Quality Changes during Alcohol Fermentation of Takju Using Oat

Abstract

In this study, the effect of the amount of water added during fermentation on the quality of takju was investigated. Takju was made by adding water 2-fold (OT-2), 3-fold (OT-3), and 5-fold (OT-5), respectively, of the rice weight (w/w). The pH decreased until the 3rd day of fermentation and was maintained in the range of 4 to 4.5 until the end of the fermentation, and the 5-fold water stasis was the lowest. Acidity and brix degree were higher in 5-fold malt, and the final acidity at the end of fermentation was 0.4% for 2-fold malt, 0.39% for 3-fold and 0.32% for 5-fold malt. The alcohol content was the highest on the 5th day of fermentation, 9% for 2-fold, 8.4% for 3-fold and 7.4% for 5-fold malt. The yield of oat takju, adjusted to 6% considering the alcohol content of commercially takju, was the highest with 5-fold water content. Considering the amount of water, 5-fold hydrous takju showed faster saccharification and alcohol production.