On beer

Even though I'm a cork dork, I do enjoy a good beer every now and again (in fact, the Fiancee gave me a basic homebrewing kit for Christmas this year, and the bottles of my first batch are carbonating even as I type), which got me to thinking, how do different beers vary?

Beer is really just a combination of about 4 items -- starch/sugar, yeast, water, and hops. Of those 4, even though the water is what breweries harp on, the water is the least important (think about it; with a good water purification filter, basically all water is the same). The yeast determines what kind of beer you'll be making (ale or lager). The general source of starch/sugar is malted grain, and different grains will yield different flavor characters to the beer. Hops impart the bitterness and flavor to the beer.

So what is an ale? How does it differ from a lager? Basically, the difference lies in where the yeast ferments in the mix and the temperature that the yeast enjoys -- ale yeast (Saccharomyces cerevisiae) ferments on the top and ferments best near room temperature, while lager yeast (Saccharomyces uvarum) ferments on the bottom and prefers cooler temperatures. On a technical level, lager yeast eats more sugar, which results in a crisper beer, but ale yeast results in a bit more robust beer.

Then what about the hops? Generally, hops add bitterness. A little hops = a little bitterness, a lot of hops = a lot of bitterness. There are also flavor characteristics added by hops -- floral, citrus, or herbal notes. Hops also act as a preservative, favoring the brewer's yeast over all the other stuff that can grow in beer. Different strains of hops (eg, Cascade, Hallertau, or Willamette, among others) will add different flavors or different levels of bitterness. Some beers will note how much of an influence the hops have had by listing their bitterness level, as mesured in IBU's (International Bitterness Units, and yes, there is a formula and standard for measurement) -- more IBU's means bitterer beer. As a rough scale, Bud Light rates about 5 IBU's, Guinness about 45, and Dogfish Head 60 Minute IPA is about 60 IBU's.

Now, different styles of beer have different characteristics. For example, an India Pale Ale, or IPA, tends to be a very highly hopped light ale (it's named for the extreme use of hops in ale made by British brewers for their troops in India -- the beer wouldn't survive the long voyage without it). Stout is a type of ale that is made using roasted malt, resulting in a characteristic dark color and often a cocoa/coffee note. Pilsener refers to a pale, hopped lager made popular in the Czech town of Pilsen.

One of the joys of beer is that it's more like cooking than wine is -- with wine, if you have the same ingredients (grapes grown in the same spot, the same strains of yeast, same kinds of barrels), in different years the wine may still indicate different characteristics. Not so much with beer; it's more akin to making a recipe. You do the same thing consistently and cleanly, and the result is the same.

Which means, of course, that it's a perfect beverage to mass-market, as it's the same if it's brewed in San Francisco as it is if it's brewed in Vienna. It's also relatively easy to scale production; a brewmaster can make a small batch of a beer as a sample to see if large-scale production would make sense.

Photo from Clemensfranz, on Wikipedia.