Record Details
Effect of Harvest Maturity on the Chemical Composition of Cascade and Willamette Hops
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | Effect of Harvest Maturity on the Chemical Composition of Cascade and Willamette Hops |
| Names |
Sharp, Daniel C.
(creator) Townsend, M. Shaun (creator) Qian, Yanping (creator) Shellhammer, Thomas H. (creator) |
| Date Issued | 2014 (iso8601) |
| Note | This is an author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by the American Society of Brewing Chemists and can be found at: http://www.asbcnet.org/publications/journal/Pages/default.aspx |
| Abstract | Considerable expertise is required to grow high-quality hops, and brewers and hop growers alike have a common goal of obtaining the highest quality hops possible. Change in the chemical composition of hops during plant maturation is a dynamic process requiring a comprehensive chemical and sensory analysis in order to maximize the characteristics of interest to brewers. The effect of harvest date, location, and cultivar on key chemical components of Willamette and Cascade hops was investigated for the 2010 and 2011 growing seasons. Hops were harvested at 3 time points (Early, Typical, and Late), within a 3-week interval from 2 different farms in the Willamette Valley, Oregon. A split-plot experimental design for each cultivar was used; each farm represented a main plot and harvest years were designated as subplots. American Society of Brewing Chemist standard methods of analysis were used to measure moisture content, hop acids and their homologs, hop storage index, total essential oil content and volatile profile by GC-FID. Additionally, difference testing, descriptive analysis, and consumer acceptance testing was conducted using beers brewed with either Typical or Late harvested Cascade hops from the 2010 harvest year. The response of analytes was dependent on the cultivar being examined, its location within the Willamette Valley, as well as timing of harvest. Hop acids did not change appreciably during plant maturation for the period examined, while hop oil content increased. Increases in oil quantity were strongly correlated (r > 0.90) with increases in α-pinene, β-pinene, myrcene, limonene, methyl heptanoate, and linalool concentrations. Clear sensory differences were found between beers brewed with Typical and Late harvested Cascade hops using triangle testing, consumer preference testing, and descriptive analysis. |
| Genre | Article |
| Topic | Aroma, |
| Identifier | Sharp, D. C., Townsend, M. S., Qian, Y., & Shellhammer, T. H. (2014). Effect of Harvest Maturity on the Chemical Composition of Cascade and Willamette Hops. Journal of the American Society of Brewing Chemists, 72(4), 231-238. doi:10.1094/ASBCJ-2014-1002-01 |
