Force carbonation calculator

[poptarts]

Is there a calculator for kegging similar to the bottling carbonation calculator. I want something that I can enter beer temp and volume and it tells me how much psi i have to fill the head space with. Not a set and forget or a psi to CO2 volumes chart. But one where it would be like

beer is at 65 and 5 gallons
fill head space with 45 psi then remove from gas.

Then over say a week or 2 it would equalize to the correct volumes that I wanted. This would be nice so I could quickly fill the head space of a keg in like 10 seconds, then just toss it in the cellar, then after a month or whatever hook it to the gas and it would be good carbonation level and ready to drink. Hope this makes sense. thanks for the help.

 

[day_trippr]

There are plenty of charts, tables and calculators for force-carbing beer.
There's our favorite carbonation table, and here's one of the multitude on-line that works and also provides the "carbed to style" volumes...

Cheers!

 

[poptarts]

Thanks... but it appears you didn't read my post. After thinking and trying to do the math myself it appears you would have to know amount of beer and amount of headspace, so that could be tricky.

 

[day_trippr]

Thanks... but it appears you didn't read my post. After thinking and trying to do the math myself it appears you would have to know amount of beer and amount of headspace, so that could be tricky.

Guilty. I've poured a couple already and reverted to skimming. My bad

Anyway, you have gas interface area, head space volume, gas pressure, beer temperature, height of the cylinder - and beer gravity to consider, just for starters. Seems like a hella lot of math when two weeks plus a few days at the appropriate pressure will pretty much guarantee a perfectly carbonated five gallon in a corny keg...

Cheers!

[edit] But...for the sake of furthering the discussion...Let's say you filled a corny with exactly 5 gallons of beer, leaving exactly 1/2 gallon of head space. You already know you'll need 2.5 times 5 gallons or 12.5 gallons of gas at STP to carbonate the beer to 2.5 volumes. Let's also stipulate the beer will sit in your cellar at a constant 60°F, which would require CO2 at 23psi until equilibrium is reached to achieve 2.5 volumes.

So...if gas density increases linearly with pressure...you'd need to fill that half gallon of head space with CO2 at 12.5/.5 * 23psi or 575 psi.

"Kids, don't try this at home!"

 

[KegWrangler]

It won't work to fill the head space with a high pressure because that pressure would be too high.

If you're trying to deliver ~2.4volumes CO2 and the headspace in a 5 gallon keg is 0.125 gallon and the residual volumes from fermentation is about 0.9 volumes then you'll need

10psi/volumes * 5gal/0.125gallons*(2.4volumes-0.9volumes) ~600psi. BOOM!

Most can get the keg to equalize at ~2.4 volumes at 30psi for 24-36 hours at 40F then disconnect and wait 2-3 days.

Try 45psi if at room temperature and see where that gets you.

 

[poptarts]

pretty sure your guys math is way off. Look at beer bottles, they have say 10% head space, the same amount we are talking if there is 5 gallon in a 5.5 gallon keg. the psi in the headspace doesnt get anywhere near that much.

 

[day_trippr]

pretty sure your guys math is way off. Look at beer bottles, they have say 10% head space, the same amount we are talking if there is 5 gallon in a 5.5 gallon keg. the psi in the headspace doesnt get anywhere near that much.

Entirely irrelevant, as the beer was carbonated BEFORE it was put in the bottle.

Two people got to essentially the same explosive answer.

Don't like it? You do the math...

Cheers!

 

[WeHeavy]

Why don't you just prime the keg with corn sugar and stick it in the cellar. That would be the easiest. If you don't like corn sugar and prefer gas then buy an extra C02 setup for the your kegs in the cellar

 

[poptarts]

Entirely irrelevant, as the beer was carbonated BEFORE it was put in the bottle.

Two people got to essentially the same explosive answer.

Don't like it? You do the math...

Cheers!

Pretty sure my beer is going to have the same CO2 level if I'm racking to a bottling bucket or racking to a keg.
and working on it, sorry to offend master wont happen again master.

 

[poptarts]

Why don't you just prime the keg with corn sugar and stick it in the cellar. That would be the easiest. If you don't like corn sugar and prefer gas then buy an extra C02 setup for the your kegs in the cellar

Too cold in the cellar and I'm a cheapskate.

 

[day_trippr]

Pretty sure my beer is going to have the same CO2 level if I'm racking to a bottling bucket or racking to a keg.
and working on it, sorry to offend master wont happen again master.

Don't do that.

You asked a question and got two answers that you either don't understand or choose not to acknowledge, but you have no solution of your own to provide as a counterpoint.

So, where you going to go with this now?

Cheers!

 

[poptarts]

So lets say the keg is 5.5 gallon and we have 5 gallons of beer. the beer has .9 volumes already from fermentation. wee need 1.5 or so more volumes to get 2.4. for sake of argument lets say at our temp this will equalize to be 12psi for the full keg.

12 * 11 = 132psi if the beer has 0 volumes but it has .9 so we really only need 12 * 1 for the headspace and ~10*10 for the beer so 112 psi is what I'm calculating. and even that feels like twice as much as needed to me.

 

[day_trippr]

Lost this thread along the way.

So KegWrangler's solution allowed for fermentation carbonation and was based on a 1/2 quart headspace - roughly one quarter of your half gallon.
And 4 times your 112 puts you roughly back in his ball park.


fwiw, when new, the PRVs on ball lock kegs were rated somewhere between 65 and 85psi (the kegs were rated between 135 and 150 psi).

So unless you can come up with the math that lets you accomplish the objective with a pressure below the PRV "pop" point, it's still Game Over...

Cheers!

 

[poptarts]

Yea, I'm sucking it up and getting a Y slitter with like a 10ft gas line so ill just keep a keg on gas in the cellar for a couple of weeks till its crabbed.

 

[day_trippr]

Good deal. I really think you'll appreciate the investment.

It's all about the pipeline!

Cheers!

 

[poptarts]

indeed it is