As the new school year begins, I thought a quick primer on beer would be appropriate. First, beer is simultaneously “just beer” and anything but. By this I mean that beer is just a drink, but like most things, it’s more complicated than it appears at first. Webster’s dictionary defines beer as “an alcoholic beverage usually made from malted cereal grain, flavored with hops and brewed by slow fermentation,” which covers an awful lot of ground. So to begin with, the basic ingredients of beer are malt, hops, water and yeast. All styles of beer are made from recipes using different types and quantities of these same four ingredients, although occasionally other things are added as well.
The first thing you need to understand about beer is the fermentation process, as this leads to the classifications most people recognize. Fermentation is the process by which yeast consumes sugars and excretes alcohol, and variables such as the strain of yeast and the temperature play a huge role in the end product. There are three main classifications for beers based upon yeast: ales, lagers and spontaneously fermented beers.
Modern ale yeasts are quite adaptable, but the rule of thumb is that these yeasts ferment at higher temperatures, typically 60-70 degrees Fahrenheit, while lager yeasts ferment between 50 and 60 degrees Fahrenheit or even lower. The differences in temperature and yeast strain yield very different taste profiles, which can be overly generalized as follows: Lagers are clean, with the yeast contributing little flavor to the beer, and the fermentation is carried out near the bottom of the fermentation tank. In ales, on the other hand, the yeast hangs out near the top of the fermenter and tends to produce chemical compounds such as esters, which contribute to the flavor of the beer. Wheat beers form a special subset of ales that are traditionally left unfiltered; the yeast itself is consumed with the beer and contributes the bready character to these beers. Ale yeast can be fermented at lager temperatures and vice versa, which tend to blend these properties and result in hybrid beers such as the Kolsch and California Common styles.
The second ingredient is the grain used to make the beer. Malt is a term used for grain that has been allowed to germinate and is then dried out. This process allows the grain to produce enzymes that convert the starches to simple sugars during the mashing process. There are a huge number of different types of malt, as well as specialty grains that are roasted instead of malted, all of which contribute different flavors. One item of special note here is that the roasting of the grains is actually what controls the color of the beer; beers that contain a lot of roasted or kilned malt are darker (think Guinness) because the roasting process chars some of the sugars so that they cannot be fermented. One of the common myths is that all dark beers are thick and “heavy.” In fact, much of the mouthfeel of beers actually comes from proteins instead of charred sugars, which is why Guinness actually has such a thin mouthfeel while it is still quite dark (the creaminess comes in large part from the use of nitrogen instead of carbon dioxide as the compressed gas).
Malt can be made using virtually any grain, although barley is the most common. Wheat bears, obviously, contain a substantial amount of wheat malt (but generally not all wheat. Most homebrew recipes I’ve seen call for 50-60 percent wheat, with the balance barley), and rye is an increasingly popular grain due to the slightly spicy character it imparts. Other starch sources can be used, such as unmalted barley, wheat and rye; corn; refined sugars and rice. I’m a bit disparaging toward rice because it tends to contribute very little to the taste of the beer while increasing the alcohol content, yielding beers like Budweiser.
The third major ingredient is hops. Hops are actually the female flowers of humulus lupulus, and they impart both the bitter taste and much of the aroma to beer. The active ingredients are alpha acids, beta acids and various essential oils, all of which play different roles in the flavor. Alpha acids provide the bitter flavor, while beta acids provide the bitter smell. At least some hops are added near the beginning of the boiling of the wort (unfermented beer) so that the heat can isomerize the alpha acids. This increases the bitter taste of the beer, and most of the essential oils are driven off, leaving little or no aroma from this hop addition. Hops added near the end of the boil (or even after it is removed from the heat) add less bitterness and more aroma. Some beers, such as American India Pale Ales, will have hops added at several points throughout the boil to form a very complex hop character in the beer. There are many different types of hops, and just because you don’t like “hoppy beers”, doesn’t mean you won’t like any of them. The aroma can vary from woody and vegetative to piney or a distinctive citrus character, and many microbrewed American Pale Ales will utilize a late addition of a specific hop to make the beer interesting without adding much bitterness.
A very unique subset of beer is the sour beer family. These consist of beers that are spontaneously fermented, meaning that no yeast is intentionally added, and beer that is infected later in the process. These beer styles typically come from Belgium, where the fermenters were left uncovered so that the wind blew yeast and bacteria in, but they are now produced all over the world utilizing cultures taken from Belgian breweries. The yeast and bacteria produce lactic acid, which gives the sour taste, as well as alcohol and other byproducts that add a very complex character to the beer. These beers are quite strong and distinctive in taste, and they are frequently blended with fruit juice for general consumption. A common example of this is Lindemans Brewery’s blended lambics, which generally come off as a much tarter version of the fruit juice used to make them.
In conclusion, beer is a very complex drink that is influenced by each of its ingredients. Few hard-and-fast rules link different properties of beer together, allowing for a huge number of styles to be brewed by adjusting the types and quantities of the four basic ingredients. Not all light beers are thin, or dark beers thick, or hoppy beers bitter, or wheat beers extremely bready. So, the next time you are ordering a beer, think about trying something new, especially if you have never heard of the style before. You just might be surprised by a new flavor combination that you really like.