Effect of grain raw materials on the quality characteristics of ‘Kaoliang’ spirit

Abstract

This study was carried out to investigate the quality characteristics of 'Kaoliang' spirit by grain materials for developing the Korean-style 'Kaoliang' spirit. Each grain was crushed for solid fermentation, and re-fermentation was performed three times in total. There was no significant difference in temperature during solid fermentation by different grains, but it rose to up to 31℃ until the first two days of fermentation, and then the fermentation was completed while maintaining 27℃. Agglomeration occurred in solid fermentation using wheat, resulting in lower work efficiency than other grains. The total acids increased after fermentation, and was the highest at 0.77% in distilled spirit using sorghum, and the major organic acids were lactic acid and acetic acid. A lot of glycerol and glucose were detected, and after three re-fermentation, all sugars were converted to ethanol. Through three re-fermentation, ethanol was the highest in distilled spirit using corn and barley. The volatile compounds, ethyl acetate, ethyl butyrate, and ethyl lactate, were detected at the high level in distilled spirit using sorghum, and the highest ethyl caproate component in using wheat. Therefore, this study proposed to use the mixed grain materials, sorghum and wheat, in order to increase the production of ethyl caproate, the main aroma compound in 'Kaoliang' spirit.