How to maintain carbonation profile??

[ace0005]

So I've been kegging in my keezer for about 1.5 years now, and I want to address the last real mystery of the brewing process. I still don't know how to carbonate to maintain carbonation volumes to fall within stylistic parameters. I understand that there are brew calculators out there that tell you what PSI to set your CO2 tank at to achieve a specific volume at a specific temperature.

What I do not understand is how long I'm supposed to maintain the pressure in the keg. I imagine that if I leave a keg pressurized at 10 PSI to achieve 2.6 volumes, the beer will continue to absorb additional volumes of CO2 and exceed the style specific volumes, until it becomes saturated and can no longer absorb more CO2. Thus, wasting precious CO2.

OR, is it a case of I need to maintain 10 PSI to keep the beer at 2.6 volumes indefinitely?

Finally..... i have a 3 keg keezer. Can I customize the pressure for each keg individually? If so, how?

 

[day_trippr]

If one chooses the right combination of temperature and pressure using, for instance, our favorite carbonation table, the carbonation level at equilibrium is a known quantity. The carbonation will be no more or less than that calculated value - no matter how long the beer sits at that pressure and temperature.

The only unknown is the time to reach equilibrium, and that is dependent on additional metrics like the area of the gas/beer interface and the depth of the beer. And while there have been attempts to quantify that time based on cornelius style kegs (there's a table around here somewhere) I simply allow 2.5 weeks minimum to reach equilibrium...

Cheers!

 

[ace0005]

If one chooses the right combination of temperature and pressure using, for instance, our favorite carbonation table, the carbonation level at equilibrium is a known quantity. The carbonation will be no more or less than that calculated value - no matter how long the beer sits at that pressure and temperature.

The only unknown is the time to reach equilibrium, and that is dependent on additional metrics like the area of the gas/beer interface and the depth of the beer. And while there have been attempts to quantify that time based on cornelius style kegs (there's a table around here somewhere) I simply allow 2.5 weeks minimum to reach equilibrium...

Cheers!

Thank you very much for this! Really seems like a straightforward process. One last question, and only for shits and giggles, is there a way to measure the volumes of CO2/Beer? I don't think that I would ever measure. I'm also curious to know if the normal commercial craft brewery would even bother to measure CO2/Beer.

 

[SanPancho]

Thank you very much for this! Really seems like a straightforward process. One last question, and only for shits and giggles, is there a way to measure the volumes of CO2/Beer? I don't think that I would ever measure. I'm also curious to know if the normal commercial craft brewery would even bother to measure CO2/Beer.

there's a pinprick tester. it punctures the can or the bottle top and takes a reading. pretty basic in terms of tech.

one thing i'll also note, you'd do well to remember only two things when it comes to carbonation-

1- there is no such thing as pressure without temperature.

you cant have one without the other. pressure is always measured at a particular temp.

2 - in terms of carbonation- or a gas in a liquid- if you know the temp and the pressure then you have the MAX volume.

anything other reading is the result of an error somewhere- leaky gasket, temp is off, pressure reg is innacurate, not enough co2 in tank, etc.

whenver something seems off its usually an error in temp/pressure, or somethings busted/leaky/etc.

 

[day_trippr]

One can get a feel for keg carbonation level by disconnecting the gas supply, momentarily relieving the pressure in the keg head space, then plugging a pressure gauge on the keg gas post. Given enough time the head space pressure will rise to reflect the current volumes of CO2....

Cheers!

 

[dwhite60]

I've found leaving the caps on my bottles pretty much assures ...........

Sorry.

 

[CascadesBrewer]

So I've been kegging in my keezer for about 1.5 years now, and I want to address the last real mystery of the brewing process. I still don't know how to carbonate to maintain carbonation volumes to fall within stylistic parameters.

Do you have secondary regulators on the gas side that let your control the pressure to each keg? If that is the case, then you just leave one keg at 14 PSI, another at 12 PSI, and another at 10 PSI (whatever PSI a carbonation chart says based on the target volumes and beer temperature). You will also need lines to support pouring beers at different pressures. I think the only real issue with lines that are too long is a slow pour, but if your lines are too short (they don't have enough resistance) you will get foamy pours and much of the extra carbonation in the beer will be forced out.

With my setup I can connect 4 kegs, but I don't have any secondary regulators so they are all at the same pressure. I just serve out of picnic taps with 5-6ft long 3/16" lines. I find that around 12 PSI is the sweet spot for my system. It pours a little fast but I can get a good pour and control the head. If I push that up to 14 PSI, I end up with foamy pours that are less carbonated than I would get at 12 PSI.

Honestly, running all my beers at 12 PSI (around 2.6 volumes) has not been much of an issue for me, even with carbonated water on tap. I can turn off gas lines if I want to burst carbonated a specific beer at a higher level. I have also been bottling some Belgians that I want to push up to the 3 volumes level.

 

[camonick]

What I do not understand is how long I'm supposed to maintain the pressure in the keg.

From the time you attach the gas, until the time that keg kicks. Determine the pressure you need for the desired volumes and don’t mess with it until the keg is empty. You adjust the way the beer pours with the lengths of your liquid lines. If your system is leak free (which it should be), the gas should be attached the whole time and never adjusted. If you’re running secondary regulators to each keg, set the tank regulator at or above your highest pressure and throttle the pressure at each secondary. I supply all my kegs with the same pressure and I’ve honestly never changed my regulator since I put it in service and determined it was set properly.

 

[ace0005]

Do you have secondary regulators on the gas side that let your control the pressure to each keg? If that is the case, then you just leave one keg at 14 PSI, another at 12 PSI, and another at 10 PSI (whatever PSI a carbonation chart says based on the target volumes and beer temperature). You will also need lines to support pouring beers at different pressures. I think the only real issue with lines that are too long is a slow pour, but if your lines are too short (they don't have enough resistance) you will get foamy pours and much of the extra carbonation in the beer will be forced out.

With my setup I can connect 4 kegs, but I don't have any secondary regulators so they are all at the same pressure. I just serve out of picnic taps with 5-6ft long 3/16" lines. I find that around 12 PSI is the sweet spot for my system. It pours a little fast but I can get a good pour and control the head. If I push that up to 14 PSI, I end up with foamy pours that are less carbonated than I would get at 12 PSI.

Honestly, running all my beers at 12 PSI (around 2.6 volumes) has not been much of an issue for me, even with carbonated water on tap. I can turn off gas lines if I want to burst carbonated a specific beer at a higher level. I have also been bottling some Belgians that I want to push up to the 3 volumes level.

I just purchased a secondary regulator..... got a great deal on Ebay .... I bought a brand new Kegco LH-54S-3 for $47 after promos. My wife can't even get mad at me!! I have a 3 keg keezer setup, and it's perfect for my needs. I figure that if I'm going to start entering beers into competitions, I should probably have a way of ensuring that the carbonation is correct.