A Comparison of Single-Stage and Two-Stage Dry-Hopping Regimes

Abstract

Multi-stage dry-hopping is a technique that is widely used by brewers to achieve intense hop aroma in beer. However, a thorough analysis of its efficacy does not exist in the published literature. The goal of this study was to compare the properties of beers produced by single or two-stage dry-hopping at the same cumulative rate. On the pilot scale (80–100 L), an un-hopped base beer was subjected alternately to single- or two-stage dry-hop additions at 386, 772, and 1544 g/hL using Centennial hops. Separately commercial beers (∼350 hL batch size) were dry-hopped at 733 g/hL in single or two-stage additions using a combination of Amarillo, Simcoe, Cascade, Citra, and CTZ pellets. Pilot scale dry-hopped beers showed increases in residual extract, pH, bitterness units, humulinones, and total polyphenols, accompanied by a decrease in iso-α-acids with increasing hop dose. Changes in bitterness units, humulinones, and iso-α-acids all appeared to be more pronounced in the two-stage dry-hopped beers. In contrast, commercial beers were nearly identical in terms of chemical composition. Significant increases in six aroma attributes scaled by a trained panel were observed as a result of two-stage dry-hopping in the pilot scale treatments. Slight increases in aroma potential were observed for the commercial beer made with two-stage additions, although these differences were not statistically significant. These results illustrate the impact multi-stage dry-hop additions have on beer aroma, and provide direction to brewers to consider whether multi-stage dry-hopping may yield desirable results while potentially using less hop material.

Keywords:

• Dry-hopping
• beer
• Humulus lupulus
• efficiency
• hop aroma
• multi-stage dry-hopping

Acknowledgements

The authors would like to thank Brad Barnette and Crosby Hop Farms for providing hop material for this study, and Jeff Edgerton and BridgePort Brewing Company for producing the un-hopped beer. The authors would also like to acknowledge the support of Russian River Brewing Company.

Disclosure statement

No potential conflict of interest was reported by the author(s).