Linjiang Zhu (1); (1) Jiangnan University, Wu xi, China
Yeast, Fermentation, and Microbiology
Starch-rich raw materials are widely used as adjuncts in high-gravity beer brewing due to the fact that they are inexpensive and abundant and have high fermentability; they also are suitable for production of light beer. Rice and corn starch are the most common adjuncts in China. In recent years, the yield of degermed corn grits rapidly increased, and it is thought to be an alternative beer-brewing adjunct. However, brewing characteristics of corn grits and their impact on beer flavor and taste should be evaluated. In this study, the effect of particle size of corn grits and fatty acid content was evaluated, and the flavor compounds in the final product were analyzed. The results indicate that degermed corn grits within the range of 900-600 µm can be used as a beer-brewing adjunct. The flavor and taste of corn grits beer are similar to that of rice beer based on flavor compound analysis and tasting tests. However, the contents of fat and fatty acids in demerged corn grits will influence beer flavor and aging due to a continuous increase of its content during storage. We suggest that the content of fat should be controlled below 1%, and the content of fatty acids should be controlled below 80 mg/100 g.
Linjiang Zhu received a Ph.D. degree in microbiology from the Institute of Microbiology, Chinese Academy of Sciences in Beijing, China. He began work in Jiangnan University in August 2012 as a lecturer. He is also a researcher in the Laboratory of Brewing Sciences and Technology of Jiangnan University. His research interests include brewing technology and traditionally fermented foods.