How Long Does A Keg Stay Fresh?

Learn some best practices and guidelines for knowing how long your keg of beer can stay fresh.

You thought that keg of Baltic Porter was going to be a big hit, but now it’s a month later, and you still have a half-full keg sitting in your kegerator, and you can’t stomach another pint. Is that beer still good? How long before you need to wave the white flag and just surrender that beer? While we aren’t here to advocate wasting beer (gasp!), it is probably a good time to talk about how long a keg stays fresh.

How long does draft beer remain fresh?

There is no one hard and fast rule for how long a keg of draft beer will stay fresh. This is especially true for craft beers because different styles of beer last longer than others. A good rule of thumb is that the shelf life for a keg of pasteurized beer is about 90-120 days (or 3-4 months), and unpasteurized draft beer will last about 45-60 days (or 6-8 weeks) when stored at the proper temperature. Many imported and domestic beers are pasteurized. If you’re unsure whether or not your beer has been pasteurized, treat it like it is unpasteurized.

An important thing to remember is that countdown starts the day your keg is filled at the brewery, not when you tap it or buy it. One of the first things you should do when you pick up a keg is to check the label to see if it has a “born on” date or expiration date. If the beer in your keg is passed its expiration date, then we wouldn’t recommend drinking it.  

How long does a tapped keg last?

The method you choose for dispensing your beer also plays a major role in how long your keg stays fresh. Using a kegerator or draft system that dispenses draft beer using CO2 should not impact your beer’s freshness as long as the keg is stored at the proper temperature and pressure. You can follow the guidelines explained above to determine how long your tapped keg will last.

Using a picnic pump, party pump or keg tap is a completely different situation. These introduce oxygen into your keg, which greatly speeds up the process of beer going bad. Since a picnic pump uses oxygen instead of carbon dioxide, a tapped keg will only last about 12-24 hours, depending on the type of beer and how much oxygen was pumped into it. The oxygen will cause the beer to go flat and spoil quickly if you don’t finish the keg within that time frame.

What temperature should I store my keg?

The recommended temperature for storing draft beer is 38 degrees, according to the Draught Beer Quality Manual. This is the optimal temp for freshness and pouring. In addition to affecting the freshness of your beer, warm beer also has the tendency to pour foamy. Always make sure your keg is properly chilled when pouring. 

You cannot store a keg of beer at room temperature. Bacteria can form in beer if its temperature rises above 50 degrees. Since it is a liquid, keeping beer at too cold of a temperature is also a no-no. Beer will freeze at around 28 degrees, depending on its alcohol content.

We hope this information will help you when deciding to purchase your next keg of beer. One other thing to consider is choosing the right size keg. Check out our Guide to Beer Keg Sizes to learn how much beer comes in the various types of kegs that are available. Knowing how much beer you need for an event or how much you consume at home will help you select the right keg and reduce the chance of beer going to waste from spoilage.