Even when I was a just a lad discovering the wonders of inebriation (“Dude, like, my tongue is numb!”), I was already aware that some beers had more cache than others. Everyone knew imported beer was way better than the American stuff and was a sign of class (I learned this from advertising), so I graduated to Molson, Moosehead, Heineken and St. Pauli Girl. You just knew from the pretty lady on the St. Pauli Girl label that this was a good beer.
Turns out that like many beer drinkers, I came to associate the sour, skunky, wet paper taste of these beers with quality. What I didn’t know was that imported beer in green bottles is most likely to suffer from the three main enemies of beer freshness — time, heat and light. Imports typically spend months in the cargo hold of container ships, in tractor-trailer trucks, and in warehouses before arriving at your local retailer. Temperatures in transit can easily reach over 100 degrees. During that time, the beers can suffer from oxidation, chemical reactions from the compounds in the beer that result in paper-y, metallic or buttery flavors that are generally not desirable. Heat and motion accelerate oxidation, making imports particularly susceptible. Time also results in a gradual breakdown of the hop character in beer, which gives it a dull flavor and a lack of head retention.
Beer in clear or green bottles is most likely to be “light-struck,” as well. This results when UV rays break down compounds from the hops, which then bind with sulfur from amino acids in the beer to create a “skunky” taste. Recent research has shown that the chemical compound produced, prenythiol, is the same one found in skunk spray, so the notion of “skunked” beer is not a spurious comparison. Beers can become light-struck even after a few days under the fluorescent lights of a beer cooler. Incidentally, Miller Brewing has solved this problem in their Genuine Draft beer by chemically altering the hops rather than using more expensive brown bottles.
The problem with spoiled beer is not restricted to imports, either. As the variety of beers available has increased, many American-brewed craft beers are allowed to sit on the shelf far too long. Liquor stores often do not properly store or rotate their stock. In my constant efforts to stay informed about the best beers available, I go through quite a lot of beers, and believe me, I have suffered through many skunked, oxidized and stale beers. I recently had a Left Hand Ginger Juju that I discovered too late was over a year past its “best by” date and was not refrigerated as recommended on the label. This is unfair to the brewery as well as the consumer, since many unsuspecting beer explorers may venture to try something new and decide they don’t like that brand or style of beer.
To avoid getting spoiled beer, check for a “brewed on” or “best by” date stamp, and avoid those that are not so labeled, especially if they have a fine layer of dust on them or visible sediment in the bottle (bottle-conditioned beers, however, are supposed to have a yeast sediment). Most pale ales, lagers and hefewiezens are best within three to six months of brewing. Darker beers and those with higher alcohol content might last a year. A few special beers are meant to be aged, but they are the exception rather than the rule. Beers stored in the cooler are less likely to spoil than those stored at room temperature, although many liquor stores stack case boxes on the floor, and those beers are less likely to be light-struck.
Some breweries will by back beer that is past its freshness date (Sam Adams is well-known for this), while some will split the cost with the distributor. In other cases, the retailer is left holding the bag for beer that did not move well. Still, liquor stores should not sell beer that has lost its quality. Let retailers know that a beer is expired or to return beers that you find to be stale (don’t do this just because you don’t like the beer — read some reviews of the beer and see what it is supposed to taste like). Check back in a few days and see how they have responded to your complaints. If the expired beer is still on the shelf, let them know that you plan to shop elsewhere.