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Old 08-08-2012, 10:04 AM   #1
kenpotf
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I've got a keg issue where it's slightly overcarbed. It's sitting at 13.5 and should be around 11 - 11.5. I've purged the keg completely and my gauge shows 0. I then turned up the regulator to 11. If I look at it an hour later, it will be back at 13.5. I'm pretty sure that it's because of what's already in the keg and not just including head space? I tried last night to turn it down to 8 for grins and woke up this morning to 13.5 again. How can I get this thing to purge all of the co2 that's already in it or at least get it back down to 11? Can I turn the temp up on the keezer to get this to even out a bit? It's sitting at 40 now according to my thermostat which does seem to be on the caution line in the chart. Maybe I should turn it up a couple of degrees?

Thanks!

 
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Old 08-08-2012, 11:48 AM   #2
zachattack
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Well if you don't let some of that pressure out, how do you think it's going to go down? A regulator steps pressure down from a high source (tank) to your keg, but it can't pull the dissolved CO2 out of your beer. You need to unhook the gas disconnect and start yanking on the relief valve every time you walk by. After a couple days, hook up the gas at 11 PSI and go from there. Or you can leave the regulator set at 11PSI, and invite some friends over for a few slightly overcarbed beers. If you draw enough beer out of it the pressure should drop a bit, and over the next week or two as you continue to drink the carbonation should even out.

 
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Old 08-08-2012, 11:58 AM   #3
brycelarson
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yeah, just keep venting it. There's a lot of CO2 in the beer - as you release the head space that CO2 will come out of the beer and re-balance the pressure. Each time it'll be a bit lower - the more head space the faster it'll go. If it's a mostly full keg you might only be losing a small fraction of a volume of CO2 each time you purge it.

It'll take time. I would remove the CO2 input all the way until you get down to your target pressure. Just close your valve and dump pressure a few times a day.

It'll get there.

 
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Old 08-08-2012, 02:25 PM   #4
Misplaced_Canuck
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Ever taken a 2L bottle of Coke/Sprite and taken a glass from it? It's obviously "depressurized" when the cap is removed, right?

Then you put the cap back on, and the next day, the 2L bottle is still hard (though not quite as much). That's happened to you, right?

That's called "degassing". CO2 gets removed from the liquid and fills all available space until a balance is reached. That's your PSI going back up.

The same thing is happening in your keg.

If you were at 13PSI, dropped the regulator to 11PSI, and vented, you've only removed a small amount of CO2.


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Old 08-08-2012, 03:18 PM   #5
kenpotf
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Thanks! I took the gas off at one point and released the pressure....shook it, and released more pressure. I think I like the idea of shutting the gas off completely and venting it over the next couple of days. I'll give that a shot and see what happens. I turned up my keezer this morning from 40 - 42 since 12.5 seems to be a decent pressure for that temp in hopes that it would level out a little. For some reason though, my ambient temperature is reading 38 by a taylor thermometer in the keezer and it's reading 32 by my johnson controller. Do you tape your probe to the keg as well? Currently, I just have mine hanging...

 
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Old 08-08-2012, 05:24 PM   #6
zachattack
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I'd say most of us have the probe in/on something with a bit of thermal mass (keg, bottle of water, etc.) Not an original idea, but mine is inside a white labs vial that's filled with sand. Some thermal mass, but no worries about water ruining the probe. Works great so far!

 
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Old 08-09-2012, 08:03 AM   #7
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Quote:
Originally Posted by kenpotf View Post
I turned up my keezer this morning from 40 - 42 since 12.5 seems to be a decent pressure for that temp in hopes that it would level out a little.
It doesn't work that way. Raising the temp isn't going change the amount of gas dissolved in solution, it's just going to increase the headspace pressure from 13.5 to ~14.5 psi. You need to turn the gas off and vent the pressure many many times to get rid of some of the CO2 if you want to change the carbonation level. Or if you want to keep the current carbonation level and get it to pour well, you need to either increase the pressure or decrease the temperature to match the current carbonation.
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