Troubleshoot this Corny Keg problem

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EdWort

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I have a good friend who has a keg that consistently produces foam. He brewed up and kegged a batch of Hefe for my Oktoberfest party and I carbed it with a few other kegs.

When I tapped it, I noticed that he gave me the foamy keg. The funny thing, the keg does not leak gas or beer, but when you dispense it, you can actually hear what sounds like air being introduced into the beer line as it dispenses. You can can see nothing but foam as it traverses the clear beer line to the faucet.

We've taken the post off and replaced the poppet and still the same. I'm wondering if anyone else ever came across this problem.

If we cannot solve it, I will wrap duct tape around it and mark "STOUTS ONLY" on it. :D
 
Pin hole leak perhaps, not enough to leak or show until you draw on it? I'd submerge it in a bathtub (remove beer) and pressurize to check for bubbles.
 
There are only two things that make any sense from the symptoms: One is a persistent infection, the other is a problem with the Out post. I'd swap the Out post with another keg and see if the problem moves...

Cheers!
 
Maybe a pin hole near the top of the out dip tube? If the hole is above the beer line maybe you get some kind of venturi action as beer goes up the dip tube. Swap the dip tube and see if the problem goes away.
 
Maybe a pin hole near the top of the out dip tube? If the hole is above the beer line maybe you get some kind of venturi action as beer goes up the dip tube. Swap the dip tube and see if the problem goes away.

Oooh. Brilliant! Never had a holed dip tube but that does sound like a solid possibility.

Cheers!
 
I'll agree that the dip tube hole is a possibility.

More likely the out post has a gouge in it that prevents a proper seal from being formed when the disconnect is put on.

More likely because the posts are out there exposed to the world, and ten thousand of them will get damaged for every one freak accident that punches a hole in a dip tube....

Could also be a bad disconnect, but since you say this only happens with one specific keg, I'd look at the post.
 
I'll second (or is it third?) the hole in the dip tube above the liquid level. Only thing I can imagine that would cause that to happen....
 
Maybe a pin hole near the top of the out dip tube? If the hole is above the beer line maybe you get some kind of venturi action as beer goes up the dip tube. Swap the dip tube and see if the problem goes away.

I'm thinking the same thing. It's like it's acting like a Stout restrict plate causing the foam.

The keg does not leak at all.

I'm going to swap out the dip tube tomorrow and see what happens.
 
I had a keg that always poured slow and just slightly foamy. I finally figured out that the diptube was the wrong style for the keg, and it barely left enough space under it for the beer to get through. I trimmed 1/16" off the diptube and the problem was solved. Doesn't sound like that's the issue here, but maybe food for thought.
 
I swapped out the gasket on the dip tube today. Same foam issue. You can actualy hear the foam being generated as it leaves the keg.

Swapped out the dip tube from a known good keg, same size with same ridges.

Works like a champ. Problem solved. BAD Dip Tube. It looks fine though.
 
I swapped out the gasket on the dip tube today. Same foam issue. You can actualy hear the foam being generated as it leaves the keg.

Swapped out the dip tube from a known good keg, same size with same ridges.

Works like a champ. Problem solved. BAD Dip Tube. It looks fine though.

Glad you got it sorted. Would be helpful to do a post-mortem on the cause, 'cuz otherwise it totally clouds the classic "Is my beer over carbed?" question ;)

Cheers!
 
Yeah, I'm trying to figure out this dip tube. They cost $17 to replace, but this one looks OK.

I'm going to run a brush though it and see what turns up.
 
I'm going with the "bad" dip tube was simply too long, causing the beer to squeeze through to enter the tube, thus causing turbulence and foaming.
 
Yeah, I'm trying to figure out this dip tube. They cost $17 to replace, but this one looks OK.

I'm going to run a brush though it and see what turns up.

I doubt the brush will turn up anything if the problem is a pin-hole leak. Your best bet would be to find the leak (plug one end of the tube and then submerge it while pressurizing the other) and then fix it with either solder or JB Weld (food safe version, of course).
 
Your best bet would be to find the leak (plug one end of the tube and then submerge it while pressurizing the other)

Brilliant idea Ace! Thanks!

Since I could hear it, I figured it would be then the end with flange & gasket.

I filled a pail of water and submerged that end with my finger sealing the top and blew air into the other end of the dip tube.

Sure enough, a tiny stream of bubble started flowing out of the tube about 3/4" from the end.

Looky what I found.

Damaged_Dip_Tube.jpg


This is a close up Macro shot, but without looking closely, it's very hard to find.

The case of the Perpetually Foamy Keg is now closed thanks to HBT Online Crowd Sourcing Collaboration. Thanks folks! :mug:
 
Yep, that'll do it.

You had a venturi that was forcefully sucking gas into the beer as it passed by.

I use a similar setup (intentionally) to aerate my wort when I siphon into the fermentor. Works great at that stage of the process, but definitely not something you want happening during the pour.
 
Brilliant idea Ace! Thanks!

Since I could hear it, I figured it would be then the end with flange & gasket.

I filled a pail of water and submerged that end with my finger sealing the top and blew air into the other end of the dip tube.

Sure enough, a tiny stream of bubble started flowing out of the tube about 3/4" from the end.

Looky what I found.

Damaged_Dip_Tube.jpg


This is a close up Macro shot, but without looking closely, it's very hard to find.

The case of the Perpetually Foamy Keg is now closed thanks to HBT Online Crowd Sourcing Collaboration. Thanks folks! :mug:

That should silver-solder right up. Perfect for a little capillary action!

M_C
 
Actually, given that the head space is pressurized with CO2, there's no need to complicate the issue with "venturi" effects...

Cheers!

Um... The beer was also pressurized to the same amount.

Would have flown by the hole just fine without sucking in any gas at all had there not been a venturi effect going on. Obviously the headspace wasn't pressurized enough to violate the laws of physics....

Cheers!
 
Um... The beer was also pressurized to the same amount.

Would have flown by the hole just fine without sucking in any gas at all had there not been a venturi effect going on. Obviously the headspace wasn't pressurized enough to violate the laws of physics....

Cheers!

Turbulence would have done it, too.

M_C
 
Um... The beer was also pressurized to the same amount.

Would have flown by the hole just fine without sucking in any gas at all had there not been a venturi effect going on. Obviously the headspace wasn't pressurized enough to violate the laws of physics....

I think fluid dynamics would prove that wrong, as given equal access to the hole gas under the same pressure as the beer would find it easier to pass through the hole...

Cheers!
 
Before pouring, the pressure in the headspace and the pressure in the dip tube are equal. But when starting a pour, wouldn't the dynamic fluid pressure within the tube (i.e., at the hole) be less than the static pressure within the headspace? Could that be enough to cause the CO2 to bubble into the dip tube and cause foaming?
 
Before pouring, the pressure in the headspace and the pressure in the dip tube are equal. But when starting a pour, wouldn't the dynamic fluid pressure within the tube (i.e., at the hole) be less than the static pressure within the headspace? Could that be enough to cause the CO2 to bubble into the dip tube and cause foaming?

That's where I was going. Could be wrong about it, but beer line pressure has to be lower than the head space, otherwise it wouldn't leave the keg ;)

Cheers!
 
Could you imagine if you were a kegging noob? W/O your experience I'd say EAC would have been uttered in record time.....

Glad you found the problem. :mug:
 
This is what I love about homebrewtalk - even mysteries can be solved with enough heads speculating....

Rich
 
This is what I love about homebrewtalk - even mysteries can be solved with enough heads speculating....

Yep, we all share a common hobby of homebrew, yet the experience and expertise in other areas is diverse and deep with this community.
 
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