Nobody wants to eat expired food. Mold and bacteria growing on rotten food can cause serious health problems. But how about beverages? Do they go bad? More specifically, what about beer? Does beer expire?

According to the Best Practices Guide to Quality Craft Beer guide created by the Brewer's Association, "most beer is at it's best before it leaves the brewery." I.e. the fresher the beer, the better. But that doesn't necessarily mean that the beer you buy at the grocery store is bad. Though it does mean that beer does have a finite shelf life in terms of flavor and aroma. So, the short answer is that, "yes, beer does expire." IPA's, for example, are only good for about 30 days, lagers tend to last a fair bit longer, and some beer styles, such as imperial stouts, are good for a year or more.

How Long Does Beer Last

How long beer lasts depends on a lot of things, including the type of beer in question and how it was manufactured and packaged. Though, perhaps the most significant variable in the shelf life of beer is how it's stored. Here is a chart illustrating the amount of time it takes for beer to spoil relative to how it is stored:

As you can see, the colder the storage temperature, the longer the beer lasts. Beer stored at room temperature or outside in an unconditioned garage the gets warmer than room temperature will make beer go bad faster. That's why we always recommend buying beer from the refrigerated section of your local bottle shop or grocery store. Beer sitting on pallets or displays at room temperature in the middle of the store is sure to be less fresh than the beer in a cooler.

Does Some Beer Last Longer?

An example of beer that lasts a lot longer than others is beer that has been brewed with sour bacteria. This type of beer typically takes many months just to mature and be ready for bottling. Then, once it's packaged it typically lasts quite a long time.

For example, we once let a can of sour pumpkin beer sit in our refrigerator 5 years! Imagine you left milk in a refrigerator that long. We aren't scientists but there is a chance that it'd be deadly.

We're home brewers, which means that we make beer at home. And boy do we. In most years we brew more than 100 gallons. That's 177 six packs of beer! We drink most of it, but we tend to make so much that every now and again a stray beer, or sometimes even an entire keg, get forgotten about. 

Drinking Expired Beer

Defying all logic, we actually drank the the pumpkin beer that we accidentally stored for nearly half a decade. How did it taste? Well, it was absolutely delightful when it was fresh. It tasted like fresh pumpkin pie with a hint of sour from the lactobacillius bacteria we added. Unsurprisingly the 5 year old version of the beer wasn't great. But it also wasn't horrible. Actually, it wasn't even bad!

Whereas the fresh version of our sour pumpkin ale tasted like fresh pumpkin pie, the aged version tasted like a somewhat stale gingersnap cookie. It would have been much better if drank when it was fresh. But it was an interesting experiment nonetheless.

Can beer sit so long that it becomes poisonous? According to Craig Thomas from the Firestone Walker Brewery, “Pathogens cannot live in beer, so from a health standpoint, beer cannot go bad.” So, while there is an optimal window in which to drink beer, odds are that if you drink expired beer, you're going to be just fine.