As a brewer I have been asked many times: does beer go bad? As you can see by the length of this post the answer to this question is not a straight yes or no. The short of it is that yes beer does go bad. But that statement can be misleading because as you will see it does not mean beer expires. There is a significant difference between going bad and expiring.
Very much like wine or spirits, beer ages with time. The difference is that a well-aged wine or whiskey is a delicacy and something to be enjoyed, not so much with beer. As beer gets older its flavor, aroma, and appearance all continue to evolve and change but after a certain point, this evolution starts to break the beer down instead of improving it.
The flavors and aroma imparted by the hops are the first to go, they fade very quickly. Off flavors are developed due to exposure to oxygen which interacts with its ingredients in a negative way. The mouthfeel or body of the beer becomes very thin as the proteins start to disintegrate and break down. A vinegar sour-like taste starts to develop and the carbonation leaves the beer resulting in it becoming flat.
But as alluded to this does not mean that it has expired, as it is still safe to drink, it has just become very unappealing and not something most people would want to consume…
Does Beer Expire? 
When people think of a food source expiring I would wager that milk is one of the first things that comes to mind for most. Beer does not expire in the same fashion as other food sources like milk. It does not become unsafe to consume. Its taste will become very unpleasant but it will not expire to the point that you can not drink it if you really wanted to.
Why is it that beer expires but does not go bad per se?
When a beer is brewed the process it goes through actually kills off any of the harmful bacteria or organisms, if brewed correctly these unwanted guests simply can not survive in the beer’s environment.
There are 3 main reasons for this:
- Beer has a low pH which inhibits the growth of bacteria.
- The alcohol content and the obvious effects it has on the beer.
- The hops in the beer are actually a preservative and provide an antibiotic-like effect that prevents contamination and significantly increases its shelf life.
Then why does it go bad?
You would think that the combination of alcohol, low pH, and preservative qualities of the hops would keep the beer from going bad indefinitely. The problem is not when the beer is brewed but rather when it is packaged.
Regardless of what a beer is packaged in, whether cans, bottles, kegs, or growlers there are two substances that go into the packaging: the beer itself and oxygen.
Oxygen is the culprit for the breakdown of the beer. It is pretty much near impossible to package a beer regardless of the method without a little bit of oxygen getting in. When beer is fermented under pressure may be the only exception to this rule. Over time this oxygen causes all of the negative changes to the beer. We call this oxidation.
How Long Does Beer Last?
The majority of beers taste better fresh. If you have ever had a beer served fresh at a taproom versus the same beer purchased from the beer store you understand this very well. There is a significant difference in the taste, mouthfeel, and aroma of a beer freshly brewed. This holds especially true for your favorite hoppy beers. There is no comparison between a freshly brewed IPA and one that you purchase in a can 2 months after it was brewed.
Having said that there are exceptions to the rule and some beers actually do taste better with a bit of age. Many English ales when given the opportunity to condition improve with time as do imperial beers, sours, and barley wines.
However, the majority of beers will maintain most of their freshness for approximately 6 – 9 months stored at room temperature and up to 2 years at refrigerator temperatures.
Depending on how the beer is packaged also plays a major part in how long a beer will last…
How a Beer is Packaged Affects its Shelf Life
Bottles & Cans – Beer packaged in a can or a bottle will have similar shelf lives, which is between 6 – 9 months stored at room temperature and up to 2 years at refrigerator temperatures. The one thing to watch for with bottles is the shelf life can decrease if it is exposed to sunlight, this is especially true for green and clear beer bottles. Exposure to sunlight can create a skunky off-flavor which we will discuss in more detail further in this post.
Growlers – These are a great way to be able to bring some beer home from your favorite craft brewery, however, do not plan on storing it long, as beer does not last very long in a growler.
You have about 3 days maximum before it begins to break down. Growlers are not airtight like bottles and cans, they allow more oxygen to get in, which combined with the UV effects degrades the beer much quicker than other packaging methods.
