2017 Master Brewers Conference
79. Development of a low carbohydrate beer using a high alcohol wort

Takuya Ohashi, Asahi Breweries, Ltd., Moriya-shi,Ibaraki, Japan


The market of low carbohydrate beer is expanding due to the growing need for health-conscious products. In Japan, low-carb or low-purine beers, called functional beers, launched in 2002 and these beer sales account for more than 20% of all beer in 2015. There are two normal methods to make low-carb beer. One is a raise the fermentation degree by prolonging saccharification time or using many enzymes. The other is to dilute maximally during the filtration process. Therefore, these beers are watery and have little body taste because of the low alcohol. One of the big improvement points that became clear from our customer research of low-carb beers was the alcohol concentration. Customers needed alcohol content above 4.0 v/v% of alcohol (ABV). This is why we developed the new low-carb beers that have 6.0% ABV by innovative technology. First, we examined saccharification conditions and enzyme combinations to get a wort with as high a fermentation degree as possible. The results showed the fermentation degree derived from malt was over 104% in the most suitable conditions. Moreover, we were able to raise the fermentation degree by using sucrose together. But it was difficult to achieve 6.0% ABV with only these methods. Next, we focused on a technology of Japanese sake that adds distilled alcohol to the sake lees to control the aroma and taste. We installed equipment capable of sampling the fermenting beer at four different heights of the cylindroconical tank and investigated the influence of fermentation using a high-alcohol wort that added the distilled alcohol to the wort. Surprisingly, the addition of alcohol did not inhibit the consumption of sugars. On the other hand, the low cell viability at the early stage of fermentation, the low yeast growth rate, and the sharp decline in the amount of yeast after 96 hours of fermentation were confirmed. Also, a rise of differential pressure occurred in the filtration process. It was presumed that the microparticles were generated by protein denaturation due to contact between the protein in the wort and highly concentrated alcohol. We could solve it by passing the yeast through a separator after maturation. This high-alcohol and low-carb beer was launched in 2015. The shipment in the first year reached 460,000 kL, and it can be expected to further increase sales this year.

Takuya Ohashi graduated from the Department of Applied Molecular Biology in the Graduate School of Biostudies at Kyoto University, Japan. He joined Asahi Breweries, Ltd., in 2009 as brewing staff in their Kanagawa brewery. After he had worked in the brewing technology section of the brewing laboratories, he has been engaged in research and development of beer in Development Laboratories for Alcohol Beverages at Asahi Breweries, Ltd., since 2016.

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