Scale‐up of Dry Hopping Trials: Importance of Scale for Aroma and Taste Perceptions

Abstract

In this study beers that were dry hopped in three different batch sizes were compared. The hop-oil concentrations were measured and possible aroma-active hop volatiles were identified in the hop pellets as well as in the beers. The analytical results were correlated with the tasting results from a trained tasting panel. Mass transfer rates were not comparable between the different scales, and significant differences could be detected by the tasters. The beers dry hopped on an industrial scale are not comparable in flavor and odor to those dry hopped on a laboratory scale.

Studies on the odorant concentrations and their time dependencies during dry‐hopping of alcohol‐free beer

“…10 In a laboratory-scale experiment, also a decline in the myrcene concentration was observed between days 1 and 7. 32 In contrast, Wolfe et al showed almost constant concentrations of linalool and myrcene during a dry-hopping period of 7 days. 33 For all analysed esters, transfer rates up to 91%, referred to the concentrations in hops, were obtained during the first 2-3 days (Figure 2).…”

“…30,31 A quite similar course of the curve for linalool and geraniol was already shown for dry-hopped alcoholic beer in different production scales. 32 In a semi-industrial scale, a maximal transfer of linalool and geraniol in the first 24 hours and a slight decline of the concentrations in the following days were reported. 32 An increase of geraniol concentration at the end of the dry-hopping period can be attributed to the use of the hop variety Mandarina Bavaria, that has been shown to have high contents of geranyl acetate, acting as geraniol precursor.…”

“…32 In a semi-industrial scale, a maximal transfer of linalool and geraniol in the first 24 hours and a slight decline of the concentrations in the following days were reported. 32 An increase of geraniol concentration at the end of the dry-hopping period can be attributed to the use of the hop variety Mandarina Bavaria, that has been shown to have high contents of geranyl acetate, acting as geraniol precursor. 10 In a laboratory-scale experiment, also a decline in the myrcene concentration was observed between days 1 and 7.…”

“…The present study was the first on the time dependency of the aroma transfer during dry-hopping of alcoholfree beer, while this issue has already been examined in alcoholic beer. 32,33 It was shown that a longer contact time does not necessarily increase the transfer of linalool, myrcene, or geraniol into F I G U R E 4 Sensorial doseresponse relationship of geraniol, (R)-linalool, and myrcene (A) and of ethyl 2-methylbutanoate, ethyl 3-methylbutanoate, ethyl methylpropanoate, (S)-methyl 2-methylbutanoate, and (S)-propyl 2-methylbutanoate (B; black odour descriptors related to all esters, coloured odour descriptors are related to the specific esters) in alcohol-free beer.…”

Dynamics of Isomerization of Hop Alpha-Acids and Transition of Hop Essential Oil Components in Beer

“…The CO 2 produced during alcoholic fermentation also affects the decrease of aroma compound yields in beer. [5][6][7][8] To avoid the loss of aroma constituents and to achieve better yields dry hopping technique is in use, where hops are added at a later stages of brewing process, during fermentation or maturation.…”