The influence of pectolytic enzymes and their use in the brewhouse.

Keininger, H. and Parsche, I.

Abstract
Glucanases can be produced from the Aspergillus Niger fungi species, and they can be added to the mash in various amounts as raw enzymes. In this manner, hemicelluloses and gums can be degraded with the following advantages: 1. An undermodified malt can be partly utilized in the mash so that the originally existing amylases can better degrade the starch. This results in a higher extract. An additional increase in the extract is due to the low-molecular carbohydrates produced through the degradation of beta-glucan. 2. The viscosity of the first wort and the sparge decreases, resulting in reduced run-off times and a better extraction. 3. A fraction with a high gum content causes a hanging fermentation. This drawback can be avoided through an intensive degradation of gums. The propagation of the fungi was carried out on a so-called deficient substrate which contained starch without the low-molecular carbohydrates. A mixture of barley grist, malt germ, wheat flour as well as the dried apple pulp with some trace elements served as the substrate. The mashing experiments, carried out with undermodified and well-modified malts as well as with the addition of up to 30% of raw barley, confirmed the above advantages. On the negative side, some darkening of the finished wort was observed but this could be offset by adding barley to the mash. The taste tests of the beers produced did not show any difference vs. control beers and the foam stability of the beers was unchanged.
Keywords: brewing fungi beta-glucanase mashing pectinase use of enzymes