A recently released report confirms what brewers have always known. Hops are impacted by terroir. For instance, Mosaic hops grown in Oregon’s Willamette Valley are not the same as Mosaic hops grown in Washington’s Yakima Valley. A particular variety of hop will exhibit different characteristics depending on exactly where it was grown and the conditions under which it was grown. The report from researchers working with the University of Oregon recently validated and explored the concept of hop terroir.
Hop Selection is a Noun and a Verb
The report helps explain why hop selection is such a big deal. Maybe you’re not yet familiar with the term hop selection. I’ve heard the term used in both its noun form and verb form. In short, hop selection is a part of the harvest season. It’s a time of year and it’s an activity. Brewers from across the country and around the world converge on hop-growing regions to carefully examine the year’s crop and select exactly which hops they’ll purchase for the upcoming year.
For the brewers, it’s not so simple as deciding which hop varieties they want to use. Rather, it’s about selecting exactly which Mosaic, Citra, Centennial, or Cascade hops they want to use. From which farm? From which lot? Early harvest? Late harvest? All of it may depend on that year’s growing season. Was it wet or dry? Hot or temperate? There are a lot of variables that impact the deepest essence of the hops.
Beer drinkers, even hardcore IPA aficionados, might question whether one bunch of Centennial hops is different from the next, but brewers have long held that there is variation and, even if that variation is subtle, it impacts the beers they produce. In that regard, hops are not too different than wine grapes: terroir matters.
“Like winemakers, brewers want to know: Will hops grown in different regions be different? And, if so, why?” said Tom Shellhammer, an Oregon State professor who studies the chemistry of hops. “This study shows compelling evidence that there are differences you can attribute to the region.”
Not Better, Just Different
According to a press release introducing the study, the researchers analyzed Cascade and Mosaic hops from the 2020 harvest year grown at 39 different locations in Oregon’s Willamette Valley and Washington’s Yakima Valley, two of the nation’s leading hop-growing regions. They chemically analyzed acids and compounds in the hops and convened a trained sensory panel to analyze the hop aromas. These two methods revealed significant between-state and within-state differences for both varieties.
The research proved that Cascade hops grown in Oregon were characterized by strong citrus, floral, fruity, herbal, and resinous aroma. Cascade hops from Washington displayed more tropical and sweaty aroma.
Mosaic hops grown in Oregon were mostly characterized by strong citrus, floral, fruity and tropical aroma. Mosaic hops from Washington displayed stronger sweaty, vegetal, and woody aroma.
The researchers also brewed beers using 14 of the hop samples, the press release explained. Overall, most of the major aroma attributes identified in the hops also played an important role in the aroma of the beers. However, the importance of resinous, sweaty, and herbal attributes decreased from hops to beers, whereas citrus, tropical, fruity, and floral attributes were more important in the beers than they were in the hops.
What Does it Mean?
“These results will help hop growers in the Pacific Northwest of the United States as well as brewers utilizing hops from these major hop-growing regions to produce regionally unique beers or to blend hops in a way that results in standardized and constant beer quality,” Shellhammer said.
As far as consumers are concerned, you may start to notice more breweries discussing the origin of the hops in a particular beer. Instead of just mentioning Mosaic hops, you might see a label that says, “Brewed using Mosaic hops from Roy Farms in the Yakima Valley.” If you do, know that it’s real. There’s a reason they’re sharing that info.
Co-authors of the paper were Michael Féchir of Oregon State, Curtis Roy of Yakima Chief Hops, and Garrett Weaver of Coleman Agriculture. The research was supported by the Oregon Hop Commission, Washington Hop Commission, Oregon Hop Growers Association, and Washington Hop Growers Association.