December 2, 2011

Beer, Aging and Why It Doesn't Survive Like Wine

Aging beer is a subject of contention for some, especially when it comes to homebrew. Certainly those big commercial beers can improve after a year or two of aging, but most people agree there's a point where beer ages in a bad way and goes bland or over-oxidizes. It's one of the reasons why beer is distinguished from wine, which can be aged sometimes for centuries. Wines get more valuable with age and are considered superior beverages, at least in part, due to their ability to improve with age.

This ignores some of the realities between wine and beer. Wine, at least modern wine, is assisted with additions of chemicals that improve stability by killing off bacteria and yeast. We don't often make those additions to beer. Additionally, wine yeast are badasses, some produce a compound that kills other yeast so the chance of wild yeast infecting the beer goes down. One substantial difference is that wine is low is extremely low in proteins, which are a major part of the breakdown in the quality of beer over time. Additionally, the higher alcohol percentage tends to prevent any bacteria or wild yeast from surviving in the harsher conditions.

Commercial beers tend to have the yeast and much of the protein removed from the beer (you need some to produce head retention) to assist in quality control and stability over time. Some even do have head stabilizers and other chemicals added to clarify and stabilize the beer. Although this helps stabilize the beer, even beer under pressure in bottles will experience some destabilization as the proteins break down into less enjoyable flavors. Like wine, those beers corked will have micro-oxygenation and develop a changing flavor over time. For beer, that combination of protein destabilization and oxygenation often results in bland flavor over the long term rather than the development of interesting, sherry flavors in wine.

Beer is best stabilized in cooler temperatures, even cooler temperatures than wine. For people who think wine is best aged, no matter what only need to stick a corked bottle in their garage or room temperature house for several years and give it a taste. Even wine stored in the 70s or above will destabilize at those temperatures. Beer, again due to the proteins, but also hop compounds, needs even colder temperatures to prevent destabilization. If one wants to age beer, room temperature is fine to produce beneficial flavor compounds from aging but typically after 2-3 years the process reverses and starts to produce bland beer. (Sours, which are dryer and already have some of the proteins broken down and consumed are more stable and can survive longer.)

Homebrew is even less stable since we tend not to add stabilizers, filter, or cold store our beers. Instead we are at risk of the same destabilization along with autolysis, increased protein destabilization (often because we have more remaining in our beers) and warmer conditioning temperatures that accelerate destabilization. Nevertheless, we often find ourselves wanting to make those big beers and then age them. Bigger beers tend to survive the aging process better because the alcohol wards off the effects of random bacteria and wild yeast in our beer and they hold up against destabilization better. In fact, they often improve from aging. In writing this, I am currently enjoying a delicious BGSA that is about 18 months old. It has definitely mellowed and improved with time. But it's 10% ABV. There will come a time when that beer has aged too much. The best thing you can do for your beer is age it a sufficient amount of time (which depends on the style and ABV) and then let it remain cool at refrigeration temperatures to inhibit further aging. That can be difficult when you have limited refrigerator space and/or no cool basement.

It's my experience that beers in the 5% range reach the limit of beneficiary aging around 9 months. After that they begin a slow decline into bland. That doesn't mean the beers go bad you just might notice the flavor changes for the worse and over time it becomes less enjoyable. But you could enjoy that beer right into a couple of years of age. It seems to me each percent of alcohol above that adds another 3-4 months. Obviously cool aging will delay aging and slow the destabilization. Anyway, that's just my experience.

More interesting posts coming after finals!

1 comment:

  1. This is great, thanks. Did not know some of this. I'm aging some meads in corked bottles without much temperature control and it's food for thought. Like your blog BTW.

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