This is a guest post by Jeff Alworth, writer, blogger and Portland beer enthusiast.
Beer is a liquid in flux. The four (or sometimes more) ingredients combine to make scores of flavor and aroma compounds in a beer, and they are constantly interacting with one another. Just after beer’s birth, when a few yeast cells are still floating around and munching the last tasty molecules of sugar, those compounds need a bit of time to ripen before the beer is perfect. Unfortunately, they don’t stop. In sciencey terms, this is because, to turn to Belgian researcher Bart Vanderhaegen’s dense academicese, “the constituents of freshly bottled beer are not in chemical equilibrium; … thermodynamically, a bottle of beer is a closed system and will thus strive to reach a status of minimal energy and maximal entropy.” In other words, beer is unstable, and it will begin changing the minute it’s bottled.
Within days and certainly weeks, the lively molecules of flavor that animate fresh beer start interacting with oxygen and the clean lines collapse. The process is something like stewing—the flavors blend together and become dull and muddy. That’s why breweries spend zillions of dollars to try to deliver beer to customers’ hands as soon as possible and why, in almost every case, it’s best to drink beer as soon as possible.
But not every case: there are a few important exceptions in which beers need extra time to ripen in the bottle—imperial stout, doppelbock, barley wines, and old ales. The tradition of aging these beers is centuries old, though, and aged stouts and barley wines were rare birds indeed—squirreled away in the cellars of a few connoisseurs. With the rise of craft brewing, though, the number of beers that require aging have multiplied. Most breweries release at least one of these types of beers—they don’t all have recognizable style names anymore—and they are often greeted with anticipation by fans who buy each year’s “vintage.” These beers are usually strong and dark, often flavored with chocolate, coffee, spices, or other unexpected ingredients. In a trend less than a decade old, breweries regularly maintain large barrel rooms filled with cast-off whiskey and wine casks so they can infuse their seasonal specialties with the hints of pinot or bourbon.
For the beers that compose this special category, the rules are turned on their head. When they’re released, these beers send up plumes of alcohol as strong as wasabi and have chalky bitter bodies or lacerating hoppy finishes. Those same chemical processes that ruin standard beer help tame these strong, green beers over the course of months or years of cellaring. These beers need time to come into focus, and once they do, one is startled by how smooth and elegant they become.
For the beers that take to aging, time becomes one of the ingredients. (Some breweries, like Bend’s Deschutes, even have a “best after” date—usually a year after release.) When the flavor elements come into harmony, a cellared beer is unlike anything else in the world. They’re not pub beers; rather, they’re more akin to a cordial of brandy or two fingers of Islay malt. These are the most rare of beers, the kind you reserve for special occasions. Yet for as little as ten dollars a bottle, you can start stocking a cellar that will reward you, just a year or two down the line, with something sumptuous and decadent.
In the following short series of posts, we’ll explain which beers to age (and which not to age); what happens when a beer is aging; how long to age a beer; and aging beer made with wild yeast.