Originally Posted by AllHoppedUp
1. Will the carbonation temp. vs. the serving temp create problems?
2. Will the elevation change create problems?
3. Will the agitation inherent with a 360+ mile journey create problems?
4. Anything else I need to consider?
5. Kind of unrelated, but how do I fix an over carbonated keg? If I bleed off pressure there's just not enough pressure to serve . . . when I turn the pressure back up it's still foamy.
the difference between carbonation temp and serving temp won't be a problem as long as you carb at the right pressure. Since liquid absorbs carbonation at different rates depending on temp, you need to carbonate at a higher pressure. There are calculators on the Internet to figure it out exactly but it should be between 25 and 28 psi depending on style and desired final volumes. When you chill it down to serving temp The increase in absorption rate will allow the gas to dissolve into solution and be properly carbonated.
Your altitude difference is a matter of .05 atmospheres, so it will affect it, but nothing that can't be stabilized with a day at sea level. If you want it to be right on my guess is you could multiply .95 by your desired end volumes of carbonation before plugging it into the carb pressure calculator.
As long as your kegs have reached the correct level of carbonation you can disconnect them from the air and transport them just fine. Once carbonated, the gas in the beer and the pressure of the gas in the headspace are at an equilibrium. As long as the gas can't get in or out of that equilibrium, it will be fine. As someone else mentioned, you might stir up some stuff, but the carb will be fine.
To fix the over carb issue, you can basically do the reverse of a shake carb. Bleed off the air in the keg. Now you've changed that equilibrium by removing that headspace pressure keeping the gas in solution. Gas won't come out of solution right away though, but if you disturb it, it will. Shake the keg, and you'll see the needle rise. This is the gas coming out of solution and starting to fill the head space. When the needle stops rising, you've reached that equilibrium again and pulled some of the gas out of solution. Let it sit a couple minutes, then repeat the bleed, shake till needle stops climbing, rest process until the pressure the needle stops at is your desired psi.
Tastybrew.com has one of the carbing pressure calculators on their site.