Table of Contents
The impact of diseases on the quality of hops for use in brewing beer
Forster, A., Gahr, A., Schüll, F.
In conventional cultivation, hops must be treated against diseases with pesticides. Since ecological issues complicate approvals and the effectiveness of new products decreases, it is to be expected that not only green cones will be harvested to an increasing extent, but also lots with a visible disease infestation and brown discolored cones. In extensive series of experiments, the effects of a massive infestation with Peronospora, powdery mildew, hop aphid and red spider mite in brown hops that are still marketable were investigated for quality characteristics. Healthy green hops were used for comparison. No significant differences could be found between green and brown hops or hop lots in bitter substances, aroma components and polyphenols. 17 comparative brewing trials showed no differences in the analytical characteristics of the green and brown beers, analogous to the hops. Only in rare cases in very late hopped or dry hopped beers a moderate preference for green hops resulted. Contrary to the general expectations of brewers and the doctrines, no significant defects could be found in beers brewed with massively infested hops.
Descriptors: hops, hop diseases, hop pests, hop quality, beer quality
BrewingScience, 76 (November/December 2023), pp. 133-146
