Though it doesn't typically come with a "sell by" or expiration date, most beer should typically be consumed within a few months of packaging, if not sooner. Old, stale beer can possess off flavors such as skunkiness, wet cardboard, sherry/port, or even rotten veggies. Most beers are better fresh, which is why local beer often tastes so good - especially that at a brewpub. So why, then, is "aging" beer so popular? How can you know which beers age well and which ones will become undrinkably stale?
There are a couple of pretty reliable (though not guaranteed) guidelines - high alcohol content and high IBUs (lots of hops). Both help preserve beer (think IPAs) and can contribute to some pretty fantastic flavor changes over time. American Barleywines are great candidates for aging. It appears that smoked beers, which have seen a rise in popularity recently, are also great for aging since smoke has a preservative effect as well. I haven't tried an aged smoked beer, but is anyone else thinking "smoked barleywine"? Apparently I'm not the only one; the Dutch and Norwegians are one step ahead of me (every time I read something about Nøgne ø I tell myself I need to drink more of their beer. Really.)
I happened upon a fantastic resource about aging beer today that I plan on reading quite a bit in the future. The author covers topics ranging from how to store the bottles (right-side-up or upside-down?), proper cellaring temperatures and humidity, and the science behind aging. He's also published some great tips for cellaring beers (parts I and II.) The author also posts extensive reviews on beers he's aged, providing comments on 6-month and 12-month milestones. Really good stuff.
Even if you don't plan on aging your beer, here are some guidelines to keep in mind while buying beer. If there's a business in KC that does make efforts to properly store beer (UV-filtered lighting, quick shelf rotation, etc), please let me know. I'll be sure to mention them here - not to mention trade them my money for their beer.
Oh and speaking of beers suitable for aging, we were at Lukas in Martin City today and spotted Dieu Du Ciel's Imperial Coffee Stout, Peche Mortel. At $5.99 for a 12-oz bottle, it's a little expensive but well worth it. John and I went to their brewpub last summer and loved everything we tried (and, they had about 4 smoked beers there which was a welcome surprise). If you're ever in Montreal, they're worth a detour.
image credit to elliebrown.com