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O-3. The influence of decoction mashing procedure on beer characteristics

Presenter: Yusuke Ishizuka, Suntory Liquors Limited, Osaka, Japan
Coauthors: Taichi Maruhashi, Yoshinori Hida, and Kaneo Oka, Suntory Liquors Limited, Osaka, Japan

Nitrogen compounds in mash contribute not only to beer taste and foam quality, but also affect the brewing process, provide the nitrogen source for yeast fermentation, and can affect beer filterability. Therefore, the control of protein modification during malting and mashing is very important, and we must consider optimizing the mashing procedures depending on malt quality, and vice versa. It has become popular to use malts with relatively high protein modification because they are both easy to use and economical. However, this may cause low fullness or an unpleasant aftertaste if the mashing method is not carefully considered. At the MBAA Annual Conference in 2010, we reported that decoction beer had better fullness and bitter quality than infusion beer when relatively low protein modified malt was used. At WBC 2012, we reported that the components of nitrogen compounds present in mash could also be controlled by the decoction mashing procedure (mashingin temperature, rest temperature, or rate of temperature increase) and that, based on these results, it appears that high molecular weight nitrogen compounds are a good indicator of bitter quality and foam cling. As mentioned above, decoction mashing procedure influences beer characteristics when relatively low protein modified malt is used. Furthermore, the mashing procedure used after decoction may also change the degradation of nitrogen compounds and affect Maillard reaction products at the mash and wort boiling stage. In this study, we investigate the influences of mashing temperature, before and after the addition of decoction mash to residual mash, and discuss the effects of mashing procedure on beer characteristics, focusing on nitrogen compounds and Maillard reaction products that result from enzyme reactions during the mashing process.

Yusuke Ishizuka graduated with a master’s degree in environmental studies from the University of Tokyo in 2011. After joining Suntory, he worked for two years in the Beer Development Department of Suntory Liquors Limited.