Since prohibition, American beer has been so traditionally homogenous that most Americans had only a vague awareness that there was an entire beer world outside of the standard rice and corn-based brews of companies like Annhauser-Busch, Miller, and Coors. Imports were really the only way to try unfamiliar ales or lagers, but they were often prohibitively expensive or had slogans too imposing for the average American beer-drinker (Tuborg Gold: The Golden Beer of Danish Kings!)
Since the mid 1990s, however, the American microbrew revolution has been in full swing, and you can find fantastic, American-made beers in any style you could choose, and many American breweries successfully compete with their European counterparts in international competitions. Beer is once again reasserting itself as a beverage that can be savored and appreciated rather than simply guzzled to enhance one's sexual appeal. To really understand beer, one has to understand the four basic ingredients that make beer.
Here comes the science:
What's in my Beer?
or, Fermented Grain Juice by Another Name
* Water - Water does much more for beer than make it liquid (though admittedly this is fairly important.) Minerals in the water used in beer making will give different flavors to the final product. The mineral content of the water from famous brewing cities is so integral to the flavor of certain styles that minerals must be added to brewing water in order to create authentic examples of the style. For example, the brewing water of Dublin is rich in calcium and sulfates, so when brewing an Irish Stout, gypsum (calcium sulfate) is added if the maker doesn't happen to have a large amount of Dublin water on hand.
* Grain - Malted grains provide the fermentable sugars that will be turned into alcohol, as well as the non-fermentables that will give "body" to a beer. Traditionally, this has been barley or wheat, but American and Asian beers often use rice or corn (which contribute a lot of fermentable sugars but not a lot of flavor), and oats are popular in certain styles (such as oatmeal stout). Any "malty" flavors in a beer will come from the grains, and certain grains can give beers their most distinct characteristics - for example, roasted barley in stout.
* Hops - Hops are the flowers of the hop plant, and contribute bitter or floral flavors and aromas in beer. The first use of hops in flavoring beer is documented as being in the 11th century, but they it didn't become widely known throughout Europe until the 16th (actually relatively recently in beer's long history). When a beer is described as being "hoppy," it generally refers to bitterness imparted by hops. Specific styles of beer are known for specific types of hops - for example, Czech Saaz hops are often associated with Pilsners, while Northern Brewer hops are a hallmark of California Common (Steam) beer.
* Yeast - Yeast are the magic fungus that turn sugar into alcohol, making possible the miracle of beer. There are two basic kinds of brewing yeast: ale and lager. Ale yeast is known as "top fermenting," because it ferments at room temperature and forms a foam at the top of the fermenting beer. Lager yeast is characterized as "bottom fermenting," because the beer is fermented at cold temperatures and the yeast tends to sink to the bottom of the fermenter. These two different yeasts provide the two basic styles of beer: ales and lagers. The fermentation process also produces esters and phenols, which provide for many of the fruity or spicy (respectively) flavors you might taste in a beer - especially a Belgian (note that beer can also have fruit added to it for an authentically fruity taste). Different yeasts will produce wildly different flavored beer, which is why breweries often guard their yeast strains carefully.
This should provide a basic understanding of beeriness. While other adjuncts (generally spices or fruits) can be added to beers, the beverage as we know it is really just these four simple ingredients. In subsequent articles, we'll look at the different styles of beer that have come out different regions, concentrating on the British Isles, Germany/Bohemia, Belgium, and the United States (which has, in fact, added more to beer than just watery, swill-flavored lager)
