Arkansas hops researchers seek maximum yield and cone quality

JOHN LOVETT

CLARKSVILLE, ARKANSAS

 The Arkansas Agricultural Experiment Station and microbrewery partners across the state are exploring Southern-grown hops and their unique characteristics for beer brewing.

The experiment station, the research arm of the University of Arkansas System Division of Agriculture, is fine-tuning research on growing hops in Arkansas through an Arkansas Department of Agriculture Specialty Crop Block Grant.

“We are refining cultural management practices for hops production in Arkansas to target maximizing yield,” said Amanda McWhirt, associate professor and extension horticulture specialist for the Division of Agriculture.

McWhirt has been growing hops at the Fruit Research Station in Clarksville since 2019. She’s now testing hop cone quality and yield with varying numbers of hop bines per plant. A bine is like a vine but grows in a circular, upward pattern and attaches via small hairs on the plant, whereas a vine attaches itself to objects via tendrils. The research will be key to maximizing the productivity and competitiveness of Arkansas-grown hops, McWhirt said.

Make room for Southern-grown hops

Liz Preston of Prestonrose Farm and Brewing Company in Paris is one of the state’s brewers who has worked with McWhirt on the hops project.

“The most important thing we’ve seen so far in this project and growing hops at this latitude is for brewers and consumers alike to adjust their performance expectations in hops produced here,” Preston said.

Hops are typically grown in Northern latitudes, which receive more daylight in the growing season. Hops grown in those regions typically have higher levels of alpha acids that impart bitterness, McWhirt noted. Preston explained that Southern-grown hops have lower levels of alpha acids, allowing the fruity and floral aromas and flavors in hops to come to the forefront.

“It is a classic example of terroir, and I think Southern hops deserve a spot in the huge spectrum of hop variety and characteristics in the brewing world,” Preston said.

Terroir, in this context, refers to the impact of soil, geography and culture or farming choices, on the hops’ flavor and aroma profile.

With less bitterness and more fruitiness, Southern-grown hops are ideal for dry hopping and producing non-alcoholic beers. “Dry hopping” refers to adding hops to beer during fermentation or after fermentation in a keg.

 The flavor compounds like hop acids and polyphenols that drive hop bitterness and flavor stability in beer depend on the variety being grown, said Scott Lafontaine, assistant professor of flavor chemistry for the Division of Agriculture. Research has also shown that hop flavor attributes areimpacted by the regionandfarmwhere they are grown, Lafontaine said.

Lafontaine plans to investigate how the concentrations of hop acids and polyphenols in nonalcoholic beer and hop waters influence human health and food choices that people make.

Preston said hop water drinks like hoppy kombucha are growing in popularity, and she looks forward to seeing those kinds of products being produced in Arkansas.

Preston has grown hops at Prestonrose, a certified organic farm, for several years and offered input from her experiences to McWhirt. Preston is brewing a beer with hops grown at the Fruit Research Station, which will be offered in a yet-to-be-scheduled public release event.

McWhirt and her hops project team partnered with Ivory Bill Brewing Company in Siloam Springs last fall to release a beer made with Arkansas-grown hops. In February 2022, Stone’s Throw Brewing in Little Rock held a public releaseof a beer dry hopped with hops grown at the Fruit Research Station.

The two-year Arkansas Department of Agriculture Specialty Crop Block Grant supports the current hops research through September 2024. The $76,762 grant is federal funding from the U.S. Department of Agriculture and administered through the Arkansas Department of Agriculture.

“The Department of Agriculture is pleased to help administer the Specialty Crop Block Grant funds that provide assistance to this important sector of Arkansas’s agriculture industry,” said Arkansas Secretary of Agriculture Wes Ward. “We are excited to see innovative specialty crop research funded by the Specialty Crop Block Grant, like the Arkansas grown hops study, that provides economic benefit to producers and our rural communities.”

Current research

After documenting which hops grow best in Arkansas, McWhirt is now determining maximum yield per linear row foot and increasing yield through new methods of arranging the hop bines to grow in a desired way. Testing will include how manipulating the number of bines per plant impacts yield and hop cone quality in Arkansas. The research will be key to maximize the productivity and competitiveness of Arkansas-grown hops, McWhirt said.

Renee Threlfall, food science research scientist with the experiment station, is collaborating with McWhirt on the hop cone quality study. Aaron Cato, a researcher and extension specialist in integrated pest management in horticulture, is working with McWhirt on pest management practices in hops.

A previous three-year research and evaluation project, also supported by a Specialty Crop Block Grant, was completed in 2021 at the Fruit Research Station to determine which hop varieties grew best in Arkansas. The study showed that Cascade and Zeus hops had the best yields, plant health and vigor while Crystal and Cashmere showed moderate potential for being grown in Arkansas. ∆

JOHN LOVETT: University of Arkansas