Impact of harvest maturity on the aroma characteristics and chemistry of Cascade hops used for dry-hopping

Abstract

The impact of ripening on the dry-hop aroma potential and chemical development of Cascade hops is not well understood. Therefore, 5-6 weekly hop samples were collected over the 2014, 2015 and 2016 harvests. Concentrations of humulones did not change as a function of harvest date, while total hop essential oil content displayed significant positive trends. Concentrations of thiol precursors decreased over harvest while concentrations of free thiols increased. These weekly samples were used to dry-hop an unhopped base beer. Overall hop aroma intensity and citrus quality attributed to beer during dry-hopping increased as a function of harvest date. These results suggest that for brewers to maximize the efficiency of hop usage, early harvested Cascades might be better for bittering, while, later harvested Cascades might be better for dry-hopping or aroma additions because they attributed more intense citrusy aromas to beer and had higher concentrations of free thiols and terpene alcohols.

Keywords: 3-Mercaptohexanol (PubChem CID: 521348); 3-Mercaptohexylacetate (PubChem CID: 17774879); 4-Methyl-4-mercaptopentan-2-one (PubChem CID: 88290); Beer; Dry-hopping; Geraniol (PubChem CID: 637566); Harvest maturity; Hop quality; Humulone (PubChem CID: 442911); Humulus lupulus; Linalool (PubChem CID: 6549); Polyfunctional thiols; Sensory; β-Myrcene (PubChem CID: 31253).