Chances are if you’re reading this, you have a beer cellar. Aging beer is all the rage right now as people are not only exposed to many more styles, but also as they learn exactly what their palates prefer. But, as eager cellarers start to wade in, it’s all too easy to fall into various traps. And one of the most common is “older is better.” It’s important to remember that eventually, all cellarable beers will succumb to the tide of time. Okay, an exception might be made for vintage greats such as Thomas Hardy’s and Cantillon, which have yet to hit the wall, but there’s nothing worse than drinking a beer that’s sat patiently for years, only to discover that it’s a shell of its former self.
It’s easy enough to recognize a beer that’s well past its prime with that first sip. Even non-beer drinkers can tell “old” when they taste it. However, having the ability to detect the indicative aged aspects before a beer heads downhill can pay dividends by enabling you to drink whatever stock you might have left in time and helping you learn where a beer’s peak is for the next time. Consider the following warning signs.
Thinning Body
One of the worst things that can happen to an aging beer is the thinning of its body. Over time, oxidation will reduce a beer’s sugars. As these sugars are oxidized, the by-products adhere to the malt proteins, eventually causing them to fall out of suspension, resulting in thinning. Many cellar-worthy styles (e.g., barleywines, imperial stouts) rely on a malty body to let their maturing flavors shine, and once this base is gone, the beer can become dull and muted.
Brett-Derived Medicinal Flavors
Many American breweries are just now jumping on the Brettanomyces bandwagon. Brett has wonderful advantages for cellaring: it is a fantastic oxygen scavenger (lowering oxidative effects) and creates a bevy of unique acids that over time can lead to the formation of the tropical fruit-like esters. However, Brett also has the ability to synthesize traditional Belgian yeast phenols (clove, pepper) into 4-ethyphenol (4-EP), a unique phenol responsible for both funky (horse sweat, barnyard) and plasticy/medicinal flavors. This synthesis can occur even in the Bretty-classic Orval, which begins to exhibit these characteristics after about three years. Once formed, these compounds are relatively stable so, if a young Brett beer acquires the dreaded medicinal flavor, it’s time to drink up or move on.
Stale Oxidation Flavor
Stale oxidation flavor is the biggie to look out for in your aging beer. While many of the great flavors (e.g., sherry, amaretto, dried fruits) found in vintage beer are due to oxidation, it’s also responsible for the dreaded “stale” flavor, often described as cardboard. And while you may not regularly eat cardboard, it’s easy to detect (just think stale bread). Most oxidative flavors are age-stable, so once they appear, they’re going to stick around. And sadly, once they’ve developed to a substantial degree, there’s no turning back.
Flatness
As a beer rests in the cellar, the bottle closure—be it cap, cork, or swing top—will very slowly leak minute amounts of carbonation. Given enough time, a beer will eventually become flat. Much of this comes down to the closure type (caps are generally the most secure, with corks close behind, and swing tops being a distant third), but it also depends on a brewery’s bottling practices. A cellar’s humidity can also speed this process if it’s low enough to dry out corks (below about 55 percent). Carbonation is a critical component to all beers, and once gone or significantly reduced, its absence can ruin an otherwise great beer.
Yeast Autolysis
Any beer that has been bottle-conditioned or not filtered prior to bottling will end up with some yeast in the bottle. Over time, a combination of alcohol, acidity, and temperature breaks down the yeast’s cell walls, a process called autolysis. Depending on conditions, this can take anywhere from one to twenty years, but the resulting yeast guts that spill into the beer create a variety of “meaty” flavors. In dark-roasted beers, the flavor is something akin to blood, while amber-colored barleywine-style ales suggest soy sauce. Conversely, light-colored beers such as saisons and lambics take on hints of roasted nuts. In tiny doses, these facets can add complexity to a vintage beer, but be on alert if they begin to appear so you don’t end up with an expensive bottle of teriyaki sauce.
Fading Beery Flavors
The quintessential flavors in a beer are those of malt and hops. A young beer should have these in spades, but the unavoidable consequences of an aging beer are when the maltiness slowly tightens and hoppiness (bitterness, aroma, taste) begins to fade. Many beers depend on these flavors to make them what they are, and once they are gone, the resulting beer becomes a boring one-trick pony. The hoppiness of American barleywines is a classic example, as many of them are essentially Double IPAs (DIPAs) with some caramel malt flavor. As the hoppiness starts to fade in these beers, it’s time to consider whether they have what it takes to make it much further.
Acetaldehyde Formation
Essentially, acetaldehyde is present in all beer, although usually at low enough levels not to be detectable. In higher amounts, a green apple flavor will emerge. Typically found in beers served too young (hence the name “green beer”), acetaldehyde is created during primary fermentation before being converted to alcohol during the conditioning phase. However, in an aging beer, the right combination of ingredients can sometimes lead to alcohol oxidizing back into acetaldehyde, a generally unpleasant circumstance. Even worse, in a “wild” beer with a variety of micro biota, this acetaldehyde can then be reduced into acetic acid (vinegar). Watch out for ‘dem green apples.
Again, it’s important to remember that cellared beers will age—gracefully for a while, perhaps, but less gracefully as time goes by. As Adam Avery suggests in “8 Tips for Successful Cellaring,” if you think a beer is good for cellaring, put away a case (or at least several bottles). Every once in a while, drink a bottle. If you detect any of the warning signs I’ve mentioned, it’s time to decide whether to drink up your stock or let it go a little longer.