Whether you’ve just brewed a 5-gallon batch of homebrew or stocked up on some cases of your favorite commercial beer, you may be wondering how long you have before you have to drink the beer. Does beer spoil the way other perishables do?
All beer, whether in a can, bottle, or keg, will go bad eventually due to biochemical breakdown caused by oxygen, light, bacteria. Over time, beer will develop stale, skunky, and even sour flavors that will eventually make the beer undrinkable. Proper storage will greatly extend the shelf life of beer.
Read on to find out more about signs of spoiled beer, factors that cause it, and best practices for hanging on to beer for the long haul.
Does beer go bad?
Like all good things, beer doesn’t last forever. Its flavor and body will change over time, eventually becoming stale, skunky, or sour.
Though all beer eventually spoils, some evolution over time is desirable! Like wine, many styles of beer go through an aging and conditioning process that develops flavor and complexity.
Not all beers go through the aging process well, though.
In general, the higher the ABV, the better a beer will develop over time. This is because the additional alcohol prevents the development of bacteria or other undesirables. Styles like Barleywines and Imperial Stouts are designed to develop over time, meaning their flavors will become more cohesive even.
Despite their relatively high ABV, IPAs aren’t great choices to age in the cellar. They will lose their hop flavor and aroma over time and are usually best when consumed fresh.
Because of their high ABV and hop content, though, they are unlikely to be spoiled by undesirable bacteria.
Factors that contribute to beer spoilage and off flavors
After a while, all beer will spoil in one way or another. It may simply go stale or go so far as to be infected by the growth of bacteria.
Here are some of the key factors that contribute to beer spoilage:
- Oxygen – Beer must be stored unopened in its original can or bottle. Exposure to air causes oxidation, which causes stale, sour, or even papery flavors. Cans are naturally filled with a process that removes most oxygen from inside, but bottles have a bit of extra air in the neck of the bottle, which makes them more prone to spoilage.
- Light – UV light is the enemy of good beer. Light exposure through the walls of a clear, green, or even dark brown bottle causes skunky flavors and aromas in beer. Never store beer in direct sunlight or near a window.
- Container – When it comes to bottles, darker bottles are best because of the amount of light they block. Green or clear bottles are often used for beer styles where a small amount of skunkiness is desired. Cans block UV light but even they don’t last forever.
- Bacteria – Most homebrewers know that unwanted bacteria can be the death of a good batch of beer. If not stored properly, trace amounts of unwanted bacteria can take over in the bottle. Bacteria development is the most likely cause of issues for you if you drink it, but luckily this is usually pretty easy to spot as the flavor and aroma will become very different and usually unpleasant.
- Yeast – With bottle-conditioned beers, a mini fermentation is taking place inside the bottle. If fermentation gets too vigorous due to too many sugars present or storing the bottles at too warm a temperature, it can explode when you open it, becoming overly carbonated and likely producing off flavors.
- Temperature – It’s generally a good idea to store beer in the refrigerator, or at near-refrigerated temperatures. Most beer can be stored at room temperature, but it won’t last as long. Beer should never be stored in hot rooms or in the presence of direct sunlight, or in an area where temperatures don’t remain relatively consistent.
Can unopened beer go bad?
Most people know that beer doesn’t last long once it’s opening, but will not opening it ensure it stays fresh?
Beer should absolutely be stored unopened, but even unopened beer will get stale or skunky eventually. Once you open a beer, you expose it to oxygen, meaning you should drink it within a couple of hours for the best experience.
Read on to find out more about signals to watch out for and best practices for long-term storage.
How do you know if your beer is bad?
If you’re dusting off a forgotten bottle of beer from the back of your fridge or pantry, you may be looking for signs if it’s gone bad. Luckily, there are a few things to watch out for before you even taste it.
Here are a few warning signs your beer may have gone bad:
- Expiration Date – If your beer has passed its expiration date, proceed with caution.
- Leakage – Any signs of leaking beer mean the bottle or can has been compromised, exposing it to air. The remaining beer has almost certainly gone skunky.
