Brewing and Quality Characteristics of Schisandra chinensis Yakju

The objective of this study was to determine the effects of Schisandra chinensis on the alcohol fermentation of Korean traditional rice wine 'Yakju', using various methods including alcohol contents, Hunter's color value, organic acid contents, pH value, and sugar contents. The observed results differed according to dosage and fermentation. The S. chinensis Yakju contained various organic acids such as citric, formic, lactic, malic, oxalic acid, shikimic, and succinic acids. In particular, the citric acid contents of S. chinensis Yakju were 9.22, 161.38, 339.28, 458.97, and 634.96 mg/100 mL at doses of 0, 5, 10, 15, and 20% (v/v) of S. chinensis, respectively. The pH of S. chinensis Yakju ranges from 4.11 to 3.57 according to the ratio of S. chinensis. As a result, the citric acid content and pH of S. chinensis Yakju were dependent on the concentration of S. chinensis. On the basis of the Redness value, the S. chinensis Yakju after fermentation (5.16) was approximately 1.8 times more effective than that before fermentation (2.86) at the concentration of 20% (v/v) of S. chinensis. However, S. chinensis has little or no influence on the sugar and alcohol contents of Yakju. These results indicated that S. chinensis was more efficient for improvement of quality characteristics of Yakju.