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.

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单级和两级干跳法的比较

摘要 多级干式啤酒花是酿酒商广泛采用的一种技术，使啤酒具有浓郁的啤酒花香气。然而，在已发表的文献中不存在对其功效的彻底分析。本研究的目的是比较在相同累积速率下通过单级或两级干投生产的啤酒的特性。在中试规模 (80–100 L) 中，使用 Centennial 啤酒花，将未加酒花的基础啤酒以 386、772 和 1544 g/hL 的浓度交替添加单级或两级干酒花。使用 Amarillo、Simcoe、Cascade、Citra 和 CTZ 颗粒的组合，单独的商业啤酒（~350 hL 批量）以 733 g/hL 的单级或两级添加干酒花。中试规模的干酒花啤酒显示出残留提取物、pH 值、苦味单位、腐殖质酮和总多酚的增加，随着啤酒花剂量的增加，异α-酸会减少。苦味单位、腐殖质酮和异α-酸的变化似乎在两级干啤酒花啤酒中更为明显。相比之下，商业啤酒在化学成分方面几乎相同。作为中试规模处理中的两阶段干酒花的结果，观察到由训练有素的小组衡量的六种香气属性显着增加。观察到使用两阶段添加制成的商业啤酒的香气潜力略有增加，尽管这些差异在统计上并不显着。这些结果说明了多级干酒花添加对啤酒香气的影响，并为酿酒商提供指导，以考虑多级干酒花是否可以产生理想的结果，同时可能使用更少的酒花材料。