Air Bubbles in Beer Line?

I'm kegging for the first time, and am having the normal "too much head, not enough carbonation in solution" battles which everyone seems to go through the first couple times. The numerous threads on this topic have been very helpful.

One question i did have is: should I expect to have air/gas bubbles in my beer out lines? when i first tapped the kegs, i did not see this but now it seems to be getting worse. i have both little CO2 bubbles in the lines as well as significant air pockets (void volume) in the lines.

I'm guessing I have a leak somewhere? Any troubleshooting tips would be greatly appreciated!

-ssb

It's not a leak and it's not air. It's just CO2 coming out of solution. I presume that the lines coil above the kegs and that air is generally warmer. It doesn't take much CO2 to fill that narrow tubing.

Thanks Bobby. So it sounds normal.

I've got the kegs in a refigerator where I have to constantly open/close the door to get to the beer. From what you said, I'm guessing the lines are warming up. When I go to a "tap on the outside" setup, I presume this should be less of a problem?

What pressure are you running? You don't want bubbles (co2) in your beer lines, that's a sign of low pressure and the co2 is breaking out. This will cause foaming.

I had the keg at 22-25 psi for a couple weeks (it's Apfelwein...i like it highly carb'd), then backed it down to 5 psi to serve (i'm using picnic taps). the Apfelwein does foam quite a bit when it comes out. is 5 psi too low? i tried 10-12 psi but it comes gusing out. i'm using about 5-6 feet of 3/16" id tubing. i thought this would drop the pressure from 10-12 psi adequately (2.7 psi/foot), but I haven't had any success so I moved to a lower pressure (where i still get some noticable foam).

FWIW -

I have my system "balanced" (but not per the calculations) based on trial and error. I have 10' or so of line (3/16" ID) on each tap. I carbonate and serve at the same pressure and never turn it down (e.g. true "set and forget") and never get foamy pours on anything I've poured between 10psi (my bitters) and 16psi (my wheats). I've never carbed up to 20+ psi before, but I think my length of line could handle it with no need to drop the pressure.

As for the CO2 bubbles in the line above the keg, I think thats normal due to being coiled (probably has so effect on pressure) or above the keg where the beer is probably a few degrees warmer. I think it would be only natural that some CO2 would come out of solution of the keg is at 40F, but the tubing near my tower is at 50F. Even so, I never even get foamy first pours and I've never had any problems with CO2 bubbles in my line...

southsidebrewer said:

Thanks Bobby. So it sounds normal.

I've got the kegs in a refigerator where I have to constantly open/close the door to get to the beer. From what you said, I'm guessing the lines are warming up. When I go to a "tap on the outside" setup, I presume this should be less of a problem?

Click to expand...

I don't know if it is normal. I have picnic taps and open the door all the time yet there isn't CO2 in my lines. I don't coil the line on top of keg though as I hang the tap on the side of the keg handle. I wouldn't think opening the door to pour a beer is going to warm the lines all that much.

southsidebrewer said:

I had the keg at 22-25 psi for a couple weeks (it's Apfelwein...i like it highly carb'd), then backed it down to 5 psi to serve (i'm using picnic taps). the Apfelwein does foam quite a bit when it comes out. is 5 psi too low? i tried 10-12 psi but it comes gusing out. i'm using about 5-6 feet of 3/16" id tubing. i thought this would drop the pressure from 10-12 psi adequately (2.7 psi/foot), but I haven't had any success so I moved to a lower pressure (where i still get some noticable foam).

Click to expand...

I served my apfelwein at 10 to 12 psi with no problems. Are your serving lines cooled?

the lines are cooled to the extent they are inside the fridge with the keg...no additional cooling. i also try to hang the tap on the top of the keg...some of the line sits on top, but the majority is hanging alongside the keg.

southsidebrewer said:

the lines are cooled to the extent they are inside the fridge with the keg...no additional cooling. i also try to hang the tap on the top of the keg...some of the line sits on top, but the majority is hanging alongside the keg.

Click to expand...

That should be fine, I personally wouldn't run anything at 5psi, that is most likely the cause of your c02 breakout, try turning it up to at least 10psi and see if the bubbles disappear. There's a lot of good info here http://www.micromatic.com/draft-keg-beer-edu/beer-questions/pressure-cid-2455.html that should help solve your problems.

this is my setup just for visual. the beer lines in the picture aren't actually hooked up. the majority of the time i have the tap handles hooked on top of the keg.

Quick update...

I increased the pressure to 12-15 psi and increased my 3/16 tubing length to about 10 feet. Result: no degassing in beer lines and better foam control coming out of the tap. Thanks for the advice!

Physics...it works every time!



-ssb