Humulus Lupulus = Hops.
They aren’t involved in the fermentation of beer. They aren’t even a major component. You might have 6 kg of malt in a homebrew batch but only 30 g hops. They don’t get roasted. And they occur in virtually every commercial beer.
Hops are preservatives, they have sedative properties and give bitterness and certain flavour characteristics to beer — even Budweiser.
Many substances have been used to flavour beer — bog myrtle, spruce tips, rosemary, etc. Several hundreds of years ago, brewers used a mix of herbs called gruit.
Gruit consisted of such botanicals as yarrow, mugwort and heather to flavour and preserve the beer. It probably also hid the off-flavours resulting from medieval brewing practices.
Gradually hops became the dominant herb in beer.
The writing of Pliny the Elder in the first century A.D. contains one of the first known references to hops. Russian River Brewing makes a mean imperial IPA in his honour; a just memorial for a man who succumbed to the noxious gases of Mount Vesuvius while attempting a rescue mission.
By the eighth century A.D. hop vines were being cultivated in Europe. Europeans ensured that hops were spread throughout the globe, bringing them to North America in the mid-1600s.
The number one hop producing country (also the number two beer-drinking country per capita) is Germany. United States is second and China is third.
Europe used to look down its nose at the fledgling United States on the hop front. The U.S. brewing tradition developed its own peculiarities. Their original hops were stronger, with a coarse flavour and aroma. But now the Yakima Valley of Washington and the Willamette Valley of Oregon are important hop-growing regions of the world.
A classic American-style beer is the Sierra Nevada Pale Ale. The flavour and aroma is from a U.S.-bred hop called Cascade — a staple in many American microbreweries.
Cascade hops are citrusy (think grapefruit) and piney. The release of Cascade hops in the 1970s proved that Americans could cultivate decent varieties of hops and create new beer styles for a growing population of beer aficionados.
The American homebrewing revolution in the 1970s pushed beer into a new frontier. The revolution included the corruption of traditional English styles and the heavy-handed use of American-bred hops.
The in-your-face, resiny hop bombs known as American IPAs take a while to get used to, but they are a happy sign of a nation blowing in the face of tradition — the sort of behaviour we expect from the United States.
In the beer world it’s a good thing.