For beer lovers, fall is the magical time of year when the hop cone -- the flower on the Humulus lupulus, aka the magical hop plant -- is ready to be harvested. Something like 99% of beer is made with the dried form of hops. But when the cool weather starts to blow in, fresh green hops offer brewers the chance to put out regional beers that are rare and delicate: fresh-hop beers.
Fresh-hop beers were born in the Pacific Northwest, where Oregon and Washington, along with Idaho, farms produce about 98% of America's hops. During the annual hop harvest, most of the haul is dried out in a process that concentrates their bitterness, making them more shelf-stable for the rest of the year.
In the early '90s, brewers in the region started experimenting with the freshly cut, undried hop cones. They're used within 24 hours of picking, which imparts a fresher floral, green, grassy, and oily flavor and aroma. Due to the quick pick-and-brew nature of the beers, fresh-hop beers are rarely produced outside of the Cascadia region.
In addition to the fleeting harvest, beers made with fresh hops decline in quality much more rapidly than regular ones, so the hunt is on for connoisseurs during this season, with fans stalking Twitter and Facebook for tapping info and release dates.