Production and characteristics of sprouting rice wine

Abstract

Rice grain (Oryza sativa var. Japonica, Reiho) was soaked in running water overnight and incubated at 25°C for 7–8 d to prepare sprouting rice. A novel and/or ancient alcoholic beverage designated as sprouting rice wine was properly made from various starchy materials using sprouting rice powder as a saccharifying agent. Sprouting rice wine containing 9–15% (v/v) ethanol had a characteristic aroma just like Japanese sake and a rather sour taste as judged by organoleptic testing. The rice wine was colorless or faintly yellow and the acidity was around 5.0. Larger amounts of volatile compounds such as higher alcohols and esters were found to be contained in the rice wine by gas chromatographic analysis. As the starchy materials fed to the initial mash were increased, the amounts of ethanol and dextrin contained in the rice wine also increased, and the quality of the rice wine was improved. Though the origin of ancient Japanese sake is still unclear and the evidence for the production of sprouting rice wine in ancient times is insufficient, the legendary and mysterious alcoholic beverage of antiquity made with sprouting rice was reproduced.