CO2 in Beer Lines

So, i just got done building my keezer. I have perlick 525s and I keep getting a lot of foam. My temp is about 38 degrees, and I originally tried dispensing at 12lbs. When this resulted in foam, i dropped it down to 8lbs but i still have a lot of foam. An inspection of the beer lines show a lot of CO2 sitting in the line. I checked my fittings and I’m very confident that they are not letting in any air.

So my question is, what am i missing or doing wrong??? Could this just be CO2 coming up from the keg? Should I just disconnect my beer line whenever i’m not drinking?

Any advise is greatly appreciated.

You shouldn’t have to disconnect your lines. How long are they and what diameter?

I ended up with 7.5’ x 3/16 lines ( 30’ roll split between four taps) carbed and served at 12 psi. Nice head, about 1/2-3/4".

I started with short lines and lengthened to about 5’. I serve at 8-10 psi and have good luck. Also, I use 1/4" lines.

Even though you dropped the pressure, the beer is still carbonated at 12psi’s. It will take several pours for the CO2 to equalize.

You could disconnect the gas line. Then pour beer, 1-2 a day, until it gets slow. Then put the gas back on.

I have five foot long lines of 3/16. I’m pretty sure that I had pulled the gas release to drop the keg pressure. I guess i’ll have to dbl check that one to be sure, but i’m pretty sure that i did.

Pulling the PRV only dumps the CO2 in the head space. Just like opening a bottle, the gas leaves the head space but it is still in solution.

Similar to opening a 2l bottle of soda. If you open and close it every day, it will take about a week to become flat.

If you open it and pour a glass each day then close it, it will be flat in 3 days.

I honestly don’t know how long my lines are. Whatever length was attached to my tower (4-5ft?). But, once my beer is carbed, I have to turn the pressure down to about 4-5psi to serve. Anything approaching 10psi and I get too much head (never thought I’d say that :o )

I had problems with CO2 in the serving line of one of my kegs. Caused lots of foam. The problem with that keg was that CO2 from the headspace was getting around the diptube o-ring and into the line when serving. The fix was lube and an extra o-ring. This keg has worked fine ever since. Not saying that’s your problem, but worth a try.

I’ve been having the same problems with two of my lines. I have 10’ of 3/16" on 4 taps, and 8’ of 3/16" on two others. One of the 10’ and one of the 8’ get lots of gas in the lines. I may try the keg lube, and see if it’s a problem with the poppet o-ring as mentioned above.

If this is your first time at draught beer are you opening the tap fully? If you partially open it you can create foam.


Just to clarify: He’s talking the dip tube o-ring, where it meets the keg body, not the poppet o-ring.


[quote=“mbg”]If this is your first time at draught beer are you opening the tap fully? If you partially open it you can create foam.

Nope, not the first time with with kegged beer. I noticed this happening more after i built my keezer versus when i was using my picnic taps.

I’m struggling to find a post with a link to what I’m about to describe… there are stories of it working wonders to “fix” overcarbed beer.

Put your gas line on the liquid post and bubble gas through the liquid at the pressure you want the beer to be at. Apparently it forces the beer to reach equilibrium quickly because you’re providing a way for dissolved CO2 to come out of solution by “joining” with the larger bubbles.

I haven’t tried it but I’ve read plenty of stories of it working. I’m looking and if I find it, I’ll post the link about it.

Edit: found it: - follow his own tip… skip ahead to about 6:55.

again, never tried it, but heard it works.

I’m starting to think that this may be the problem with the keg. I get about six inches worth of co2 in the line. That is way more than i would expect to come out of the beer in the line. I just don’t know if I should try fixing it now or just living with it.

Just pull the gas line, then pull the release to let the pressure off the keg. Then be “clean” about things and remove the post on the serving line, take the dip tube out, add another o-ring and some lube, tighten it back down, hook 'er back up and start serving. The first pint will still have excess foam from the CO2 in the line, but you should know pretty soon if that was your problem. The whole process should take less than 5 minute. The keg I had with this problem still sports 2 o-rings on the serving post and works like a champ.

I did this and I did see an improvement but the issue isn’t completely gone. I did notice that the dip tube collar was a bit misshaped. I wonder what the best way is to fix the post so that it is no longer a problem…maybe gently shaping it with some needle nosed pliers will work.

FWIW my other keg is pouring beautifully!