Examination on aging on sake and shochu at 3 different spots (0°C, mountain area and room temperature in Tokyo)

We investigated the change in compositions of various alcoholic beverages which were stored for 5 years at 3 different conditions, low temperature at 0°C in a refrigerator, in a mountainous area (Hirata village, Fukushima prefecture) and at room temperature in Tokyo. Four types of sake and 4 types of shochu were used in our investigations. (1) Surveying the weather of the mountainous area throughout the year, the average of air atmospheric temperature was 11.4°C, the humidity was 71.9%, and the amount of a rainfall was 94.6 millimeters for a month. (2) Direct reducing sugar (DRS), acidity and amino acidity in sake were decreased, whereas pH and coloring degree were increased year by year. Those changes of sake stored in the mountainous area was midway between those at low temp. and room temp. conditions. Those values of junmai-shu in sake changed greatly, especially ferricicyanide reducing substance (FRS), 3-deoxyglucosone (3-DG), coloring degree and furfural increased rapidly in 3-5 years. (3) In shochu, the change of each component was smaller than those of sake, but a decrease of esters and aldehyde was observed. In the mountainous area, the change in components of shochu were midway between those of two conditions, the same as sake. (4) Sensory evaluation on alcoholic beverages aged in 3 different conditions was done by 12 panels. As a result, all sake and almost all of the shochu aged in storehouses in the mountainous area were given significant estimation. Therefore storage in the mountainous area was considered to be the most suitable for sake and shochu.