Does Bottled Beer Expire?

Today, our beer experts discuss the question: does bottled beer expire?

Have you ever been digging in your fridge, and you find a bottle of beer that you’re not sure how long it’s been sitting there and if it’s OK to drink?

Most of the time, we just pour out bottles of beer that in our mind are “too old” to drink. But that feels pretty wasteful, and so we’re left asking the question: does bottled beer expire? 

We often ask this question about commercially produced beers that get lost in our beverage fridge, but it’s more relevant with a home brew. 

Bottled beer does have a shelf life and will eventually expire. And the shelf life of your home brew is even shorter because your production standards are different from those used in commercial brewing operations.

Will Bottled Beer Expire?

Does bottled beer expire?
A lot of Iron Drink Cans Lids

This is kind of a “glass half full” sort of question. In a way, yes beer does expire, but also in a way it doesn’t. Certainly, that doesn’t clear things up, and in fact it may create even more questions. Let’s try and clear the water on this quandary.

Most beers have a shelf-life. In most cases, if your beer remains in a cool, dark spot with a stable temperature, bottled beers have a solid shelf life of about 6-months. If you consider the question simply from a time perspective then yes, your beer does have an expiration date, or to be more exact, a “best by” date, and that is usually 6-months after it has been bottled.

However, just because you’ve hit or exceeded the 6-month mark doesn’t mean that the beer in the bottle is bad or “expired” like you think of with foods like milk. The beer in the bottle may be just fine, and thanks to the brewing process and typical beer ingredients, the beer that is past its best by date, is still safe to drink, but it may not taste the same.

Over time, beers will oxidize, thanks to a small amount of air left inside the bottle. Oxidized beers won’t taste the same as their fresher counterparts, but the beer isn’t bad. Also, thanks to the pasteurization process that occurs during the boiling stage of making wort and the antibacterial properties of hops, old beer shouldn’t have unsafe organisms, it just won’t taste right. 

How to Tell if Bottled Beer is Bad

We’ve all heard or told the tales of drinking a bottle of beer that was “skunked”. Skunked beer is the tell-tale sign that your beer has gone bad. The cause of the funky flavor has a few sources, but if your beer smells or tastes wrong (and by wrong we mean foul, not just a beer style you don’t like) then chances are it’s gone bad. If you’re desperate and drink it, it most likely won’t hurt you, but you may never want to drink beer again, and that would be a sad outcome.

There are four ways that your beer can go bad: Oxygen, Light, Heat, and Bacteria

1. Your Beer Has Been Oxidized

Beer that has oxidized has a strange buttery flavor. This is most often the way that commercial beers go bad. It’s nearly impossible to bottle beer without any oxygen. Many bottlers will top their beers with CO2 or Nitrogen to push out any remaining oxygen, but this isn’t a perfect process, and a tiny bit of oxygen will always remain. This little bit of oxygen is what causes most commercial beers to go bad. And, since you likely don’t have the ability to add nitrogen on top of your beer before bottling your homebrew, this is the number one way homebrew beer goes bad.

2. Clear Glass Bottles Ruined Your Beer  

Ever wonder why most beers are in amber bottles or cans? Well, it’s to protect your beer from light. UV light can create a chemical reaction with some of the compounds left in your beer from hops. This chemical reaction is the source of the “skunky” odor present in many beers that go bad, particularly those stored in clear glass bottles. Green bottles are better, but not as good as amber glass bottles.

3. Your Beer Got Too Warm

Heat and light kind of go together. They cause a similar chemical reaction to hop compounds resulting in that unique and awful “skunky” odor. The best way to avoid changes in the chemical composition of your beer is to keep it in a cool, dark place (like your fridge) where the temperature remains consistent.

4. Poor Cleaning Practices Can Ruin Your Beer

This is a greater problem for homebrewers than commercially produced beers. Bacteria can foul your beer at any stage after the boil. This is especially true if you aren’t doing a good job of cleaning and properly sterilizing your bottles and equipment. Once alcohol has been produced, it takes a while for bacteria to actually become a problem in beer, but it can happen, resulting in a terrible odor and smell in your homebrew. 

But What About Cellared Beers?

Cellared beers have become popular in recent years, and they are the exception to the rule when it comes to beer shelf life. Many commercial brewers are intentionally developing beers that are intended to be put away and cellared like wine. 

These beers are generally high in alcohol content or are heavy with hops. Depending on storage conditions, they can have shelf lives of a year or more. Like wines, these beers develop and change in their flavor profiles over time, and they are intended to go through this process.

However, this doesn’t mean that high alcohol or high hop beers will last forever. Most people who cellar beers usually don’t hold them for more than five years. Longer than this, even beers made to last will start to get funky and lose their desired taste profiles.

So, when it comes to beer, and expiration dates, a good rule of thumb is to drink most beers when they’re fresh. That will give you the flavor experience that the brewer wants you to enjoy. Some beers are made to last longer, but these are unique and should be cared for like wine. Our advice? Don’t overfill your beer fridge. Buy what you can drink (and do so responsibly) while the beer is fresh. That way you never have to risk getting a mouthful of skunky beer.