I have a keg that was connected @ 15 PSI for 4 days at 75-80F while dry hopping. When connected w/gas, I found no leaks. There is a smidgen less than 5 gallons in the keg.
After a four days, I removed the gas and let it sit for another 2-3 days.
Today, when moving it into the refrigerator, I found it to be depressurized. The pressure release gave nothing.
I’ve got it back under gas, the lid and out post are soaped. No bubbles …
Is it possible the beer absorbed the gas? Does this sound plausible for the lack of gas in the headspace (minor headspace)?
Yep. The beer needs to stay connected for around 2 weeks to carbonate fully to your pressure setting. And then afterward it helps to keep the pressure on the keg, to keep the lid seated.
It’s possible too, but it seemed most likely that the CO2 just got absorbed since it was only connected for 4 days. Best way to test - reconnect to CO2 and spray the keg lid, PRV, and QDs with starsan and look for big bubbles forming in the starsan. If no leaks are noticeable, your beer absorbed the CO2. I’d bet on it.
the co2 will absorb faster when the beer is cold. the colder the beer and the higher the pressure the faster it will carb up. here is a link to a chart: Using a Carbonation Table Pressure Chart
doubt the co2 absorbed in to the beer when it was above 70 F.
It will absorb at 70, just not as much. But 4 days @ 15 isn’t nearly enough to get the beer to saturation. Also if it cooled at all then you also have thermal shrinking of the beer, which will increase headspace slightly.
If there is pressure in the headspace, the co2 will diffuse into the beer as it seeks equilibrium. That’s the Laws of Physics, particularly the Ideal Gas Law.
Beer can easily be carbonated at 70 degrees. It requires more psi (but not more gas) to do so, but even at 15 psi, the beer will absorb the gas in the headspace until equilibrium is reached.
I have a keg with a bad popette (yes I should replace it and I even have the new piece, just haven’t done it yet) when I remove the gas QD it starts losing gas through the post. I can jimmy with the popette and it stops but I don’t trust that keg for long term storage. You could well have a popette with a slow leak. it wouldn’t show up while the gas was connected.
I’ve fixed this on a couple kegs recently, and it can be a sneaky problem. On one of the fixes, the o-ring on the universal poppet was torn, so I replaced the problem with the same problem. Drove me a little crazy.
I also believe that if the keg has relatively low pressure already and then you chill it, you can lose the seal on your lid. That’s my theory, anyway. I’ve moved kegs to the fridge and had them seem like they have no head pressure once they chill. Well carbed, but no pressure.
I’ve found that over time the metal head of the poppit wears away at the post. Had a small leak from several gas poppits and under magnification there were scalloped grooves in the rim where the poppit mates with the post. They would cause the poppit to re-seat incorrectly when I removed the QD.