Air pockets in beer lines and tons of foam

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Mjh1422

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This is my first go at kegging and so far it’s not going well. When I pour it’s all head and it spits air half way through then more foam, if I pour a second one right away, that one pours perfect. After I pour I can actually see little bubbles coming from the keg into the line after the pour and there is always an air pocket. I tried more pressure stepping it up all the way to 18psi, but that made things worse. I’ve gone as low as 10psi with no noticeable difference. I am running at 12psi with 5mm ID EVABarrier tubing at 8ft. Kegerator is set to 40F. All connections are Duotight with no leaks. Any ideas?
 

day_trippr

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Greetings, @Mjh1422! And welcome to HomeBrewTalk! :mug:

5mm ID EVABarrier is very close to 3/16", and that ID would typically require one foot of tubing per PSI of CO2 pressure. So you may be short on tubing length here.

But just to cover the bases, how did you carbonate this keg of beer? If you used some form of "burst" carbonation you may have ended up with an over-carbonated keg of beer, which would "stress test" the shorter than ideal tubing run...

Cheers!
 
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Mjh1422

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Hi @day_trippr thanks for the warm welcome and quick reply. I am a long time lurker short time member.

I force carbonated at 30psi for around 200 rocks of the keg laying on its side. Initially that was the perfect level, I then purged and set to 12psi. It is possible that when I was trying to make it better by increasing the pressure, I made it worse. I was thinking the co2 coming out of suspension was too low of a pressure. I also lowered the temperature to 34 for a couple of days trying to remedy the issue. Would an over carbonated beer in too short of a tube cause it to come out of suspension like that? This keg is at the very end, so for the next one I will try longer tubing. So I should aim for 12ft then?
 

day_trippr

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Well, I can see the potential for over-carbonation in the used process...But in any case the answer to the question would most likely be "Yes": overcarbonated beer will pick on any weakness in the dispensing system and too-short beer lines are the perfect target :) At 3/16" ID the "one foot of line per psi" rule of thumb is hard to beat, and 5mm is actually an appreciably larger bore than 3/16" (0.197" vs 0.185") so could use an extra bit of length...

Cheers!
 

doug293cz

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Are you using brand new kegs, or used? If used, did you replace all of the "O" rings? Damaged "O" rings on the beverage dip tube can cause CO2 to leak into the serving tubing. Bad "O" rings elsewhere can cause leaks, either CO2 or beer.

Brew on :mug:
 

day_trippr

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Well, you know I'd be the first to suggest that if I thought that was on-target.
But..."if I pour a second one right away, that one pours perfect." is non-indicative of infrastructure failure :)

"Air pockets" developing over time suggest the beer in the keg was carbonated to a level higher than the combination of temperature and pressure can support...

Cheers!
 

doug293cz

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Well, I can see the potential for over-carbonation in the used process...But in any case the answer to the question would most likely be "Yes": overcarbonated beer will pick on any weakness in the dispensing system and too-short beer lines are the perfect target :) At 3/16" ID the "one foot of line per psi" rule of thumb is hard to beat, and 5mm is actually an appreciably larger bore than 3/16" (0.197" vs 0.185") so could use an extra bit of length...

Cheers!
You would be well served to switch to 4mm ID for the beer lines, and save the 5mm for CO2. 4mm ID lines have more resistance per foot and you can get away with shorter lines, without having foaming issues.

Brew on :mug:
 

doug293cz

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Hi @day_trippr thanks for the warm welcome and quick reply. I am a long time lurker short time member.

I force carbonated at 30psi for around 200 rocks of the keg laying on its side. Initially that was the perfect level, I then purged and set to 12psi. It is possible that when I was trying to make it better by increasing the pressure, I made it worse. I was thinking the co2 coming out of suspension was too low of a pressure. I also lowered the temperature to 34 for a couple of days trying to remedy the issue. Would an over carbonated beer in too short of a tube cause it to come out of suspension like that? This keg is at the very end, so for the next one I will try longer tubing. So I should aim for 12ft then?
Agitating the keg at elevated pressure (more than the chart pressure for temperature and carb desired) is one of the best ways to over carbonate a keg. You are better off, if in a hurry, to chill the beer, put on 30 psi for 24 hrs without any agitation, and then release the excess pressure and set to chart pressure.

The "chart":

Carbonation Chart.png


Brew on :mug:
 

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When I pour it’s all head and it spits air half way through then more foam, if I pour a second one right away, that one pours perfect. After I pour I can actually see little bubbles coming from the keg into the line after the pour and there is always an air pocket.

It sounds straight-up over carbonated. Those bubbles are CO2 coming out. They collect and become your "air" pockets. After the first glass, if the second one comes quickly enough, they don't have a chance to reappear. but give it time of course and they are present again.

If you lower the pressure, you wont' get immediate results. It'll take a while for the beer to lose that carbonation. I'd unplug it altogether and pull the PRV on the top of the keg (pressure release valve) a few times a day for a few days. Eventually you'll get to where you want to be but it could take a while.
 

Beermeister32

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pull the PRV on the top of the keg (pressure release valve) a few times a day for a few days. Eventually you'll get to where you want to be but it could take a while.
Agree, likely overcarbed. Bleed off CO2 with the pressure release valve daily. Once you get it down, set your regulator to your intended pressure.

A lot of people carbonate to 10 psi, I’m actually preferring 9 psi. Also, use a flow control tap if you have one, they are great for adjusting out balance issues like this.
 
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