- The hiss – If you don’t hear the hiss of air escaping when you open it, it may be flat.
- Head – Depending on the style, there should be an inch or so of head when you pour it into a glass.
- Aroma – A skunky smell is a warning sign that light exposure may have caused oxidation. For certain styles of beer, like Heiniken, a light skunky aroma is normal.
- Color – Expired beer sometimes turns a darker or even purplish color over time.
- Taste – When in doubt, taste it! If it tastes stale, sour, or otherwise unpleasant, pour it down the drain.
Can you drink expired beer?
Unlike many other perishable products, beer is still generally safe to drink after its expiration date. If beer is freshly expired, you likely won’t even notice a difference.
Beer that is many years old, however, has had its entire molecular structure changed over time, and should be avoided. Drinking beer this old can result in unpleasant issues like vomiting, nausea, and stomach problems.
Keep reading to find out how long your stored beer is likely to last before it’s undrinkable.
How long does beer last before it goes bad?
There are seemingly endless factors that will contribute to beer’s shelf life. Packaging style, beer style, processing method, temperature, and light exposure, to name a few, will all have an impact. An Imperial Stout, for example, will last longer than lagers or pilsners because of its additional alcohol content.
Given optimal storage conditions, here are some good rules of thumb for storing both commercial and homebrew beers:
|Unopened can||Commercial, pasteurized||6-8 months||1-2 years|
|Unopened brown bottle||Commercial, pasteurized||3-6 months||1 year|
|Unopened green bottle||Commercial, pasteurized||3-6 months||1 year|
|Unopened clear bottle||Commercial, pasteurized||3-6 months||1 year|
|Unopened can||Commercial, can-conditioned||4-6 months||6-8 months|
|Unopened brown bottle||Commercial, bottle-conditioned||3-6 months||6-8 months|
|Unopened green bottle||Commercial, bottle-conditioned||3-6 months||6-8 months|
|Unopened clear bottle||Commercial, bottle-conditioned||3-6 months||6-8 months|
|Unopened bottle (various)||Homebrewed, bottle-conditioned||6-8 months||1 year|
|Opened||Any||Two hours||24 hours|
Does beer last longer in a can or a bottle?
If you’re purchasing a beer specifically with the intention of allowing it to age, it’s important to choose the best style of packaging to ensure it lasts.
Due to the way it’s produced, bottled beer naturally has more oxygen in it than canned beer. Brown bottles also let a little bit of light in. Green or clear bottles let in even more. Since air leads to degradation, cans are the best bet for long-term beer storage.
Keep reading to find out how to maintain beer’s quality for the long haul by following a few simple steps.
How to properly store beer for maximum shelf life
If you plan to store beer long term, you’ll need to keep the beer’s temperature, storage vessel, and position consistent over time.
Follow these tips to maximize your beer’s shelf life:
- Refrigerate, but don’t freeze.
- Keep the beer out of the light.
- Store your beer upright.
Refrigerate your beer
A cool, consistent storage temperature is important for maximizing the quality of your stored beer.
Refrigerator temperatures are best for beer, especially when it’s being stored long term. If you have more beer than you have fridge space, choose a place like a basement that will be cool, but not frozen.
Be conscious of changing outdoor temperatures and how they affect your space. Also beware of sunlight pouring in through windows, even if it’s only for a few hours a day.
Finally, consider any temperature fluctuations in the space through the day or throughout the year. Choose a storage location with as consistent a temperature as possible.
Keep beer out of light
Light oxidizes beer, causing skunky flavors rather quickly so it is necessary to minimize exposure to light as much as possible.
Your best bet for long-term storage cans, but bottles can work too as long as they are in a dark place.
Cans block light entirely but even brown glass bottles let a bit in, so be sure to store them away from windows and sealed in a box.
Store your beer upright
Unlike wines and other alcohol, beer should be stored upright.
Storing beer upright minimizes the amount of surface area in contact with air, which, in turn, minimizes oxidization.
It also stores more easily and is less prone to rolling or shifting.