Higher alcohol can be a factor and I have heard Jamil Zainasheff who does a show on beer styles on the Brewing Network has a theory. He said that he thinks the darker and roasted malts in beers like winter warmers can add a presevative power into the beer. He didn't cite any studies on the episode, but noted it doesn't work for Pilsners or the like they die as beers after 6 months. However even a brown ale with a bit of chocolate malt can be aged out to some extent.

I usually buy a case of Sam Adam's Octoberfest beer every fall and drink one bottle at a time as a treat to myself through January. One year, I let a bottle or two go to March and I gotta say, it definitely did not taste anywhere near as good as it had the previous September. Needless to say, I now make sure it's all gone by the end of January, as Sam Adams recommends.

Dogfish head actually recommends that you age their 120 Minute IPA in a cellar or other cool, dark place. You don't have to, but they say it makes it even better.

I've never tried it (if I spend 10 bucks on a single bottle of beer I'm gonna drink it soon), but it would seem to support the high-gravity preservation argument.

Of course, that's such an extreme case who knows if it applies to any other beer.

As a general rule higher ABV beers age better than lower, low hop beers age better than high hop beers, and dark beers age better than lighter beers. Consequently the best candidates for aging are high malt, low hop, darker styles - such as English style barley wines, Imperial stouts (low hop types) and a number of Belgian styles. just to suggest a few - there are others.

Hugh

Clipper City's Below Decks is an awesome beer as is, but put a few in the closet or your basement for a year and they become super awesome!

Ahhh, Sammy Adam's Octoberfest is another seasonal that I wish was available yearround! Like Bruce, I try to stock up at the end of each fall, but unlike Bruce, my supply is usually gone by Christmas!

I personally do not know all the specifics on aging beer. I have always been told to drink a beer within 3 months of bottling for the best results. Anything more than 6 months was pushing the limits to it's "quality".

However, I do have a bottle of BFM Abbaye de Saint Bon-Chien 2006. I bought this in January at State Line Liquors in Elkton ( I will drive to find good beer as I live near Annapolis). This is a Sour Ale from Switerland with 11% APV. It is in a 750 ml bottle. They also had some from 2005 as well. The year is printed on the bottle. However, I have been told that this beer can be aged up to 2 or 3 years. Generally, it is prefered to age at least a year before consuming. I have yet to open it and try it, waiting for a day with friends to do a tasting. But I do know that they did have several bottles at State Line.

Barleywine styles definitely improve with age.

I have a few 4-packs of 2006 Clipper City Below Decks that is unbelievably good right now.

I also have a couple 4-packs of the '07 that I'm holding off until September to try.

I agree with Hugh--who would want to disagree? In fact, it is the main reason I can enjoy a nice barleywine out of season, or waaaay out of year, with my stilton regardless of the weather.