used as vinegar.