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CO2 volumes calculator

If I missed this topic already posted, my apologies… But I didn’t come across anything, so here goes!

I kegged my first beer, an American cream ale, I would like to shoot for about 2.5 volumes of CO2. My keg is at 34 degree and has been cold crashing for almost 3 days now…

The online CO2 volumes calculators say that I should set my pressure between 9 and 10 psi, but none of them say how long to sustain that pressure. Anyone have experience with this? I don’t want to shake the keg and over carb, I was going to flip it upside down so the gas line pushes up through all the beer.

Thanks in advance for your help! Hope everyone is well in these crazy times

If you set the regulator at 9-10lbs and just leave it there it will carbonate the beer until the pressure equalizes to that and the regulator should stop the CO2 flow. I always figured with out any help form carbonation stones, high pressure first or shaking the keg about two weeks usually does it. Your 34° temp will help the process.

You might want to serve the beer at a little higher but turn it down or disconnect the gas after so it won’t carbonate it higher.

Thanks for the info, I really appreciate it! I just can’t wait to try this beer lol

I always do what @hd4mark does, it is the “set it and forget it” method. You can adjust it upward or downward a bit depending on your system…it does take patience not to keep sampling it during the 10 - 14 days or so it takes to fully carbonate.
Here is a useful, oft provided link on carbonation/ hose length/ settings etc based on your system:

The CO2 actually dissolves into the beer, much like sugar or salt dissolve into water, but it takes some time. The carb chart tells you the final volumes you will reach if given enough time. It takes a week or two with the CO2 maintained at the indicated pressure.

CO2 transfers into the beer at the surface where gas and liquid touch each other. Increasing how much they touch speeds up the process. You can speed up the process by shaking or rolling the keg. Bubbling the CO2 through the beer by turning the keg upside down won’t help much.

Setting the pressure higher than what the chart says does help to force the CO2 into the beer a bit faster but that will risk over-carbonating. The only way to over-carb the beer is to set the pressure higher than what the carb chart says for the given temperature. At the indicated temp and pressure for the desired volumes, you can not overcarb, no matter how much you shake, rattle and roll the keg.

Thank you all, this was very helpful!

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Food for thought… Hook up your gas line (flared fittings,yes?) to liquid disconnect… I’d put it at even 20 PSI’s… Yes, do shake it… Then, once it’s done accepting CO2… Disconnect and then put your gas back as it was… Hook up the lines and pour a few pints… It may be foamy for a few pints, but it’ll settle down and you’ll be imbibing sooner rather than later… :beers::mask:

My SOP is to put keg in kegerator and crank CO2 to 30 psi for 24 hours, then drop to 20 psi for 2-3 days then sample. My serving pressure is right about 8 psi for my kegerator. I’m typically not patient enough to wait 3 weeks to carb. If I had a keezer setup where I could carb two and serve two, I’d definitely do that option to get them ready while I’m workin through the active kegs.


I look at that chart, WT_. I understand #s on the left. The lbs of the regulator on top. What are the #s in the middle mean?

The numbers in the middle are the volumes of CO2 you should end up with at the end, if I’m not mistaken.

Sounds good, I’ll try this method probably. I appreciate it

I got beer in my regulator trying this, luckily I have two regulators… Not sure what I did wrong.

Yep. Correct.

By pass the check valve? It won’t let a higher pressure feed back into the gas line.
I’m sorry you got something more to look at now… This has worked for me so many times…

How do you get to those #s?

This article gives a reasonably easy to follow explanation. Master the Action: Carbonation - Brew Your Own

I’m not sure if you are asking how the Volumes of CO2 are derived from the chart? Cross reference your beer temp by psi of CO2 at equilibrium. i.e. A keg at 32* F stable (at equilibrium) for two weeks at 12psi of CO2 will have 2.9 volumes of CO2.
Now if your asking about the math behind the table, I could have helped you back in the early 1980’s when I tutored freshman chemistry for beer money, but a quick glance at millimoles and avagadro’s number tonight was enough to deter any attempt on my part to go any further!

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Good time to put on the coasters brakes!!! :roll_eyes::mask:

Not a problem, it was an older regulator, not sure it has a check valve. I’m using a tap rite regulator now, which I think all have check valves. I’m going to tear the other one down and clean it up, should be good to go.


The math behind the table… holy sh–!:tired_face:

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