Irie, T., Asahi Breweries, Ltd., Moriya, Ibaraki, JAPAN, Noba, S., Asahi Breweries, Ltd., Moriya-shi, Ibaraki, JAPAN and Kobayashi, M., Asahi Breweries, Ltd., Research Laboratories for Alcohol Beverages, Moriya-shi, Ibaraki, JAPAN
Technical Session 3: Analytical Flavors
Monday, June 05, 2017
8:30–10:15 a.m.
Caloosa Ballroom
There are a number of studies reported by Japanese breweries on technological developments for the control of sulfur off-flavor components in beer. These technologies have been necessary to allow the brewing of low-malt beer with low nutrients, such as amino acids, in the wort, which has a lower tax rate than normal beer under the Japanese Liquor Tax Law and are also important to increase the “clearness” and “smoothness” of products, which are preferred by Japanese consumers. We have also reported some technological results in this field. These include both analytical technologies to detect and quantify the off-flavor components, even at low concentrations, and production technologies to control the formation of these components in the brewing process through the introduction of analytical methods to monitor the process. As one of such sulfur components, we focused on 2-mercapto-3-methyl-butanol (2M3MB). It imparts an unpleasant onion-like flavor to beer, and variations in the amount were observed among several breweries, which may lead to sensory variations. Recently, we purified the precursor of 2M3MB from hops and identified the compound as 2,3-epoxy-3-methyl-butanal (EMB). By monitoring 2M3MB and EMB in the brewing process, we found variability in both the amount of EMB in wort and the conversion rate of EMB to 2M3MB among several of our breweries. In this presentation, we discuss further monitoring of the brewing process. We monitored the levels of EMB from the start of boiling to the start of fermentation at two breweries (1,250 and 700 hL/brew) with documented variability in 2M3MB. The precursor was detected from hop dosing at the start of boiling and increased through the boiling, whirlpool, and aeration processes. This supports the hypothesis that 2M3MB is derived from hops and that the uptake of oxygen is involved in its formation. In addition, differences between the two breweries were observed, particularly in the initial boiling step and in the whirlpool waiting phase. Differences in the brewing process and equipment that may cause variations between the breweries will also be discussed. The results may provide a clue to determine the underlying reasons for variations in 2M3MB production and may allow us to improve our processes to control the amount of 2M3MB in beer.
View Presentation
