Overcarbonated - Now what do I do?

[Kazi the Younger]

I took the age old advice, relax, don't worry, have a homebrew. Problem I keep having with this advice is my beer turns out like S$%t every time I do this.

So after relaxing and force carbonating by shaking the keg, now the beer is way over carbonated. How do I lesson the carbonation? Shaking the keg and opening the airlock, as if it were a glass, to release some co2?

What have others done if this happens?

[Brew Engineer]

looks like you'll be burping...


the keg. Just bleed off the pressure, and let it re-equilibrate. You don't need to shake it, if you have the time to let it sit and the CO2 to come out of solution.

[Bugeater]

The "rock and roll" method of force carbonating may be quick but you have discovered the downside of that method. Unfortunately, there isn't really a feasible quick method of reversing it. You are doing about all you can do. Once in a great while I get an over carbonated keg. I just disconnect the gas and vent the keg a couple times a day for the next week or so. I also draw a pint now and then to check the carbonation level. This decrease in volume in the keg will also allow more head space to which the CO2 can escape and will allow for faster decarbonation.

When I do the "rock and roll" method I first check the carbonation charts and the temperature of the beer in the keg to find out what the keg pressure should be when fully carbonated. I then hook up the CO2 at that pressure. I roll the keg around with the CO2 still hooked up. When you stop rolling, you will hear gas still entering the keg. When I don't hear it flowing, I begin rolling some more. Again I stop and listen for the gas to flow and then roll again. I keep this process going until I no longer hear gas flowing when I stop rolling. Your keg will be very close to the correct pressure at this point. I then stick the keg in the kegerator to cool to serving temperature before hooking the gas back up. If you hook up the warm keg to gas in the kegerator, the higher pressure in your keg may back beer up into your gas lines and possibly into your other kegs and/or regulator. It will take one or two days for the carbonation to settle out at the right pressure once the keg is cold.

I carb kegs like this at room temperature when I need to serve in only a few days. This requires the gas pressure to be somewhere in the neighborhood of 30 psi. If I don't need the keg that quick, and there is no room in my kegerator for another keg (the usual case around here) I hook up the gas at that pressure and let it sit for a week or so. (It does help having a couple extra tanks and regulators so I can do that.)

Another gadget you should have around is a keg pressure tester. You can get them for under $20 at a couple of the on line suppliers or you can build one yourself out of a gas QD, a CO2 gauge, a few brass fittings and a needle valve. http://hbd.org/carboy/kegpresstester.htm

Wayne

[Kazi the Younger]

I think I see where I went wrong with the "rock and roll" method:

I did it while the keg was at 40 degrees, rather then room temperature. Because I rocked and rolled @ 40 degrees, it would have caused the beer to absorb a lot more co2 then if the beer had been at room temp, correct? It sounds like "rock and rollers" are performing this maneuver @ room temp, and then chilling the beer to serving temp.

I knew something was wrong because no matter how much I shook the keg I could hear an endless stream of bubbles re-entering the solution. Blast!

So now what to do about it? I have a week until I'm serving the beer to others. I will take your advice and "burp the keg" I was reading that some people bringing the keg to room temp to do this, leaving the airlock open the entire time. Others I talk to at my local homebrew shop say just leave it in the fridge, disconnect co2 and "burp" it every once in a while for a day or two. Bugeater, I see this is more what you do. I have a week, so I guess I could get it under control by then. Thanks a lot. I will look into building one of those pressure testers as well. Is it hard?

[bcmaui]

I will look into building one of those pressure testers as well. Is it hard?

I built one last week using that link above. It is one of Bug's "10 Commandments Links of Kegging" link. Well, there's twelve actually, but ten sounds more biblical. All of them make a good read. A couple of wrenches, the parts and some teflon tape are all you need. I torqued the 1/4" flare fittting union too much and had to buy another one, but other than that it took 5 minutes to put together.

[TapItGood]

I force carb all my kegs. I always do it @ about 38 F. My trick is I do it 2 steps. I turn my C02 up to about 30 psi and put the keg on it's side with the gas in at the top and roll the keg vigirously back and forth for just about 3 minutes. I let it sit overnight (hooked to the CO2 @ about 10 PSI) and in the morning I pour a sample to see what the carbonation is like. It's usually carbonated but not fully, but now I know if if it needs just a little more or a repeat of the above. I've have not yet overcarbonated a keg yet so I can't help you with the venting part. Good Luck and Cheers!

[Kazi the Younger]

"I turn my C02 up to about 30 psi and put the keg on it's side with the gas in at the top and roll the keg vigorously back and forth for just about 3 minutes."

My problem is I put it on it's side @ 30 psi with the gas in at the BOTTOM, so it was constantly bubbling and dissolving into solution. That must have been what did it. Blast!

Well I'm going to raise the temp slightly and bleed, bleed bleed. My bro who was a pro brewer said at his brewery they had carb problems all the time and they used to deal with it by forcing co2 into the bottom of the brite tank with the lid off...all that co2 pressure would stir up the who batch and blow off more co2 then would stay in solution.

[Mylo]

"I turn my C02 up to about 30 psi and put the keg on it's side with the gas in at the top and roll the keg vigorously back and forth for just about 3 minutes."

My problem is I put it on it's side @ 30 psi with the gas in at the BOTTOM, so it was constantly bubbling and dissolving into solution. That must have been what did it. Blast!

It doesn't matter if the gas inlet is on the top or the bottom. It's the 30PSI of pressure that is pushing the CO2 in from the headspace - as you splash it around in there. When it's on the bottom - you can hear the bubbles better vs. the sound of the regulator alone. Your problem was just that you shook it at the high pressure for too long.


Mylo