Within the community of beer-drinkers (and therefore, almost certainly, among the community of non beer-drinkers), there are an alarming number of people who are completely unclear about the role that hops play in beer. Many people believe they are what beer is fermented from (!), and many others don't know what they actually are. It is with this short article that I hope to answer some of these common questions.
What the Hell's a Hop?
Broadly speaking, hops are the flowers of the hop plant. It is in the same family as hemp, which has predictably led numerous resourceful idiots to try to smoke it. If you live in a hop producing part of the world, you can drive out to the fields and see this unique, vine-like plant soaring majestically into the air while you fantasize about all the great beers they will help to create. During the brewing process, hops are boiled, and their bittering alpha-acids extracted. There are also a variety of compounds that are found in the hops which add flavors and aromas, though these will dissipate if boiled for too long. For that reason, brewers will add hops in stages: bittering hops at the beginning of the boil, and aroma hops at the end. A brewer can also "dry-hop" a beer, which generally entails adding a fistful of hops to the secondary fermenter. These hops are then not boiled at all, and so contribute only aromatic and mild flavor qualities. Hops add no fermentable sugars - they are strictly a flavoring agent
Hop History
Hops, while a beer staple, didn't get their start until fairly recently in beer's history. Long used as a folk remedy for all manner of ailments, they are first documented as a flavoring agent in beer in 736 AD, but at the time, they were only one of many herbs, spices, and botanicals used to flavor beer, and were in the company of spruce tips (delicious), ginger, wormwood, and sage. Hop use became widespread in Germany by the middle 1500s, but they didn't become wildly popular in England and other areas until later yet.
Many find the bitterness that hops impart unpleasant; this bitterness is probably why so many people make a sour face when they have a sip of beer. It is an acquired taste, and the best way to develop a liking is to start with beers with very low hop bitterness: brown ales and doppelbocks, for example. Hops became popular, it seems, because their bitterness is perfectly suited to counteract the sweetness of the malted grains, so there is a good reason for their use - they really do help to create a perfectly balanced beer. There are dozens of varieties of hop, each with its own distinct flavor.
German Hops
There are four so-called "noble" hop varieties: Hallertauer, Saaz, Spalter, and Tettnanger. All German or Bohemian in origin, these hops are high in aroma and flavor but with a low alpha acid content, and are used predominantly in European-style lager. They generally have an herbal or spicy flavor, but (especially the case with Hallertauer) can have wide ranging tastes depending on where they were grown. Saaz and Spalt have more subtle, delicate flavors and aromas, which make them favorites in pilsners and other pale lagers.
British Hops
British hops are generally newer cultivars. Goldings was developed in the late 18th century, and is quite popular in English pale ale. They are earthy and herbal, with low-moderate bittering potential and a hay-like flavor. Fuggle is the other "main" British cultivar, and is lower in alpha acid content and has a woodier flavor and aroma than Goldings.
American Hops
Americans have been spearheading hop development lately, creating cultivars that are both delicious and uniquely American. A reflection of the people that created them, our hops are bigger, more assertive, and far more bitter than the namby-pamby, European varieties. These "Freedom Hops" (I think only I call them that) are generally hybrids between the classic European varieties described above and lesser-known types. American varieties are generally marked by strong citrus and floral characteristics, and many are fiercely bitter. Cascade might be the quintessential American pale ale hop, and if you drink American microbrews, you've almost certainly tasted it. It is actually relatively restrained as far as alpha-acid content goes, but its related cultivars, Centennial and Chinook, each contain more than enough to make up for it. These varieties will probably be the main bittering agent used in American IPAs. Willamette is another important American variety, originally bred from Fuggle, which replaces woodiness with citrus flavors.
There are a lot more varieties of hop than those that I've listed, but these will do to get you started as a hop connoisseur. The best way to get to know different hop flavors is to drink a lot of beer, paying attention to where the beer was brewed and what style it is (microbrewers will often list the hops used right on the box or bottle, as well). I'm sure you're up to the task.
