Organic Acids of Commercial Beers in China: A Chemometric Study. Yin Li (1), Department of Plant Science, Yingying Xu, Department of Cereal and Food Science, and Paul B. Schwarz, Department of Plant Science, North Dakota State University, Fargo; and Guoxian Gu, School of Biotechnology, Southern Yangtze University, Wuxi, P.R. China. (1) Corresponding author. E-mail: <Yin.Li@ndsu.edu>; Phone: +1.701.231.7732; Fax: +1.701.231.7723. J. Am. Soc. Brew. Chem. 65(2):86-91, 2007.

The concentration of six organic acids (acetic acid, lactic acid, pyruvic acid, malic acid, citric acid, and succinic acid) and pH were determined in 45 beer samples (23 from China and 22 from other countries) with the intention of associating the “moderate to very sour” character of Chinese local beers with particular acids. The content of acetic, lactic, and total organic acids in Chinese lagers was significantly higher, while citric acid was much lower, than that of foreign brands (P < 0.05). Using discriminant analysis, both stepwise and with all variables included, moderately strong classifications were obtained using the magnitude of the original gravity (low, medium, and high), the origin of the beer (Chinese or foreign), and the sourness intensity (slightly, moderately, and very sour) as the classification categories. These analyses supplied more information about organic acids in beer and its associated effect on the properties of lager beer. Keywords: Chinese beer, Multivariate analysis, Organic acids, Sourness