View Full Version : Another Stupid Carbonation Question

02-10-2015, 08:16 AM
I've placed this question in the stupid section because clearly I'm missing something and/or I'm dong something stupid.

We're a new 10 barrel brewery set up predominantly focussing on keg beer. Having come from a predominantly cask background, the way I've ever approached keg before was force carbonating each container individually, with the obvious inconsistent results.

Having moved to a new brewery, I've been researching method for bulk carbonating our entire batches. We have 2 x 10 bbl unitanks and 1 x 20 bbl unitank, plus the option of 5bbl open fvs and 5bbl grundy tanks. (I plan on being busy)

Problem I am having though is what seems to be retaining carbonation. I've brewed into the unitanks, sealing the vessel when approaching final gravity with a few points to go. Cool to diacetyl rest, pressure builds to around 1 bar before I crash cool to 0 - 0.5 degrees celsius, leave for a couple of days and collect/disgard the yeast. I don't get much carbonation of the beer at this point, so I attempt to top it up by running from the racking arm and back up through the bottom via an inline carb stone. After a few hours of doing this slowly, I have carbonation at a level that's reasonable, though I can only see it if I drop all the pressure out of the tank and pour into a glass. If I don't and pour straight in to a glass, obviously, I get just foam. If I keg, (this is done manually, via counterbalance), even though it's not foaming (by the looks of the racking line) as soon as I dispense on our test set up, although it pours perfectly fine, I have little carbonation or if I do, it last arounds drinking around 2/3rds of the glass. (Currently kegging into KeyKeg and EcoFass)

The something, or several things, that I'm clearly missing, and I'm scratching my head to figure out why.

My thoughts so far are:

that either the pressure when kegging, is knocking the carbonation out of it.
that my stone is too small/fine (it's only an inch barb and either I need to run through it for longer or increase the size for more surface area)
or that the perceived carbonation when dispensed under no pressure, is just from agitation and it really isn't carbonated at all, which mean's I'm missing the point entirely altogether.

Any suggestions, would be gratefully received. I'm completely willing to take anything on board and if it involves different processes or equipment, then so be it. I just want to get it sorted, obviously.

Cheers for your time.

TL Services
02-10-2015, 11:38 AM
Whats sort of beer volume do you have in your tanks after yeast removal? If there is a relatively large headspace in the tanks, then much of the CO2 from carbonation will simply be filling this rather than staying in solution.

At around 0 deg C & atmospheric pressure you should see around 1 - 1.5 volumes of CO2 assuming the headspace is pretty much all CO2.

To get up to the ~2.5 volume level you would need to see at least another 0.5 Bar pressure, again from CO2.

Once you have carbonated, it would be useful to leave the tank for at least 30mins before sampling to allow the additional CO2 to become properly dissolved.

I'm not that far away from you, so please do send me a PM if I can help!

02-11-2015, 01:55 AM
Calculating the head space is difficult as we've no sight glasses on the tanks. The tanks is labelled at 2000l, so with 10bbl liquid going in, I would about 1600l after yeast removal. I'll try getting the pressure up to above 2 bar and I'll also send you a PM.

TL Services
02-11-2015, 02:18 AM
Just to avoid any confusion, the 0.5 bar increase I mentioned in my previous post equates to a reading of 0.5 bar gauge, ie. a total of 1.5 bar absolute.

03-24-2015, 11:33 AM
When sampling, keep your pressure at the serving/kegging pressure (typically around 12psi). Make yourself a sample hose with a suitable tc/hose barb and a picnic tap. Make the hose as if you are tapping the tank for direct pour (ie. cut to length to balance for pressure, temperature and hose resistance). Let the beer sit for a while after pressurizing has completed before testing. When you're ready to sample, clean and sanitize the hose/tap, sani the racking arm port and attach.

03-24-2015, 02:33 PM
The standard size carb stone for a 10BBL unitank is 4" and 6" for 20BBL at a minimum. It might be that simple of a fix.

08-12-2015, 08:12 PM
I use 7bbl Bright tanks for carbonation and settling. Our carb stone is about 6 inchs. Our PRV opens at around 15psi. We set our CO2 regulator for about 21psi, to take into consideration the pressure of the beer. This is just enough to cause the PRV to open slightly. This allows for the CO2 to move though the solution. If the CO2 can't more though the solution then nothing is happening. We do this for a few hours. We have never had a single problem since we started using this technique.