O-16
Analysis of sulfur compounds in beer and happo-shu
Presenter: Yuji Kurokawa, Kirin Brewery Co., Ltd
Co-Authors: Sachio Iinuma, Kaori Fukano, Yuki Narita, Tetsuji Yasui, and Motoo Ohkochi, Kirin Brewery Co., Ltd

Due to their low olfactive thresholds and unpleasant odor, sulfur compounds strongly impact the taste of beer and happo-shu. Accordingly, we conducted analyses of 14 sulfur compounds (H(2)S, DMS, methanethiol, etc: eight known and six unknown compounds) for the ultimate purpose of learning means for controlling sulfur compounds in beer and happo-shu. As a result of our analyses of various beer products, we discovered that all-malt beer contained high levels of dimethyltrisulfide and methionol, while happo-shu contained high levels of H(2)S and methanethiol. Meanwhile, beer brewed with adjuncts showed lower overall levels of sulfur compounds. Given these results, we have concluded that levels of sulfur compounds vary according to type or category of product. Even within the same category, we show that differing brands and extensions within the same brand contain different levels of sulfur compounds. Furthermore, subjecting samples to accelerated aging resulted in marked increases in H(2)S, methanethiol, etc., while other types of sulfur compounds showed different behavior. We also demonstrated that changing wort composition via changes in malt ratio has an effect on sulfur compound levels in beer and happo-shu.

Yuji Kurokawa graduated from Osaka university in 1997 with a master degree in biotechnology and joined Kirin Brewery Company Limited in the same year. He worked in Toride Brewery from 1997 to 2003. Since 2003, he has worked in the Research Laboratories for Brewing.