Just like life, the answer is complicated. There is no one size fits all solution. Many variables play a role in how long your keg will last; different styles of beer last longer than others, and how you tap your beer and the temperature at which your beer is stored greatly affects how long your keg will last.
Remember, it’s good to keep in mind that as soon as the keg is filled at the brewery is when it starts aging, not when you tap the beer.
Almost nothing makes your keg go stale quicker than using a manual pump/keg tap/party pump (the ones you see at house parties and backyard cookouts) to serve beer. These pumps introduce oxygen into your keg to pressurize it, which speeds up the beer aging process and causes it to go flat quickly.
With a manual pump, it takes about 8 hours before the beer starts to get stale and 24 hours before it’s completely stale. The more oxygen you pump into it, the quicker the beer will go flat. That’s why after enough use of the manual pump, your beer starts to have a much different taste than when you first started drinking it.
Unlike the manual pump, a kegerator or commercial draft system uses CO2 to dispense your beer. It avoids oxygen, which does a much better job at preventing oxidization and keeps your kegs fresher for much longer. Ideally, your keg will taste the same from start to finish.
With CO2 systems, your tapped keg can last anywhere from 3 months to 6 months – So much longer than a manual system!
Unpasteurized vs. Pasteurized
Whether the beer is pasteurized or not also affects how long your keg lasts. To tell if the beer is pasteurized, your safest option is to contact the distributor or brewery. Sometimes a simple search online can also provide you with the answers. If you can’t figure it out, error on the safe side and assume it is unpasteurized.
If you have pasteurized beer, it can last 3 to 6 months when stored at the proper temperature.
Unpasteurized beer has a much shorter shelf life, lasting about 45-60 days even when stored at correct temperatures.
No matter what kind of pump you use on your keg, you will notice a decrease in quality if you store it at the incorrect temperature.
Storing your beer at room temperature is never a good idea. Once the temperature of the beer rises above 50℉, bacteria start to form, and oxidization occurs and spoils the beer quickly. Besides, have you ever tried pouring a warm beer? Talk about foamy!
According to the Draught Beer Quality Manual, the general recommended temperature for storing draft beer is 38℉. Any lower than 28℉, the beer will start to freeze.
When beer gets too cold, it retains the carbonation too well and mutes the flavor and aroma of the beer. Frozen kegs could even (rarely) burst open due to the expansion of CO2.
It is recommended to keep your walk-in or wherever your will be storing your kegs as close to 38℉ as possible. It will guarantee your beer tastes fresh and lasts a long time.
Tips to Keep Your Beer Fresher, Longer
Buy a fresh keg
The number one tip is to buy it fresh! The first step to long-lasting beer is to buy a freshly made keg, not one that is nearing its sell-by date.
Don’t get it confused; the sell-by date isn’t the same as an expiration date. Your beer can still last months after the sell-by date with proper storage. You should not consume or sell beer to customers past the expiration date.
Store your keg correctly
In order for your keg to last a long time, you need to store it correctly. Choose somewhere cool and dark. Both heat and light damage the beer causing it to go bad quickly.
It is also essential to keep the proper pressure in your draft system. Too low of pressure results in excessively foamy and flat beer. Pressure that is too high shoots beer out of the keg rapidly, causing it to become foamy and spray everywhere, wasting your precious beer.
The recommended amount of pressure needed differs by the type of beer you use. As a general rule of thumb, you should keep the pressure between 10-12 PSI for most ales and lagers.
Know the alcohol levels of the beer
The higher the alcohol, the longer the beer will last. Bigger beers like barrel-aged stouts and porters are excellent examples of beers that last longer than average. Any hoppiness in the beer may fade a bit, but it will retain all other characteristics.
Order the right size of keg
If you are concerned about how quickly you or your business will go through a keg before it loses its freshness, you can buy a smaller-sized keg. There are many keg sizes and you can order a size according to the expected demand.
How to tell if a beer goes bad
Now that you know how long your keg should last, how do you tell if it’s gone bad?
- Foul taste: One of the most obvious signs of a bad keg. Your beer may taste unnaturally sweet or like sulfur.
- Cloudy appearance: Unless it’s a hazy beer, it should not be cloudy.
- Extra foamy: A little foam is normal, especially when using a manual pump… but a lot of foam- not so normal.
- Bad smell: Just like the taste, bad beer will taste either sickly sweet or sulfuric.
While drinking old beer doesn’t generally hurt you, it will not taste great, either, and won’t win you any favors in your establishment.
Now that you know how long a keg lasts and what a bad beer tastes like, it’s time to start thinking about your beer dispensing equipment.
Ranging from beer towers and coolers to drip trays and faucets, Liquid Cheers™ has a wide range of quality equipment for all of your draft beer needs. Visit our website or contact us today for more information!