Most people aren’t the least bit self-conscious about squeezing tomatoes, thumping melons, sniffing ground beef, or reading the freshness date on bread wrappers at the supermarket. And don’t wine enthusiasts pay great attention to the harvest (vintage) year? Why, then, should beer drinkers be willing to dash into a store, grab any old six-pack off the shelf, and assume that the beer is fresh?
Don’t expect beer to be any more resistant to time, heat, and direct sunlight than other fresh foods. If your retailer stacks exposed six-packs in the front windows of the store where they’re allowed to sunbathe for several hours a day, file a report with the beer police at once! To summarize: time = bad, heat = bad, light = bad, refrigeration = good.
Younger beer is better
Three months is the average window of freshness (the shelf life) for pasteurized bottled or canned beer. Some beers have a longer shelf life than others. Fully pasteurized beers (heated for up to one hour, as are most megabrews) are more stable than flash-pasteurized beers (heated for only one minute, as are some craft brews). Also, hops and alcohol serve as natural preservatives, so well-hopped and stronger beers have a longer shelf life.
Heat can spoil a beer
Heat makes beer go stale really fast. Refrigeration is, therefore, the ideal way to extend the shelf life of beer. However, lack of proper refrigeration is a major problem for beer retailers and distributors.
Keeping beer out of the limelight
Any form of light is potentially harmful to beer. Light produces chemical reactions in the hop compounds. These reactions create a mild skunky (catty in the United Kingdom) odor. Incandescent lighting is bad enough, but fluorescent lighting — found in most stores — is even worse. (No, the light in your fridge isn’t going to destroy your brew.) Beer’s worst enemy is sunlight, however, because it’s both light and heat.
A beer that smells skunky is said to be lightstruck. Lightstruck beer is beer that’s been exposed to ultraviolet and visible light. One form of protection against light damage is colored glass. The more opaque the glass, the better: Green is good, but amber (brown) is best.
So why don’t certain beers in clear bottles, like Miller High Life, get skunky? It has to do with that particular brewery using a chemically altered hop extract that doesn’t contain isohumulones. No isohumulones, no reaction to light, no skunkiness!
Checking a beer for freshness in the store
How can you, the customer, know when a particular beer arrived in the store? Unfortunately, you can’t, but you can find clues in the beer or on the packaging that help you figure out which beers are fresh stock and which ones are on a long-term lease. Here are some general buying tips:
Whether you buy beer in cans or bottles, always reach for refrigerated stock first.
Check for a readable date stamp — if there is one.
When buying bottled beer, consider the color of the bottle.
Hold a bottle up to the light and assess the beer’s clarity. Except for beers purposely bottled in the unfiltered state, a fresh filtered beer should be crystal clear.
Give the bottle a gentle shake. Any little chunks of stuff swirling around are probably protein flakes that have settled out of the liquid — a definite sign that the beer is eligible for social security.
Check the airspace (the ullage) at the top of the bottle. The proper ullage should be no more than 1 inch from the top of the liquid to the cap. A larger-than-normal ullage may promote oxidation, especially with unrefrigerated beer. Don’t buy that bottle!