Crowlers – If you want to store beer from your local craft brewery, longer crowlers are a better option. As long as you store them correctly the beer will remain fresher for a longer period of time due to how they are filled and the fact they are made out of aluminum and not glass.
Kegs – Beer stored in kegs will last the longest due to how they are packaged and the ability to be able to purge the majority of the oxygen from them. Beer stored in kegs is said by some to be able to last indefinitely, although I would not go that far, I would concur that if packaged correctly you can store them for several months to a couple of years without any concerns of the beer going bad.
How to Tell if Beer is Bad
If it is a commercial beer you have purchased from a beer store the simplest way to tell if a beer is bad is to simply look at the best before date on the side of the packaging. However just because a beer may be past this date doesn’t mean it has gone bad. Before simply throwing it in the trash pour yourself a glass of it to confirm.
First, take a look at it and see if there are any floaties or clumps floating in it. Next, take a look at the color, has it changed in color from what it should look like. Paler-colored beer styles will actually darken up quite a bit and some beers can even take on a purple color when they have gone bad. Next, take a smell of the beer, does it have any funny odors you would not typically expect to find in a beer; a smell of vinegar is a sure sign that the beer has gone bad.
If it looks fine and smells ok it is time for a taste test. Once again the first obvious sign will be if it tastes like vinegar. If it does, it has been contaminated by wild bacteria or yeast. If the beer tastes flat this means that the packaging has a bad seal and the CO2 has escaped and Oxygen has been allowed to penetrate it.
If it passes all of the above tests your beer is fine regardless of how old it is.
One thing to point out is when you are performing the smell or taste test you notice the beer has a skunk-like smell it does not necessarily mean that the beer has gone bad, it is most likely as a result of a completely different reaction within the beer occurring…
How Does Beer Get Skunked?
Believe it or not, some brewers will intentionally package their beer in the green or clear bottles in order to give the beer that slight skunked taste and smell.
Some people are under the false impression that heat causes the skunk-like characteristic, this is not the case. What makes this occur is a chemical reaction between the iso-alpha acids from the hops in the beer and sunlight.
When beer is exposed to sunlight these acids are broken down and create a new chemical that is very similar to the one created by skunks, hence the odor and taste of a skunked beer.
Can You Drink Expired Beer?
Drinking an expired beer is fine and will not hurt you as long as the packaging has not been compromised. If the packaging has been dented, punctured, cracked, or has lost its seal there is a chance that the beer has been compromised and should not be consumed as bacteria could have infected it.
If you open the beer and it does not make the hissing sound we have all come to love, that means the carbonation is gone as a result of the CO2 being able to escape which means the packaging has been compromised so it is not worth taking the chance of drinking it as it could make you ill.
Frequently Asked Questions
What to do with expired beer?
Surprisingly there are all sorts of things that you can do with expired beer. I have seen people use it as a:
- Rust remover for screws, bolts, and old tools
- Fertilizer to help grow grass
- Healthy hair shampoo filled with vitamin B
- Wood furniture polish
- Carpet stain remover
- And even a bug repellent
The following is a post with a video and overview of 4 of the more popular things you can do with expired beer.
Can you freeze beer?
The short answer is yes you can freeze beer but you should not. If you like a really cold beer or just purchased a warm one and want to get it chilled down quickly it is ok to put your beer in the freezer for 20 – 30 minutes but you should not allow it to freeze for two reasons:
The first is that you will end up with a beer slushy. Due to the alcohol content, the beer is going to turn slush-like.
The second is that like all liquids it is going to expand when you freeze it. As it expands the extra pressure is going to cause the packaging (can, bottle, growler, crowler) to either break or lose its seal.
I hope this cleared up some of the misconceptions about bad and expired beer for you. Long story short beer is best served fresh, but as long as it has not spoiled drinking expired beer is so much better than wasting this delicious beverage we all love and enjoy!
Cheers, Big Robb is Out!
