Control of Glucanolysis in Mashing

Abstract

Malt always contains small amounts of β-glucans, which may cause problems either in lautering or in beer filtration. The effects of mashing variables on the solubilization and hydrolysis of β-glucans were studied both on a laboratory and an industrial scale. Well- and poorly modified malts produced from the two-row barley varieties Kustaa and Kymppi were used. In addition, the use of unmalted barley as an adjunct was studied. The optimum mashing-in temperature for glucanolysis was 48°C. Starch gelatinization and other heat-induced structural changes in the coarse grist particles seemed to contribute to the solubilization of β-glucans at high temperatures. By extension of the mashing-in period, the majority of the β-glucans from unmalted barley could be hydrolyzed by the malt β-glucanases. Trials on an industrial scale showed that the mash tun design and the efficiency of stirring and heating have a marked effect on the release and hydrolysis of β-glucans. The effects of the mashing variables on the β-gluc...