I have a very basic kegging question that I can't seem to find an answer for: I kegged an IPA last week and have been using the "set and forget" method to carbonate. My question is: when I reach my desired carbonation level, do I shut off the CO2 supply when beer isn't being served from the keg, or do I keep a continuous flow in the keg at all times?
Continuous flow. By not having constant pressure on it you'll invite flat beer. What is your pressure, temperature, line length, etc? I guess you're asking this because you think you'll waste CO2 when you're not doing an actual pour? If you have a leak in your keg, then yes, you will waste CO2. If no leak then you're not wasting CO2.
Shooting for 2 volumes, so I've been running 6PSI @ 39 degrees. 3 feet of gas line in, 5 feet for liquid out. My concern wasn't necessarily with wasting CO2, but over-carbonating the beer once it hit the 2 volume mark. But I assume that could only happen by upping the pressure, therefore raising the equilibrium level in the beer, correct?
The goal is to have a balanced system, ie a system that requires the same amount of CO2 used to carbonate and to serve the beer. To do this you adjust your liquid line length so that the resistance of the line, faucet, etc reduce the pressure to 1-0 psi from your input pressure, which should be equal to your keg pressure so that you don't slowly add carbonation nor slowly decrease carbonation.
Good stuff. Seems like I've read plenty of posters claiming that PSI needed to be increased when serving to counteract the drop in pressure, but your answer makes plenty of sense. Thanks!
The length of the gas line doesn't matter, actually. The gas stabilizes after it meets equal resistance on the other end of the line (when the beer is saturated with CO2 of equal pressure). I have 39F 8' of 3/16'' ID beer lines and I set mine for 10 PSI. Most importantly, do what works. I'd rather have an under carbonated beer than half a beer and a bunch of foam. As @jamescain said, it's about balance. The pressure you serve at both keeps the beer at the proper carbonation level and is a positive pressure that pushes the beer through the lines. You shouldn't have to fuss with this pressure once your beer is carbonated.
Right now, I have 1 of 4 taps shut off at the manifold because I've got a leaky poppet/keg...doesn't seem to make much difference.
The 'forget it' half of the 'set it and forget it' method is to be taken literally. You set the pressure according to the charts, then forget about it until after the keg kicks. That's the beauty of this method. As long as the temp remains constant, the lines are the correct length, etc, you'll have fine pours for the duration. And you'll p*ss off all your know-it-all college buddies who know exactly how to tweak the pressure to 'fix' the bad pours as the party progresses (mount the regulators out of reach or lock the kegerator). Those are usually the guys asking for advice on how to fix foaming issues. The usual (correct) response is some variation of 'stop touching the damn regulator!'
