Development of 100% wheat brewing by optimizing the selection of wheat raw materials and the enzyme composition

Enzymes, Extracts, Other Session
Katsuya Sasaki, Asahi Breweries, Ltd
Co-author(s): Nami Matsumura, Koichiro Takahashi, Kazuhiko Uemura, and Masayuki Aizawa, Asahi Breweries, Ltd., Japan

ABSTRACT: Wheat raw materials give a distinct flavor to beers like Weizen beer. In contrast to barley, which has a husk, the lack of a husk in wheat lengthens the lautering process. For this reason, it has been difficult to raise the proportion of wheat used beyond a certain level. By optimizing the selection of wheat raw materials as well as the enzyme composition, we successfully developed a 100% wheat brewing method (200- and 3,000-L scale), the first of its kind in modern breweries. We report our experience herein. Regarding selection of wheat raw materials, we found that hard (i.e., having a high protein content) whole-meal flour was the most suitable for lautering. As for enzyme composition, we found that a raw material composition of 50% wheat malt and 50% wheat flour greatly affected wort filterability due to cellulase and lipase and that alpha-amylase and protease also play increasingly important roles as the proportion of wheat flour used increases. Based on these findings, we also successfully brewed 100% wheat flour (no malt) beer. In addition, in terms of physical stability, primary gushing was suppressed by increasing protease levels, while haze was suppressed by using proline-specific protease. These types of 100% wheat beer were both brewed using bottom fermentation yeast. Compared to 100% barley beer, the flavor components of 100% wheat beer were characterized as being high in isoamyl acetate and low in astringency-conferring components hordatinA and polyphenol.

Katsuya Sasaki is a research worker at the Research & Development Laboratories for Brewing, Asahi Breweries, Ltd. in Ibaraki, Japan. He received his M.S. degree in engineering from the Tokyo Institute of Technology in 1998 and joined Asahi Breweries, Ltd. He has researched malting and brewing technology.