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2017 Master Brewers Conference
35. Innovative malting process involving acidic steeping

Masako Sawada, Suntory Beer Limited, Osaka, Japan

Coauthor(s): Sotaro Tatsu, Research Institute, Suntory Global Innovation Center Limited, Kyoto, Japan; Yusuke Usami, Safety Science Institute, Suntory MONOZUKURI Expert Limited, Kyoto, Japan; Xiaoyuan Shan, Suntory Beer Limited, Osaka, Japan

Malt and Grains II
Friday, October 13
10:00–11:45 a.m.
Imperial Salon B

Malt specification such as degree of cell-wall degradation (modification) and degree of proteolysis (KI) affects the taste of beer. Our previous study indicated that extremely high or low levels of both modification and KI lead to an undesirable taste in the final product. However, a combination of high degree of modification and moderate suppressed KI afforded beer with a pleasant fullness. Thus, high modification and low KI are ideal specifications for the malt. However, a positive correlation exists between modification and KI. We therefore evaluated various techniques to produce malt with high modification and low KI, thereby developing an innovative process to replace the conventional malting methods. The various parameters evaluated for the production of malt with high modification and low KI were pH and temperature of the steeping solution, and gas atmosphere, light conditions, and temperature used during the germination process. The results indicated that malt without root could be obtained by steeping barley in aqueous phosphoric acid solution of pH 2. Despite the absence of roots, the malt was found to retain its enzyme activity for cell-wall degradation, protein degradation, and starch degradation, which is unusual in the physiological state of the plant. Acidulation of steeping water inhibits the growth of roots, thereby curbing malting loss; hence, the recovery rate of malt production was 4% higher than that obtained with normal steeping. In addition to yield improvement, the amount of undesirable β-glucan in beer brewing was markedly reduced and proteolysis was suppressed to a moderate extent. The beer obtained from our innovative malting process involving acidic steeping has better fullness than that obtained in normal processes, without any unpleasant and bitter aftertaste. Hence, our method can be an excellent comparison to conventional methods of malting.

Masako Sawada is a member of the Beer Development Center for Liquors in Suntory Beer Limited. She graduated from Kyoto Prefectural University in the Faculty of Agricultural Chemistry and then joined Suntory in 1979. From 1987 to 1992, she was engaged in the development of functional oligosaccharide in the Institute for Fundamental Research, and she won an award from Japan Soft Drink Association in 1994 in recognition of her achievement. From 1992 to 2010, she was engaged in the improvement of beer flavor stability in the Beer Development Department. From 2011 to 2016, she worked on Research Institute, Suntory Global Innovation Center Limited, engaged in extracting value of the raw materials such as algae, coffee, barley, and so on.

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