Steve Luke, the head brewer and founder of Cloudburst Brewing, was halfway through a day of brewing when he handed me a small glass of A$ap Hoppy, an IPA conditioned with wet, uncured Centennial hops. I took a sip and it popped with leafiness, like sucking on a freshly picked herb. Fruit flavors then started to dominate, with notes of pineapple and tropical fruit, before the beer delivered a classic bitter IPA finish.

I told all of this to Luke, and he turned and walked back behind the bar and poured himself a small glass, took a sip, and seemed surprised by the beer's finish, "I didn't remember it being this bitter yesterday," he told me.

Professional brewers hardly ever want to be surprised by their beer—consistent flavor is a trademark of a good brewery. But A$ap Hoppy is no normal beer: It's a wet hop beer, which means that instead of curing the hops (the flower that gives beer its aroma and flavor) first, they go directly from the hop farm to the brewing kettle. By skipping the curing process, wet hop beers are dynamic and volatile. They burst with fresh and unusual flavors for a couple of months in the fall and then fade almost immediately.

Luke wasn't fazed by this. He seemed delighted that his beer changed after just one day. "I'm curious how it will taste tomorrow," he said with a smile.

These extraordinary beers are almost exclusively brewed and served in the Pacific Northwest. It's a big deal: If Seattle were a European city, we would close schools, call a bank holiday, and shut down traffic to celebrate wet hop beers. The mayor would ceremoniously tap the first keg, and we would flood Instagram with photos bragging about these special beers.

But that doesn't mean Washington brewers invented the style. Ancient brewers probably threw a few uncured hops into some boiling wort a thousand years ago, but Washington's Yakima Valley hops are central to this modern beer style. Famed British beer writer Michael Jackson documented an English brewer using uncured hops in 1993, and wrote that he was aware of only one other brewery using uncured hops. While he doesn't provide a name, Jackson does refers to it as a brewery "in the far West of the United States." That brewery might be Bert Grant's Yakima Brewing, founded in 1982 and widely considered the first American brewpub since Prohibition. Located in downtown Yakima until closing in 2004, it was in the heart of hop country, and Grant would take advantage of the local harvest by experimenting with uncured hops.

We're also not the only place today with access to wet hop beers. Brewers around the country can now get uncured hops shipped overnight, and some big breweries widely distribute wet hop beers. But still, the Pacific Northwest explores this style more than anywhere else, and Portland and Seattle are the best places in the world to drink wet hop beers.

We owe these special beers—and almost all American beer—to the Yakima Valley, where, just a three-hour drive east across the Cascade Mountains, hundreds of people are harvesting hops seven days a week. About 75 percent of the beer made in the United States is made with Yakima Valley hops. The vast majority of these hops will be heated in kilns, where their green cones will lose most of their moisture on their way to becoming a shelf-stable product. But a tiny minority will go straight from the hop vine to a waiting pickup truck, where it will be driven to breweries across the Northwest, like Cloudburst Brewing.

Just five hours before Steve Luke handed me a glass of A$ap Hoppy at Cloudburst, Chad Roberts, a brewer with Yakima's Varietal Brewing Company, filled up his Subaru Baja with more than 300 pounds of freshly picked hops and headed for Seattle. Roberts brought two varieties of hops to Cloudburst: Cascade, probably the most famous aroma hop in the world, and a new experimental varietal called HBC 438. As I watched, he split open an HBC 438 hop and held it close to his nose.

"It's really unusual," he said. "I get lime and a creamy coconut aroma."

This is part of the allure of wet hop season. It's a time of experimentation, when brewers are finding new aromas in classic hops like Cascade and figuring out how to use brand-new varietals like HBC 438. In Seattle, we get to be the beta testers of these experiments, and this year's fresh hop season might have next year's trendiest hop flavors. HBC 438 might even be the world's next it hop: California's Russian River, one of the trendiest breweries in the world, has started playing with it, and Lagunitas Brewing chose to showcase HBC 438, often referred to as "Ron Mexico," for the first beer brewed in its new Seattle brewpub.

Luke and Roberts started dumping the bags of both HBC 438 and Cascade into Cloudburst's mash tun, filling the stainless-steel container almost to its brim with about 350 pounds of uncured hops. That works out to about 35 pounds per barrel of beer (for comparison, Cloudburst uses about four pounds of cured hops per barrel for standard IPAs). Hops spilled out of the mash tun as more and more bags were dumped in. At one point, Charlie Papazian, the author of The Complete Joy of Home Brewing and widely recognized as one of the godfathers of American craft beer, walked into the brewery and laughed when he saw the mash tun filled to its brim with hops.

Luke started transferring hot wort—the sweet liquid base of beer—into the mash tun, mixing it with the fresh hops. A$ap Hoppy had only whispers of wet hop flavor, but this new beer, which Luke calls "Wet Bandits," should be dominated by them.

Wet Bandits will be released in late September and, like all wet hop beers, its flavors will warp within hours of being kegged. After a month, it will barely resemble the original beer.

"It's this race to get it inside of you and enjoy it right now, because the stars are already fading once it's in the keg," Luke said.

As we finished up our glasses of A$ap Hoppy, I asked Luke how he thinks the beer will taste in two months. Without skipping a beat, he replied, "Like shit."

Drink these beers now, Seattle. They're worth it. recommended