Driving through Oregon's lush Willamette Valley at the peak of summer, it's hard to not notice the walls of green marching across the horizon, looming over narrow country roads as you approach their ranks. Seeing those lovely giants thick with fresh cones, it's hard to believe hops weren't always grown in the Pacific Northwest. After all - Washington, Oregon, and Idaho have dominated the American commercial hop market for over 100 years. But much like many of our traditions, hop cultivation has historic European roots.
Hops grow wild in North America, Europe, and Asia, and the first recorded mention of the plant - to some debate - is from Pliny the Eldar's Naturalis Historia written between 77-79 AD. In his book of botanical observations, Pliny refers to wild hops as lupus salictarius (charmingly translated to "willow wolf"), an Italian food novelty. It's not until seven centuries later when hops are first connected to brewing. Abbot Adalhard of the Benedictine monastery of Corbie (in what is now Picardy, Northern France) wrote a series of rules in 822 AD on how the Abbey should be run. He included a description on gathering wild hops for beer, although it's not clear whether they were used as a preservative or for flavoring. Regardless, this document shows wild hops were at the very least being collected for brewing use.
Historians don't know exactly when the first commercial hop farms began popping up, but it was most likely in Northern Germany between 1100 and 1200 AD, when breweries of the Hansa trading towns were exporting hopped beer to surrounding areas. The Low Country's high society greatly enjoyed this German drink and, in turn, began to brew their own beer. By the 1360s, Dutch hop farms were supplying their local breweries, with Flanders to follow closely after. Hopped beer exports to England only continued this trend despite the initial push back from native drinkers of traditional unhopped ales. The first English hop farms were planted around the 1520s in Kent, then spread to other areas of the country as well as Scotland, with production peaking in 1878.
Throughout this evolution of commercial hop cultivation, the hops themselves were also undergoing a transformation. Wild hop varieties were consistently being discovered around Europe during the first few centuries of this craze, most likely still acting just as a preservative. In the late 1800s, brewers finally discovered it was the soft resin in hops - where alpha acids are produced - that decided how well the beer would keep, so growers started planting hops with higher alpha acid content to meet brewers' demands. Around this same time, American hop imports were on the rise, creating a very unique amalgamation of events. Tastes began to change from strongly-hopped beers to sweeter, more mild flavoring. Researchers at Wye College in Ashford near Kent began the first cross-breeding program in the early 20th century, blending the fruity, high alpha acid American varieties with floral English varieties. This created new and unique hop flavors with twice the preservative power, meaning less hops could be used in a brew to get the same amount of staying power. And the beers they produced were more mild - allowing the sweeter, more subtle flavors to shine. Many varieties grown today are based off these original crosses.
Small pockets of hop farms still exist throughout Europe, most in the historic growing areas of the past, like Kent and Northern Germany, but they're not as prevalent as in the past. Modern mechanization has all but wiped out small farms, and much of the momentum has swung America's way. Despite all of this, the Hallertau region in Germany continues to be the #1 producer of hops in the world, holding strong to their beer-loving roots.
So where does the U.S. fit into all of this? As you can guess from historic precedence, hops migrated with early European settlers to the New World and continued their march across the globe. You can read our story in next week's post. Stay tuned!
Hopservatory Manager, NASA JPL Solar System Ambassador