The Influence of Hop Harvest Date on Flavor Stability in Dry-hopped Beers

Abstract

The aim of this work was to investigate the influence of hop harvest date on the flavor stability of a dry-hopped lager. The selected harvest dates encompassed a period of 24 days, from a very early (date 1) to a very late (date 5) harvest date. To assess flavor stability, beers brewed with hops harvested at an early date (date 2) and a very late date (date 5) were chosen. The flavor stability of beer is an important criteria of successful brands, and among these, dry-hopped craft beers are being distributed over ever-increasing distances. This is the first study to investigate whether hop harvest date influences the flavor stability of a dry-hopped lager. The results showed that in terms of acceptance ratings beers brewed with late-harvested hops had slightly better flavor stability. However, with increasing storage time and temperature, after 45 days differences in acceptance values decreased and leveled off. Flavor suffered most with increasing storage temperature and time. Also, aroma values decreased with increasing storage temperature and time and showed slightly better ratings for beers brewed with late-harvested hops compared with beers brewed with early-harvested hops when stored at temperatures lower than 28°C. Bitterness quality in stored beer samples was rated higher when beers were brewed with hops from date 5 but only when these were stored at cool temperatures. Consequently, hops that are harvested later seem to support flavor stability but only for a limited time, and this support is more evident when the beer is stored at low temperatures.