O-12
Effect of subcritical water treated malt on beer quality
Presenter: Koji Nagao, Suntory Ltd, Kawasaki, Japan
Co-Authors: Koichi Nakahara, Takako Inui, and Nobuyuki Fukui, Suntory Ltd, Osaka, Japan

We have been developing industrial applications of subcritical-water for malt treatment. We presented in World Brewing Congress 2004 that we conducted malting trials, and several kinds of flavor and aromatic compounds were generated in a few minutes. We tried to make wort by using subcritical-water malt with 180°C/1 min, and melanoidin malt, and then compared components in each wort. As a result, it was confirmed that lipids and fatty acids in wort using subcritical-water malt were reduced as compared to wort using melanoidin malt. In this presentation, we tried to brew using the subcritical-water malt we developed last year. In brewing trials, we used subcritical-water malt and untreated malt and then conducted a comparative evaluation of each beer. In consequence of brewing trials, advantages of subcritical-water malt beer were shown not only in improving beer flavor by sensory tests but also in flavor stability by ESR analysis of beer stability and by trans-2-nonenal analysis. Consequently, by industrial applications of subcritical-water for malt treatment, we succeeded in reducing the generation of deterioration products during the brewing process and improving beer flavor and flavor stability significantly.

Koji Nagao received his M.S. degree in chemical engineering from Kyoto University in 2000. He majored in process systems engineering, where the systematic methodology for realizing an advanced production system producing a competitive product with saving resources and energy system is investigated. He joined the Process Development Department, Suntory, Ltd., in April 2000 as a chemical engineer for improving process of products. He has been working in the field of applied supercritical-water technology since January 2002, and developing beer and material processing technologies since January 2004. He is a member of the Societies of Chemical Engineers, Japan.