On sprawling farms clustered around Wilder and Greenleaf, thousands of green Humulus lupulus vines snake vigorously skyward. A relative of marijuana, these hop plants produce resiny, cone-shaped flowers prized for their use as a bittering agent in beer.
Idaho is the nation's third largest hop producer behind Washington and Oregon, representing about 15 percent of the national market, according to the Idaho Hop Commission. The majority of the state's approximately 3,000 hop acres--which include varieties like Cascade, Chinook and Centennial--are in Southern Idaho, while the rest hover up north near Bonners Ferry.
On a recent Saturday, a bus packed with Boise brewers and hop heads motored out to Wilder to two large hop farms: Gooding Farms and Jackson Hop Farm.
"There's a huge disconnect between the people who are producing hops--which is what craft beer is currently crazy about--and the craft beer lovers. The hops that they want so much are just 45 minutes away," said David Roberts, beverage director at Bittercreek Ale House. "Just seeing the reactions of people on the bus as they for the first time saw these big, beautiful hop farms. ... There are mountains of these hops and the aroma is overpowering."
That afternoon, Bier:Thirty owner Chris Oates used hops plucked fresh from the vine to flavor a keg of Payette Brewing Co.'s North Fork Lager, which tour-goers tipped back while listening to live music by Hillfolk Noir.
"They literally just went and picked the hops off the vine and we filled them up inside of this filter and we ran a keg through it," explained Oates.
Brewers from Kilted Dragon also gathered about 10 pounds of fresh hops and carted them back to Boise to brew two beers: Bonnie Heather, an amber with heather tips, and the seasonal Kilted Pale Ale.
"Those two beers were ones that we were producing anyways, so it was a good opportunity for us to not only experiment but also add that local flair of the hops themselves," said Kilted Dragon co-owner Jeremy Canning. "Up until now, we don't usually get hops locally because they're just not as plentiful or available to small guys like us."
Most of Idaho's 4 million-pound, $11.3 million hop crop is dried and shipped to large commercial breweries that have long-standing contracts with local farmers. But during the fall harvest, local craft brewers can get their hands on a limited amount of fresh hops, which need to be used within a day to preserve their flavors.
"Most hops that are used in beer, and this is part of why fresh-hop season is so cool, have been processed in a plant where they're ground up and then packed together," said Roberts. "A result of all that friction is heat. And at a certain temperature, the active ingredient in hops--the lupulin, the pollen ... that gives the flavor and bitterness to beer--will begin to degrade."
Due to these processing factors, dry-hopped beers have a different taste than wet-hopped brews.
"A dried hop is more concentrated in flavor whereas a fresh hop to me is more floral," said Oates. "It depends on the hop that you're using, but with the fresh hop, green pastures is what always comes to me."
In addition to those aromas, Roberts said fresh hop beers, because of essential oils, have a unique mouth-feel.
"[I]f you use them fresh, you have that maximum amount of organic oils ... and I think they translate in the finished product into this really resinous, oily, coating mouth-feel," said Roberts.
Because wet-hopped beers can only be brewed and consumed during a short window in early fall, their release has become cause for celebration across the Northwest. In late September and early October, towns like Yakima, Wash., Portland, Ore., and Hood River, Ore., all host fresh-hop festivals.
In that spirit, Oates and Roberts have organized Hop Moon, an inaugural Idaho fresh-hop celebration Saturday, Sept. 21, during which more than a dozen fresh-hop beers will be released simultaneously at Bittercreek Ale House, Bar Gernika, Whole Foods River Room and Bier:Thirty. The event, which organizers plan to repeat yearly, will also act as a kickoff for Boise Beer Week, which runs Saturday, Sept. 21-Saturday, Sept 28.
"We see the hop harvest, and the embracing of it in craft beer culture, as kind of a counterpoint to Oktoberfest," said Roberts. "In the recent past, there's been giant attempts at Oktoberfest celebrations ... and while I don't think there's anything wrong with that, and I do like light German lagers, I think that a more appropriate celebration of beer at this time of year where we live is fresh-hopped beers."