Does Beer Last Longer In Cans Or Bottles?
We don't usually think of alcohol as something that "goes bad," and in many cases it doesn't. Lots of liquors can last indefinitely, so long as it's stored properly: in a cool, dry place in a sealed container, etc. Beer is a little more complicated because it doesn't expire in the same way another drink might, but it can certainly go stale over long periods (we'll get into that in a bit).
This leads to the question of how you should be properly storing your beer. If you forget about some bottles or cans of beer in your fridge, how long are they good for? While both beer cans and beer bottles will last several months in the fridge (sometimes up to two years) before they begin to lose flavor, aluminum cans usually win over glass bottles when it comes to preserving freshness. This is partly because cans protect the beer from direct sunlight better than semi-transparent bottles, and partly because cans are often sealed better than those long necks.
Keep the elements out
If beer is left in the sun for too long, it can become skunky, which simply means the flavor and smell of it has degraded and turned sour. Buying beer in cans helps because sunlight can't pass through the solid aluminum. It can however pass through glass bottles and will begin to chemically alter the brew. Darker-colored brown, green, or blue bottles can offer slightly better protection than clear ones, like Corona when sitting out open on picnic tables, but still less than a can does.
Oxygen can also spoil beer, leading to a flat or bland flavor. It's impossible to completely can or bottle beer without any oxygen slipping in, so the beer always goes stale eventually. But over long periods, the seal around the bottle cap can start to degrade. It's not enough to make the cap fall off, but it'll start letting in oxygen and this can build up.
Keep it cool
It's important to note that there isn't much difference in the average shelf life of a can versus a bottle. The printed "best before" date on any beer represents how long the manufacturer can guarantee quality, but beer cans and bottles commonly taste fine for six to nine months past that date in the pantry, and up to two years past that in the fridge. The ideal fridge temperature is about 37 degrees Fahrenheit, although beer can safely be refrigerated at temperatures up to 50 degrees Fahrenheit — just keep bottles away from sunlight.
A beer's alcohol content plays a much bigger role in how quickly it drops in quality, because heavier beers with more alcohol often last longer. And remember, once any container of beer has been opened, it'll go bad quickly because of all the oxygen. Leftover beer can be a great ingredient in whatever you're baking, like bread or cake; otherwise, anything leftover should go down the drain, not back into the fridge.