INDEPENDENCE, Ore. — Around the world, vintners already know how a region's climate, soils and farming practices — collectively known as "terroir" — can influence the character of winegrapes.
But what about beer? Are the same factors responsible for driving subtle yet distinctive changes in hops?
Coleman Agriculture, one of the largest growers of hops in Oregon, is working with researchers at Oregon State University to find out. The company began measuring terroir at three of its hop farms last year in the Mid-Willamette Valley, and testing whether there is a relationship to flavor and aroma in the crop.
"Our initial answer is yes, there is," said David Henze, president of Coleman Agriculture, which hosted a panel discussion and field event Aug. 9 at the Alluvial Farm near Independence, Ore.
Panelists included project leaders with Coleman Agriculture, as well as OSU faculty members Tom Shellhammer, Betsy Verhoeven and Shaun Townsend, and Andy Gallagher, a soil scientist and consultant based in Corvallis.
Liz Coleman, one of six owners at Coleman Agriculture, recalled the "aha!" moment that led to the hop terroir study. It was after touring the Trisaetum Winery last summer in Newberg, Ore., and hearing about how terroir impacts winegrapes that Coleman drew a correlation to hops.
She reached out to Shellhammer, Nor'Wester professor of fermentation science at OSU, to ask about what was being done in the field of research. As it turns out, there wasn't a whole lot.
That's when Coleman said she had a vision. Coleman Agriculture farms more than 8,000 acres, including roughly 2,200 acres of hops, from Independence north to Mt. Angel and the home farm in St. Paul, about 40 miles away.
"Because we have three distinct regions, we had the opportunity to do this on our farm," Coleman said. "It's been some time since we've had something in this industry to rally around."
Coleman assembled what she called the "dream team" to participate in the study. Gallagher, who owns Red Hill Soils, mapped soil profiles at each farm, noting differences between newer alluvial sediments and basalt rock that washed into Oregon 15,000 years ago during the Missoula Floods.
"Within the region, we have different soils dependent mainly on parent material," Gallagher explained to more than 100 people who gathered for the field day.
Verhoeven, who works with OSU Extension in Marion and Clackamas counties, said they identified 120 variables in terroir that could have an impact on hops. The list was whittled down to 50 main variables, related mostly to soil and climate data.
Finally, Shellhammer brewed three single-hop beers sourced from each of Coleman Agriculture's three farms. Tests showed differences in the beers, though more work is needed to determine what variable is responsible for what changes.
"People are seeing differences," Shellhammer said. "It just naturally begs the question, why?"
The implication, however, is that hops are not simply a commodity crop. Even within a single variety, there may be subtleties and nuance based on terroir.
"It can follow a similar path as winegrapes," Shellhammer said.
If that is the case, it could have an effect on farming, breeding and marketing of hops in the future. Garrett Weaver, terroir program manager for Coleman Agriculture, said the information could help farmers know what they need to do to grow hops with certain qualities for craft brewers.
The U.S. craft beer industry grew 7% in retail sales in 2018, up to $27.6 billion, according to the Brewers Association trade group. Craft beer now accounts for nearly one-quarter of the $114.2 billion total U.S. beer market.
Michelle Palacios, with the Oregon Hop Commission, said U.S.-grown hops are typically marketed broadly, though terroir could be a new philosophy to start recognizing differences between regions.
"It has been casually mentioned over the years," Palacios said.
Townsend, an aroma hop breeder at OSU, said studies like these are important for both the art and science of hops and beer.
"This is just the beginning," Townsend said. "We're just scratching the surface of this."