Air Pocket/ Foam

[NOLA26]

I just put a fresh keg in my kegerator. Before the keg was installed, I cleaned the lines and faucet, and replaced the O-rings on the coupler. I was having a foam issue that I solved by eliminating the quick connect from the coupler and doing a standard beer line. However, now I have seeing an air pocket in the line with initial foam.

The beer pours cold after about 5 seconds, which I figured was due to the warm temp of the faucet. However, after only about 5 mins, there is an air pocket in the line when I open the tap and the same initial foam for a few seconds. I installed a tower cooling fan which doesn't seem to do much, but my biggest question is where is the air pocket coming from? Again after a few seconds of runoff, the beer pours perfectly. There are no leaks anywhere and all the O-rings are new and lubed.

Not sure what to do to try and eliminate the air pocket other than to try and increase the CO2 pressure (currently at 10 psi).

Any advice is appreciated.

 

[mac_1103]

If this was a corny keg I would think that you're getting CO2 from the headspace into the beer line, either from a floating dip tube that's floating above the beer or through a small leak near the top of a standard dip tube. But since you said coupler I assume that we're talking about a Sanke, so maybe there's something wrong with the spear? Either way I doubt that increasing the pressure will help.

 

[NOLA26]

Yes it is a sanke keg. What is the "spear"?

 

[mac_1103]

The spear is what you actually attach the coupler to. Basically a long tube that draws the beer from the bottom of the keg. It also lets CO2 enter at the top of the keg.

 

[Climb]

Here are a couple of ideas:
1. Has the new keg been allowed to cool (stabilize temperature) in rhe kegerator?
2. Did you use a beer line calculator to determine your beer line length based on temperature, current keg pressure (not CO2 pressure unless you know things have equalized), rise/drop (middle of keg to shank) beer line ID, etc.? I wonder if removing the quick connect changed the balance on you.
3. Smaller ID beer line would help diminish the effect you are experiencing.
Good luck.

 

[Bobby_M]

Technically it's not "air" but no matter... The smaller of the two gaskets on the bottom of your coupler is what keeps CO2 and beer from mixing together. Even a tiny leak at that spot will spit CO2 into the outflowing beer. The telltale of that situation would be that you'd see bubbles streaming out of the coupler into the serving tube the entire time you're pouring.

The other reason bubbles form in the serving line is that CO2 is just coming out of solution and that happens for a couple reasons.

• The tubing is a little warmer than the beer below.
• The pressure going into the keg is lower than the established carbonation pressure. Use the "carbonation charts" to figure out what that pressure should be, but 9-12psi is about right for most fridge-cold beer.
• The lines are too short for the size of the inside diameter of the line. 10ft of 3/16" ID is about right and the number of home kegerators users that get this wrong is something like 99.99%

 

[NOLA26]

I should have mentioned that the keg is a commercial keg of Miller Lite. The rings on the coupler are new and lubed. The beer line was calculated when I first got the kegerator and I beleive I have around 10' of beer line. I'll check tonight if I see bubbles in the line when I pour a beer, but the beer pours perfectly after a few seconds.

 

[day_trippr]

Given macros really like carbonation as it covers up the lack of character, try increasing the CO2 pressure. The gas pockets may be occurring because the gas pressure is too low to keep the carbonation in the beer...

Cheers!

 

[Bobby_M]

It can also just be the temperature difference between the lower and upper area of the fridge. The tubing warms up and the CO2 cracks out. This is most likely the case if it's just the first rush of beer that's foamy. Ditch the first ounce and do the rest of the pour.