CO2 - where does the pressure go?

[trustyrusty]

Sorry if this is a dumb question...

I am looking at the 'shake and back method'...the keg is say at 50 psi and as you shake it PSI drops as CO2 is absorbed it the beer. I cannot get my head around that the pressure drops, surely the pressure is still there in the keg. Sometimes if a beer is bit flat I will put up to 40 psi and leave, PSI has dropped but beer is carbonated and as you open tap it comes out as pressure is there but is not shown on the reg... Something I have missed...

Thanks

 

[DJ_L3ThAL]

It gets absorbed into solution. The properties of CO2 dissolved in liquid as opposed to as a gas are different. Less gas is in the head space once you shake it that is why the pressure drops.

 

[scomet]

You answered your own question the C02 is absorbed into the beer, it goes into solution. Take the screw top off a bottle of carbonated drink and put it back on then take it off again - no pressure, put it on again and shake it up... pressure; get it? Thats what you have to think about getting your beer to pour without foam, it can take a bit of getting your head around Cheers TR