Why might one keg develop more pressure than the other when on same manifold?

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Nov 12, 2018
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Last night I noticed my Pale Ale was quite foamy and was pouring much faster than the NEIPA I have in the same kegerator. I gave a short pull on the PRV of each keg until I heard the CO2 bottle refilling the co2, the pale ale had a whole bunch of pressure behind it (my rough guess would be 20-30psi judging by the sound) compared to the other keg(my guess is right around the 8 psi the regulator is at). The keg is halfway empty(or full?) and the first half poured issue free. The kegerator is a 2 corny mini fridge conversion, both kegs are fed from the same manifold and co2 is set at 8 psi. Not sure how this happened, I did notice frost on that keg last night so I upped the fridge controller a hair. The keg has been cold the entire time and the beer tastes fine so I doubt fermentation restarted or infection. Any ideas?


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Dec 30, 2015
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Farmington Hills, MI
Two thoughts come to mind, both related to temperature.

One is maybe you have a temperature difference inside your kegerator. The one keg got colder, so at the same 8 psi, it equates to a higher vol of CO2. The frost on the outside is a clue and a good idea that you bumped up the temperature a bit. Or get an air circulation fan to get more equal air temperatures.

The other thought is if the keg that built up pressure had less beer in it, it would be more prone to the temperature cycling, and thus more susceptible to absorbing more CO2. If this is the case, same fixes as mentioned above should give you more stable temperature and thus the smaller volume beer won't swing as widely in temperature