Just like glassware, and serving temperature, beer has an implicit (sometimes explicit) “best by” serving date. But beer is a funky thing—there can be wiggle room. Say you don’t want to (or aren’t able to) serve your beer immediately. How long can you keep it? And when, if ever, should you intentionally age it?
As it turns out, with beer, fresh is generally better. Most beers are brewed to be consumed fairly quickly (as in soon after they’re brewed, not “chugged”). And that’s because the volatile compounds that make up beer’s flavor will change, and often deplete, over time, while the proteins that give it body will deteriorate, and oxidization will slowly take hold. There’s also the possibility that beer in glass bottles (especially green or clear) could be skunked by exposure to light (it doesn’t take much). Hop-forward beers especially are best consumed early, as the volatile hop aroma compounds will be most available sooner after brewing.
But there is absolutely room in the beer world for aging. In fact, all beer can be “aged” (or really, stored) for a few months (longer when kept in the right conditions). But some beer can be aged for, well, ages—from many months to many years. Aging beer is always a slight gamble, a calculated risk that the structure and character of the beer will not only stand up to the test of time, but actually improve. And as with wine, there are a few factors that make a beer more appropriate for aging.
Alcohol by volume, or ABV, is one of them. A stronger beer, that’s at least 7 to 9% or above, has a better shot at maintaining some of its character (if not developing more) as it ages (higher alcohol beers tend to have more complex flavors, if only because high alcohol requires more fermentation, not to mention would be also registered as imbalanced in the final brew without other flavors). And wild beers, or beers fermented with not only traditional yeast but certain microbes associated with wild beer styles (lactobacillus, pediococcus, brettanomyces) have a better shot of improving—or evolving—with age.
So what happens when a beer ages? Many things. When a beer ages successfully, yeasts still present can continue to change the character of the beer, certain flavors may dissipate, bringing other flavors center stage, and even certain positive aspects of oxidization may occur.
As for the “right conditions” in which to store and/or age your beer, two elements are essential: dark and (moderate) cold. Beers like to age in creepy places: dank basements, dark garages, anywhere it’s generally cool (55F is a good rule of thumb) and free of sunlight. Remember, the UV rays in sunlight can skunk your beer—or impart off-flavors—and while green and clear glass are the most susceptible, an amber glass bottle left in even a bit of sunlight over time has a good chance of being skunked. So anytime you’re going to put a beer aside for a period of weeks, months, or even years, make sure there aren’t any sneaky rays of sunlight creeping around. Also essential is aging and storing beers upright, as is consistency of temperature.
And obviously make sure you’re not storing your beer near a heat source. As tempting as it may be, don’t display your beer collection over the family hearth.