Soju is a Korean traditional distilled alcoholic beverage produced from mashes various crops and Nuruk which is cultured with wild microorganisms. This study was conducted to investigate rice-Soju brewing characteristics of yeasts isolated from Korean traditional Nuruk. The general components of rice (Hanarumbyeo) raw materials were 14.7 g of water, 6.8 g of crude protein, 0.9 g of crude lipid, 0.4 g of crude ash, and 76.5 g of carbohydrate in 100 g. Saccharifying and proteolytic activities in Hanarumbyeo ipguk (solid-state culture of Aspergillus luchuensis) were also determined. The alcohol content of the fermented wash from isolates was 15.37-16.58% (v/v), which is 16.7-36.0% higher than that of industrial yeasts (12.33-13.19%). Reducing sugar contents were 2.04-3.92 and 7.92-8.78 g/100 mL in the isolates and industrial yeasts, respectively. The isolated yeasts showed 25.2-52.7% higher yield of distillates (41% alcohol) compared to industrial yeasts. Forty-one components were detected in the rice distillated Soju (25% alcohol) and principal component analysis revealed differences between the isolated and industrial yeasts with respect to the contents of i-BuOH, isobutanal diethyl acetal, ethyl caprate, and tetradecanoic acid.

• 최한석(농촌진흥청 국립농업과학원 발효식품과) | Han-Seok Choi (Fermented Food Science Division, National Institute of Agricultural Sciences, RDA, Wanju 55365, Korea) Corresponding author
• 강지은(농촌진흥청 국립농업과학원 발효식품과) | Ji-Eun Kang (Fermented Food Science Division, National Institute of Agricultural Sciences, RDA, Wanju 55365, Korea)
• 정석태(농촌진흥청 국립농업과학원 발효식품과) | Seok-Tae Jeong (Fermented Food Science Division, National Institute of Agricultural Sciences, RDA, Wanju 55365, Korea)
• 김찬우(농촌진흥청 국립농업과학원 발효식품과) | Chan-Woo Kim (Fermented Food Science Division, National Institute of Agricultural Sciences, RDA, Wanju 55365, Korea)
• 백성열(농촌진흥청 국립농업과학원 발효식품과) | Seong-Yeol Baek (Fermented Food Science Division, National Institute of Agricultural Sciences, RDA, Wanju 55365, Korea)
• 여수환(농촌진흥청 국립농업과학원 발효식품과) | Soo-Hwan Yeo (Fermented Food Science Division, National Institute of Agricultural Sciences, RDA, Wanju 55365, Korea)