Air Pockets forming in Beer Out Lines?

Hi,

I'm using two corny kegs with picnic taps in the interim until i finish building the collar and etc... Yesterday i hooked up my Hefe keg and for some reason the Picnic Tap line has air pockets all throughout. Therefore, every glass of beer is guaranteed at least 3" of head. Does anyone know why my beer out line would have gas in it?

The first second of beer comes out like pure foam. Then it's a solid stream of beer. Putting the picnic tap down, within a couple of minutes i have a couple of gas pockets in the hose.

FYI, the kegerator is running at 45 degrees fahrenheit and i'm serving at 8-10 PSI.

How long is your tubing? If it's anything under 5 feet, you can turn the pressure down to around 5-6psi. As for the air pockets, you might have to use hose clamps on the tubing where it connects to the nipple. The hose could be sucking air in if it's not very tight. The other option could be that the beer line has some small holes in it and it's sucking air in, in this case you should replace the tubing.

With my kegerator, the temperature at the top was 6 degrees c warmer than at the bottom. This was causing me to have CO2 coming out of solution (at 'normal' serving pressure of around 12-14 psi) in the lines. A small circ fan fixed that problem.

Plus, it isn't air, it's CO2. Not a problem.

Line is balanced at 45F at 8psi with 3/16" dia line at 25" or 36" at 10psi. If your line is 1/4" dia, multiply the line length by 4.

If I had to guess, you have one of three problems (other than what other posters mentioned):
1. You are using 1/4" line and have less than 8 to 12 feet. At that diameter, the line length needs to be long to scrub off the pressure.
2. You have dips in the line. The line needs to run uphill, even just slightly, from the keg to the tap at all times - pouring or just sitting.
3. You had the beer at higher pressure and reduced it (CO2 will then come out of solution to equilize) or you had the beer at 10psi at a colder temperature than 45F, then brought it up to 45F (warmer beer holds less CO2 forcing it out of solution).

Bearcat Brewmeister said:

Line is balanced at 45F at 8psi with 3/16" dia line at 25" or 36" at 10psi. If your line is 1/4" dia, multiply the line length by 4.

If I had to guess, you have one of three problems (other than what other posters mentioned):
1. You are using 1/4" line and have less than 8 to 12 feet. At that diameter, the line length needs to be long to scrub off the pressure.
2. You have dips in the line. The line needs to run uphill, even just slightly, from the keg to the tap at all times - pouring or just sitting.
3. You had the beer at higher pressure and reduced it (CO2 will then come out of solution to equilize) or you had the beer at 10psi at a colder temperature than 45F, then brought it up to 45F (warmer beer holds less CO2 forcing it out of solution).

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That is probably it, #3. I was serving at 36-38 degrees and then my friends couldn't taste the difference between an Oktoberfest and a Hefeweizen! So i warmed it up to 45. I also increased pressure to 9 psi from 6-7 to account for the difference in CO2 absorption.

I had this problem not long ago. I think it's caused by a pressure differential between the beer and the CO2. (i.e. the psi of the beer is higher than the psi of the regulator, or vice versa). Give it a day for the temp and pressures to equlalize and everything will be fine.

jdoiv said:

I had this problem not long ago. I think it's caused by a pressure differential between the beer and the CO2. (i.e. the psi of the beer is higher than the psi of the regulator, or vice versa). Give it a day for the temp and pressures to equlalize and everything will be fine.

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Sorry to zombie this thread, but I’m having the exact same problem. Does the quoted post above hold true for others that have had this happen?
It seems most people misunderstood what the OPs problem was, since no amount of beer line would prevent an air pocket from forming. This is what’s happening to me. Same old 15’ beer line with a picnic tap served at 10psi but occasionally in some batches I get this “burp” where the first couple ounces will pour fine, then it goes SKLURP and blows a bunch of co2, then back to pouring beer, but the end result is glass full of foam and splatters all over the place.
I did notice the pressure in my keg seems to keep rising (prob have an infection somewhere) as the regulator will be reading 14 on the first pour of the evening when I’ve got it set to 10. I just don’t see how this could cause an air pocket. I’ve replaced o-rings on the keg post and put a new QD on the beer line. Same result.

The keg pressure always needs to be at the equilibrium pressure. This includes when pouring. You shouldn't ever be dropping pressure to pour. If you're pouring at 9PSI and 45F and you're pouring normal carb (~2.5 volume) beer, it doesn't matter how long your lines are. The pressure will rise because the beer is flattening, and as that happens CO2 comes out of solution. Both in your keg and in your lines. This forms gas pockets in the line, and lots of foam.

"Lower the pressure" is not a foam fix.

Again assuming 2.5 volumes, if you're keeping your keg and pouring at 45F, you need to be at 15 PSI. Then either longer lines or flow control faucets (or narrower lines, or some other method of back pressure).

Alright thanks. I need to figure out why my keg pressure keeps rising above my regulator set pressure, then. My chamber is set to 40F, but I’d guess raising it to 45F would make the foam worse without increasing beer line length or dropping the serving pressure, right?

How are you carbing? Simple answer in these cases is beer is overcarbed for the system.

Qhrumphf said:

How are you carbing? Simple answer in these cases is beer is overcarbed for the system.

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Natural carb at 12psi for a week before dropping to 10psi then it has been sitting lagering for several weeks now. The beer doesn’t taste overcarbonated, but like I said, the regulator will read up to 4psi higher than my set serving pressure after 24 hours of not having poured a beer

...which leads to the likely conclusion your beer is overcarbed even while your dispensing pressure is too low.
Fix the regulator problem. They should not drift repeatedly...

Cheers!

day_trippr said:

...which leads to the likely conclusion your beer is overcarbed even while your dispensing pressure is too low.
Fix the regulator problem. They should not drift repeatedly...

Cheers!

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So any idea what might be causing this drift? It’s a Pilsner fermented in my most recently purchased ferm vessel so I would think infection is unlikely, but who knows? You’d think the beer sitting at 10psi for so many weeks wouldn’t be overcarbed at this point. So should I raise the serving pressure to where it seems to be drifting , as a fix?

I wouldn't think that the regulator should climb in its own, but the keg pressure could be higher than it. But if you're carbonating and balanced at 12 PSI why are you dropping to 10 PSI (unless you're trying to speed it up based on an equilibrium pressure of 10 PSI)? If (assuming constant temp) you're fully carbed at 12 PSI, lowering to 10 will cause CO2 breakout (and an increase above 10 PSI) until it restabilizes (via continued bleeding off the pressure via either PRV or pouring) at the lower carb associated with 10 PSI

Amadeo38 said:

So any idea what might be causing this drift?[...]

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Could be something as simple as a tiny bit of debris sitting in the pin valve behind the diaphragm. Sometimes you can blow that out by closing the cylinder valve, removing any down-stream tubing, fully opening the output shutoff valve, dialing the regulator pressure knob up a few turns (which would be a crazy high setting), then with a good grip on the cylinder/regulator assembly, open the cylinder valve to cause a short high-volume blast all the way through to the output.

Do that a couple of times, then turn the pressure knob all the way down, put everything back where it belongs, then open the cylinder valve and dial up your desired pressure. See if it remains stable. If it doesn't, close the regulator output shut-off, and see if it climbs even without the keg attached...

Cheers!

Thanks @day_trippr and @Qhrumphf - last night I bumped up my regulator to match the PSI to which it seemed to be drifting and this evening I poured an air pocket-free beer!