Beer does expire at a certain point but when beer goes stale it does not mean it becomes unsafe to drink. You will probably get unpleasant tastes and aromas when you sip an expired beer. Even if you keep your bottle or cans in a cool, dark place, the conditions outside will still affect the flavor of your brew. Microbes and other natural factors can play a role, too. Your beer’s expiration date will tell you when it’s time to toss that bottle or can.
When you pop open a cold one this summer, you probably won’t even give it a second thought. But for those of us who are serious about craft beer, knowing when a bottle of something is no longer safe to drink is an important question to answer.
How to tell if the beer has gone bad
If your beer has gone bad, you’ll probably notice a few tell-tale signs. If you open up a bottle and the beer gushes out like it’s been shaken, this means that it’s off. It could also be off if the aroma is sour or tastes sour.
You might see white patches of yeast on the surface of the liquid, another sign that the beer has gone bad. The easiest way to tell if your beer has gone bad is by checking its expiration date.
1. Smell
Beer normally changes its smell when either it is exposed to UV light, gets oxygenated, or is infected by microorganisms. Stale beer will either smell like urine or be skunked depending on the cause of degradation. Sometimes, expired beer may taste like an apple or mowed grass– insinuating the presence of acetaldehyde in the beer.
Skunked beer is a result of regular exposure to UV light such as when beer is stored in direct sunlight for some time. Beer that smells like urine or cardboard when stale is caused by beer that has exceeded its shelf life markedly hence it is slightly oxidized.
If you smell a skunk-like odor, it means the beer has gone bad. The most common culprit of this is bacteria that have grown while the beer is in the bottle- leading to buttered popcorn or butterscotch smells due to diacetyl.
Give it a whiff and if you get a whiff of anything other than beer, then you know to toss it out.
2. Look
The first sign that your beer is going bad is when you see a dusty or cloudy layer at the bottom of the bottle. This indicates that yeast has formed and it’s breaking down the beer.
You may also notice changes in color, like turning from golden to brown. If you still think your beer tastes ok, though, you can always add a little more carbonation to freshen it up.
If you don’t drink your beer often and just have one or two bottles stored away for a rainy day, this might not be an issue for you. But if it’s been sitting around for months or years and it’s in a warm environment as well, there’s a good chance it’ll taste flat before you even open the bottle.
Another way to tell if your beer has gone bad is by checking the head on top of the liquid when pouring. If the head dissipates quickly and leaves behind only foam, that can mean it won’t taste very good either.
3. Taste
One of the reasons why beer goes stale is oxidation. Yes, we may want to eliminate as much oxygen as possible during bottling but it’s not possible to eliminate all. Oxygen changes the flavor of your beer.
This is because oxidation of the beer by oxygen produces different flavors such as a cardboard flavor). Other malty beers become sweet, grainy, caramel, and toffee notes.
The other thing to check for is if your beer has a “skunky-flavored” beer. The flavor is a result of exposure of beer to light.
It may have cardboard flavors or develop sweet, grainy, caramel, and toffee notes. If you find that your beer has a skunky flavor, then it’s time to throw it out.
4. Carbonation
Another sign that your beer is going bad or has already become stale is the lack of white foam rising right after opening a bottle. This should be the first sign of an old beer which indicates a lack of carbonation.
This can also be caused by over-chilling the beer. Beer should always be stored at refrigerator temperatures and never in the freezer because the extreme cold has been shown to inhibit the conversion of starch into sugar during fermentation, which results in less body and flavor.
