Dry Hopping on a Small Scale: Considerations for Achieving Reproducibility

MBAA TQ http://dx.doi.org/10.1094/TQ-53-3-0814-01 | VIEW ARTICLE
Daniel M. Vollmer and Thomas H. Shellhammer. Department of Food Science and Technology, Oregon State University, Corvallis, OR 97331, U.S.A.
Dry hopping is a technique widely practiced by brewers to add hop aroma to beer. The technique can also be used on a small scale to evaluate the aroma potential of hops in beer. This format has practical uses for hop breeders, brewers, and hop suppliers. Our investigations of small-scale dry hopping have identified a significant amount of variability in the aroma intensity and profile of dry-hopped beers as measured by sensory analysis. A systematic approach at reducing the variability in a pilot-scale dry-hopping process was successful in reducing this variability. This method entailed improved whole-cone hop sampling techniques, increasing the volume of beer that was dry hopped, and blending two single dry-hop events during filtration for a single treatment. In addition to these process changes, oxygen control acted as an appropriate quality assurance strategy and appeared to contribute to the reduced variability in the aroma intensity of dry-hopped beer prepared on a pilot scale. The outputs of this work suggest that small-scale dry-hop evaluations are prone to variability and that simple modifications to account for variation in hops and beer handling can reduce this variability for the purposes of pilot-scale evaluations.

Keywords: Blending, Dissolved oxygen, Dry hopping, Pilot scale, Variability