Excessive Foaming from Keg Faucet

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Imhoppy

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Just tapped a full 5-gallon keg of Dry Irish Stout. But there is excessive foaming from the Intertap faucet (with a self-closing spring installed). Pressure is set at 12 psi and temperature at 42F. Note the other keg is pressurized from the same CO2 source, pours fine, and has a self-closing spring installed on an Intertap faucet). After letting things settle down after drawing a sample glass, the next day there is some gas visible in the liquid line.

I have replaced the o-ring on the beer line outlet dip tube, thinking there might be gas leaking past a bad o-ring and into the liqiud line. But this has not solved the problem.

Never had this issue come up before, so I am at a loss as to why the foaming and gas bubbles appear in the liquid line. Maybe the dip tube has a pinhole leak above the liquid line? Seems unlikely, but I might try and replace the dip tube as my next course of action. I have used this keg numerous times without any problems before. Anyone have some other suggestions as to what the issue could be?

20210923_105422~2.jpg
 

Bobby_M

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The universal poppets (the spring specifically) that come in that keg have an occasional tendency to thread around the flange of the diptube. I mean it wedges itself between the diptube and the oring and messes with the seal. The simple test is to tilt the keg towards the liquid post so that that area is completely under beer and no gas. If the foaming stops, you're getting CO2 from the headspace into the liquid post.
 
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Imhoppy

Imhoppy

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Ok, so I thought awhile about the reply from @Bobby_M and I did some additional troubleshooting.

First, my kegs are A.E.B. (made in Italy). The posts for the gas-in and beer-out do not have "universal poppets", but the kind that has a three-pronged base. So this ruled out the theory of the spring threading around the dip tube, thus messing with the seal.

20210924_131849.jpg


Also, this is my 74th keg, and I have had trouble-free experiences with the previous 73 kegs. I have four of these A.E.B. kegs that I use in rotation. So, speaking from experience, this rules out any "beginner" type of issues.

The next step, after replacing the beer-out dip tube o-ring, was to change out the post assembly with another one from a spare keg in an attempt to rule out something faulty with the keg post itself. However, this still did not solve the excessive foaming and gas appearing in the liquid line.

Still frustrated, I then tried replacing the beer-out dip tube with another one from a spare keg, thinking that perhaps the dip tube had a pin-hole leak somewhere above the liquid line. Same results still having excessive foaming and gas in the liquid line. The crude sketch below shows the possible CO2 leakage paths.

Screenshot_20210924-153855_Samsung Notes.jpg


The only other thought I can think of is maybe the beer itself? I had it in the primary fermenter 28 days (which is my typical duration before kegging to give it extra time to clear) and then kegged it (O.G. = 1.041 and F.G. =1.015). It was stored at room temperature (~70F) for several weeks, while waiting for available chill space, before being placed in the kegerator. So just maybe the brew was still slowly fermenting and building up pressue and it self-carbonated above my serving conditions of 12 psi @ 42F, thus releasing gas into the line at the reduced pressure when serving. I don't know if this makes any sense, but what else could it be?
 

day_trippr

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The simplest answer is the keg is carbonated to a level above which the current environment (temperature & pressure) supports and thus the beer is outgassing to try to reach equilibrium.

Do you have a spunding rig? Or at least a low pressure gauge you could attach to that keg somehow? If you do, disconnect the gas line, burp the keg head space down to zero psi, then attach the gauge and see where the pressure ends up given the fullness of time...

Cheers!
 

Wables

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If you have another tap, switch over to it. I once had a bunch of crap built up in my tap that was causing a pressure drop, which was causing more foam.
 

jseyfert3

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The only other thought I can think of is maybe the beer itself? I had it in the primary fermenter 28 days (which is my typical duration before kegging to give it extra time to clear) and then kegged it (O.G. = 1.041 and F.G. =1.015). It was stored at room temperature (~70F) for several weeks, while waiting for available chill space, before being placed in the kegerator. So just maybe the brew was still slowly fermenting and building up pressue and it self-carbonated above my serving conditions of 12 psi @ 42F, thus releasing gas into the line at the reduced pressure when serving. I don't know if this makes any sense, but what else could it be?
Did you do the test suggested by @Bobby_M? That would differentiate between a headspace CO2 leak and an overcarbinated beer.
 
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Imhoppy

Imhoppy

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Did you do the test suggested by @Bobby_M? That would differentiate between a headspace CO2 leak and an overcarbinated beer.
Yes, definately an overcarbonated beer. I vented off the headspace, and a day or so later the overpressure condition continued. Did this a few times over the course of a couple weeks and I think it appears to be all settled down now. First time this had happened, so it was a big surprise. So the root cause must have been letting the keg sit at room temperature for a couple of months prior to chilling, even though it primary fermented for 28 days before kegging, with FG looking good at 1.015. But the yeast was still working away.

Usually when I keg, it goes right into chilling in the kegerator, or not long thereafter. I had fell behind in my drinking habits thus the delay in chilling. And the delay issue has also been corrected to my satisfaction!
 

odie

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The simplest answer is the keg is carbonated to a level above which the current environment (temperature & pressure) supports and thus the beer is outgassing to try to reach equilibrium.

Do you have a spunding rig? Or at least a low pressure gauge you could attach to that keg somehow? If you do, disconnect the gas line, burp the keg head space down to zero psi, then attach the gauge and see where the pressure ends up given the fullness of time...

Cheers!
My thoughts too..."just tapped" makes me wonder what the keg was carbed to. I've had some kegs pulled from cold storage to tap and found they are often higher psi than my serving psi so I have to spund them down.
 

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