I have a kegerator setup with CO2 and a tap. Once a keg has been put into the kegerator, how long will it stay good? What can I do to ensure that I get the longest life possible out of a keg once it's been tapped? Is there some way (aside from the flavor changing) to know that it's gone bad?

Is the answer to this question different for homebrew kegs than for commercial kegs?

  • My local brew club just had a lecture about this. A major concern was the loss of flavor in some beers. Aromatics may be lost to the head space in the keg if they sit too long.
    – Wulfhart
    Commented Jun 8, 2012 at 17:50
  • A keg in my fridge last me 2 weeks. have a co2 setup at 10psi. If it goes more than 2 weeks there is a problem. I am not drinking enough.....
    – user3920
    Commented Oct 16, 2013 at 2:07
  • I brewed a lager almost 4 years ago. I never let oxygen touch it and I keep it in a cool place. I have heavy duty seals on it and a clear beer draught system instead of a dip tube inside. I drink about 2 liters of it a year, and i still have about 16 liters left, depending on trub. Still tastes like fresh bread. The finish is becoming kind of like aged champagne, but the beer still has some residual faint sweetness. The keg is naturally over pressurized a bit, so it pours under its own power. BTW I am amazed its drinkable. Stunned. But it is.
    – DaFi4
    Commented Feb 21, 2019 at 13:09
  • How many licks does it take to get the center of a tootsie roll pop? The world may never know. At least not at my house :-)
    – Wyrmwood
    Commented May 19, 2021 at 12:43

4 Answers 4


As you drink the keg, you're replacing the beer in the keg with CO2. The CO2 isn't going to stale your beer. As long as you are keeping the pressure in the keg high enough to ensure that the carbonation doesn't dissipate into the keg's head space, the beer should stay tasty for quite a long time.

Unlike kegerators, hand-pump kegs replace the beer with air, which causes staling and allows the co2 in the beer to evolve out, leaving you with flat beer.

If you're not going to drink from the keg for a while, it's a good idea to disconnect it from the intake/outake lines. Just make sure you've pressurized the keg appropriately, then disconnect it.

  • 1
    Pressurizing the keg appropriately basically means connecting it to a 15 psi CO2 supply and allowing the pressure to equalize? How long have you kept a keg this way without it going bad? Commented Jan 20, 2011 at 16:53
  • 2
    It depends on the amount of carbonation you want in the beer and the temperature you're serving at. 15 - 20 is a good estimate, but if you want to really exact, take a look at this nice guide to kegging: www.beernut.com/zen-cart/pub/kegging.pdf As long as your keg holds pressure and your sanitation was good, you can hang on to it for months and months. I know of home brewers who have kept beers for years.
    – Hopwise
    Commented Jan 20, 2011 at 17:14
  • I just tapped a 3 year old lager and it still tastes fine. I just dont let any oxygen in. I drink a few liters every year and always throw out whatever was in the "dip tube". I use a clear beer "dip tube" so it grabs beer from the top.
    – DaFi4
    Commented Feb 21, 2019 at 13:05

If the beer is being kept cool and you are using CO2 to push (which I assume you are) then it can last for months. I think the longest I've ever had a Corny keg last is three months, but that was finishing it, not spoilage. Kept refrigerated, sealed and under CO2, it should last longer than it takes you to drink it.

The one thing you may want to keep aware of is the cleanliness of your taps. The taps and lines will be dirty long before the keg goes bad or runs out. Regular cleaning (about once a month) is necessary. Dirty taps and lines can make a good beer taste bad.

  • 3
    Good point about the taps and lines. Cleaning beer lines is the bane of home kegging.
    – mdma
    Commented Jun 4, 2012 at 8:26

Do you know what Biogon is? Great mixture of CO2 and Nitrogen. We use it in Czech Republic, but I do not know if it is available in the USA. CO2 keeps the carbonation, Nitrogen preserves it, so it is a great combination.

I think it is called Mixed Gas in your country

  • 1
    Most places in the USA this is called "Beer Gas". It was recommended that I do not need this except with heavier beers like stouts and porters which need the additional pressure. Commented Jun 4, 2012 at 12:57
  • We use it here mainly for lagers and pilseners. 10+ Plato.
    – Petr
    Commented Jun 4, 2012 at 16:22

I've seen a 15.5 gallon keg of beer be good over a year later. Kept in house at room temperature. Not just acceptable, but just as good as when it was kegged.

  • Was this after it was tapped? Or between being kegged and being tapped? Commented Jan 21, 2011 at 19:47

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