Just kegged my American Stout last night. Gave it a little agitation at 30 psi, then left it at serving pressure around 8-9psi. First taste, it's great! The only slight thing I noticed I can only describe as "the taste of the smell of an empty keg that has been filed and pressurized with CO2".

Am I right to think this is the flavor of partially carbonated beer and will mellow/balance out in a week at serving pressure?

It's completely tolerable, I don't even remotely mind the flavor, but just wondering if anyone has experience with this?

The IIPA I kegged and carbonated the night before was agitated for around 3-5 minutes at 30psi, but the beer was already cold crashed for a week so it instantly absorbed all of the gas and was perfect and ready to go.

  • That hasn't been my experience. If the brew is otherwise drinkable, longer carbonation times should result in a finer head (i.e. tiny bubbles vs. soda pop type) but no change in flavor. I suggest you may not have cleaned out the keg thoroughly, though you may have sanitized it properly.
    – Glasseyed
    Commented Aug 1, 2015 at 0:28
  • "the taste of the smell of an empty keg that has been filed and pressurized with Co2" My limited experience says that this smell and taste, well, does not exist. Like, at all. CO2 is pretty odorless, keg and rest of the installation shouldn't be leaking any odors either, and I never smelled anything but beer from a tank. Maybe the fact you do is the core of your problem?
    – Mołot
    Commented Aug 24, 2015 at 14:42
  • 1
    CO2 while odourless tends to have an acidic note, which can be perceived on the palate and nose. The OP's issue sounds like probably a cleaning and or sanitation issue. Depending on your process, it could be carry over from another vessel, in your lines, or in the keg itself.
    – John
    Commented Sep 17, 2015 at 21:02
  • How long was it in primary/secondary? Could still be a little "green" with youth and need more time for yeast to settle out.
    – DHough
    Commented Apr 7, 2016 at 15:25

3 Answers 3


You shouldn't taste your keg. If you taste something that shouldn't be there, maybe it's a sanitizer or something that was previously in the keg?

For beers I do, I think CO2 adherence to the beer improves with time spent in the keg. CO2 forced in doesn't seem to absorb as well as CO2 absorbed over several weeks in a cold fridge. Without knowing your recipe, water profile, etc., hard make other suggestions.


Could it be an issue with a poorly cleaned keg? I've noticed off flavors when I've gotten lazy with cleaning seals / poppets etc. before.

Otherwise time in a keg does tend to mellow out the flavor, but if you are tasting keg I'm not sure it will mellow too much more than it is now.


Could try pushing the CO2 out of that beer and re-presurizing over a longer period of time. I do 24 psi for 48 hours. Could try that to get new gas in your beer.

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