The four main ingredients in beer are malt, water, yeast, and hops. And though many people get excited about hoppy beers, many might not understand what exactly a hop is.
Hops are the flowers, or cones, of a plant called Humulus lupulus. Hops help to keep beer fresher, longer; help beer retain its head of foam—a key component of a beer’s aroma and flavor; and, of course, add “hoppy” aroma, flavor, and bitterness.
Hops belong to the Cannabinaceae family, which also happens to include Cannabis (hemp and marijuana). Hops are hardy plants and are grown the world over. Here in America, the largest hop producers can be found in Oregon’s Yakima valley. Though you’ll find hop producers across America, including up here in Maine.
A view of Aroostook Hops, a farm up in Westfield, Maine.
Every single beer on the market today contains hops. If they didn’t, they would be a “gruit” which is basically a beer that, instead of hops, uses witches-brew-sounding herbs like bog myrtle, yarrow, heather, or juniper.
Sidenote: bitterness can also come from fruits, herbs, and even vegetables added to the beer. For example: pith from orange zest, spruce tips, juniper, and more.
Hops are divided into two very general varieties: bittering and aroma. Bittering hops will have higher alpha acids, making them more economical for bittering beer (a small amount goes a long way). Aroma hops will tend to have more essential oils. It’s those highly volatile essential oils that contribute much of what people understand as “hoppiness.” We’re talking aromas like citrus, pine, mango, resin, melon, and more. By adding hops early in the brewing process, all of those essential oils volatize (boil away), either during the boil or during fermentation. That’s why adding them later in the brewing process tends to make a beer smell “hoppier.” Also, that volatility is the same reason why the aroma and flavor of heavily hopped beers don’t stand up as well to time. Much of the hop-forward aromas and flavors will dissipate, leaving quite a different beer than the brewer intended.
The use of hops varies greatly depending on the beer, and what the brewer is looking for. And it’s this variety of uses that makes hops such a delicious and versatile ingredient to brew with.