CO2 comes out of solution in beer line

[slurms]

In my keezer, I've got one keg which after every pour, tiny bubbles of what I assume is CO2 form in the beer line between the keg and faucet. After a while, most of the line is gas and results in a foamy pour. However, the other keg I've got in there is perfectly fine. Keezer temperature averages around 38F and the CO2 is at 11psi. I've got one gas line coming in which splits to multiple, so they are all at the same pressure (and presumably the same temperature).

I know that if the pressure is too low for the temperature, the CO2 can come out of solution and form the gas bubble in the out-line, but with only one keg doing it, I figured it was something else. Is there anything else that can cause this for a single keg? I've tried tightening everything, keg lube (though on the liquid side, I'd expect beer to be dripping out instead of gas ingress).

Any suggestions/ideas as to what to do or what's going on?

 

[Broken Crow]

Apart from an oversized beer-line, (which I doubt you'd have).. Is there any chance you have a gap or something that would cause a major temperature differential in the lines path? Is there perhaps a very slow leak in the keg post on that line?

 

[Bobby_M]

A small leak around the liquid diptube's oring and the inside of the liquid out post will do this. Take that post off, check the oring. lube and reassemble.

 

[day_trippr]

Most likely cause is the beer was over-carbonated...

Cheers!

 

[mashpaddled]

My first step would be to check for a leak at the liquid post on that keg. If that fails to fix the problem then look at the gas flow to that keg.

Where in sequence is the keg with the foamy beer line on the gas distributor? If it's the last keg to get CO2 you may have an issue with losing pressure to it. If there isn't enough pressure to go around to all the kegs you can run into this problem as you draw beers from kegs closer to the tank you lose pressure in other kegs. If there is more line on the last keg that will amply that problem. Ideally you would have independent regulators on each line coming off the distributor so you can set the pressure a little higher at the tank and set the individual regulators lower to maintain even pressure on all kegs.

 

[slurms]

Thanks for the tips everyone. When this one kicks (which should be soon), I'll be checking the posts and the o-rings. Didn't notice any leaking, but doesn't hurt. As for a temperature differential along the line, nothing sticks out to me as to which would cause one. It's no different than any other keg in there.

Over-carbed is possible, though I've had a keg in the same spot on the gas line in the same keezer conditions and it was fine.

I've got evabarrier tubing coming into the keezer through the coller and then a straight line of it with multiple T's to split from. The keg in question is the first one on this line. The other keg in there is the last on the line. Thinking I might have one junction off the main line instead of multiple splits off of it, maybe that will help to keep the gas line lengths the same?

 

[Bobby_M]

The gas distribution doesn't have any effect. Note that when I mentioned leaking, I'm not talking about external to the keg. The headspace is filled with pressurized CO2 and the long draw diptube has to get into the liquid post without any CO2 leaking into that stream. There's a single oring between the keg and the top of the diptube that has to work properly or gas can get injected into the liquid path.

To rule that out, you can carefully lay the keg down on it's side with the liquid post at the lowest point. If the tube does not fill with Co2 in that position, the above is your issue.

 

[Saunassa]

Does it follow that particular keg? If you move it to a different line you can determine if gas and beer line related or the particular keg. Then you know what needs troubleshooting,

 

[ScrewyBrewer]

Replacing a beer post connector that looked perfectly fine did fix a similar issue to the one you mentioned. Once the new beer post connector snapped on, the leaking bubbles stopped.

 

[slurms]

Note that when I mentioned leaking, I'm not talking about external to the keg.

This makes much more sense, should have realized what you meant. I'm thinking the liquid diptube o-ring is most likely the culprit. After looking at a few from my other kegs, they look like they are starting to look a bit worn. Got new o-rings and will check for the next beer I brew.

Thanks for the help everyone. Much appreciated.

 

[spacey]

I had the exact same problem with a conelius keg a few years ago. The seal that exists between the pressurized gas headspace and the liquid beer (on either a cornelius keg or a commercial sanke keg) can create 50% foam in the glass and large air pockets in the beer line.

I just now drew a schematic of a corny keg on the left and a commercial/sanke keg on the right if that helps anyone.

Am I wrong on anything here?