Question about co2 absorbing

Just curious about this, yesterday I finished my disaster of a NEIPA transfer to (2) 3 gallon kegs ( splitting the batch with my son). I then dry hopped the kegs, purged with co2 a bunch of times, then pressurized to 12 psi.

I checked for leaks with my starsan spray bottle , looked good. So I shut the tank valve off and left the lines and everything else under pressure attached to the kegs.

This morning I looked at the guage and it dropped to about 8 or 9 psi.

I don’t know much ( anything) about the physics of the beer absorbing Co2, so would you think this pressure drop is the beer absorbing a bit of the gas, or is it a leak somewhere ? Beer temp is at about 70 for a 5 day dry hop before I cold crash and carb.

I cranked the pressure up to 22 and again checked for leaks but didn’t detect any.

Thanks !


Probably absorption Tom. I’ve noticed pressure drop in kegs I’ve gassed and let sit disconnected that I know are not leaking. I’m pretty leak paranoid so one practice I’ve picked up from reading other posts is to pressurize to about 30 to set the lids on my kegs. Good luck with the NEIPA!

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Thanks! I am also a maniac about leak testing. As far as the NEIPA… We will see, if it comes out of my perlicks like sludge …I will prob dump it down the driveway and just go back to my normal IPAs .

I was thinking last night wouldn’t it be nice to have a mesh liner in the fermentor that could be lifted out. I guess that would cause all kinds of other issues. The big dump valve on the high end conicals would be helpful I suppose.

As CO2 is absorbed into solution pressure in the head space will lower until there’s equilibrium. When you’re carbing your beer it’s best to leave the CO2 on.

Expect some trub in the first pour so you wan’t be disappointed IF there is some. How much there may be just depends how clean the racking was.

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My most recent IPA was DH in the keg with more than hops I’ve used before. First couple pints were pretty sludgy but oh so fragrant!

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Yes I always leave the gas on when carbing, but I am dry hopping at 70 deg so I figured not much carbing happening at that temp. I was more curious about checking for a slow leak but it makes sense some of the co2 will be absorbed.

I will give it a couple of pints anyway to clear out. I think it should be ok, but by screening the “pour” I prob oxygenated the crap out of it. I am hoping that the yeast will find a little more work to do and possibly reduce the oxygen effect while at the higher temp before I chill and carb it.


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