Exceedingly foamy keg pours

[fnffishcore]

I'm sure this topic has been covered over and over again, but I'm at a loss. I kegged a beer yesterday and had it sitting on 40psi overnight. I went to draw a sample today and it's like 99% foam. I tried the following tricks without any luck:

• Reduce regulator to serving PSI (12 PSI), turn off gas line, purge keg of CO2 and turn gas line back on.
• Try serving from one of my other taps, as well as a picnic tap, at both 40 PSI and 12 PSI.
• Tighten the worm drive clamp on the hose that connects to the flared barb on the liquid disconnect, tighten the swivel nut on the barb on the disconnect (both were already tight).
• Disconnect the gas line, shake the keg vigorously and purge gas a bunch of times before reconnecting gas to 12 PSI.
• Confirm keezer temp is cold (38-40° F) and circulation fan is working.

Regardless of these tricks, the keg still pours almost all foam. I've never had this happen before so I'm perplexed. It'll be 2 years since my lines were changed this February, but I don't think that's the issue as my other keg pours from the tap just fine. I tried connecting the tap to a different keg in my keezer and draw a pour and it came out fine. I also noticed that after drawing a pour from the problematic keg that bubbles start to form in the line just above the disconnect:

So I believe the problem lies with the keg, and probably the liquid post. I wrenched down on the post and it's not loose. Could it be the o-ring? And if so, is it safe to remove the post and replace the o-ring with the keg being full, after of course purging gas?

 

[day_trippr]

If there's a keg problem I would suspect the small O-ring under the long dip tube (the Out tube) is compromised, which allows high pressure CO2 from the head space to get into the beer flow under the Out (beer) post. It's a not uncommon problem.

You can replace that O-ring by disconnecting both the beer and gas keg connectors, and then latch the keg PRV open. Remove the Out post and pull the dip tube. Give the O-ring a critical eyeballing if you like, but I'd replace it out of hand. Make sure to lubricate that O-ring because if you install it dry there's the opportunity to cause micro-tears in the O-ring surface - which are more than enough to cause this problem.

Put everything back together, close the PRV, charge up the keg to "chart pressure" (reference our favorite carbonation table), and let everything chill back down before a test pour (warm beer and/or warm lines can cause distracting havoc).

Now, if that doesn't fix up your pours, consider the keg may be over-carbonated. That can also cause CO2 to break-out and has bitten probably everyone at one time or another, particularly if the keg wasn't carbonated using "chart pressure" alone. "Burst carbonation" has loads of over-carbonation risk...

Cheers!

 

[fnffishcore]

If there's a keg problem I would suspect the small O-ring under the long dip tube (the Out tube) is compromised, which allows high pressure CO2 from the head space to get into the beer flow under the Out (beer) post. It's a not uncommon problem.

You can replace that O-ring by disconnecting both the beer and gas keg connectors, and then latch the keg PRV open. Remove the Out post and pull the dip tube. Give the O-ring a critical eyeballing if you like, but I'd replace it out of hand. Make sure to lubricate that O-ring because if you install it dry there's the opportunity to cause micro-tears in the O-ring surface - which are more than enough to cause this problem.

Put everything back together, close the PRV, charge up the keg to "chart pressure" (reference our favorite carbonation table), and let everything chill back down before a test pour (warm beer and/or warm lines can cause distracting havoc).

Now, if that doesn't fix up your pours, consider the keg may be over-carbonated. That can also cause CO2 to break-out and has bitten probably everyone at one time or another, particularly if the keg wasn't carbonated using "chart pressure" alone. "Burst carbonation" has loads of over-carbonation risk...

Cheers!

Thanks for the quick reply! One thing I forgot to mention in my original post is that the beer itself is still low on carbonation, despite the foam. I've never had a beer over-carb in 24 hours at 40 PSI, but I definitely don't discount that it's a possibility. I do have a few sets of o-rings though so I'm gonna give that a shot and hope it is just the post and/or dip tube. I'm fairly certain I've never changed them so they're overdue.

 

[Vale71]

How are you assessing carbonation? If it's from a pour then of course it's going to be extremely low after almost all of the dissolved CO2 has left the beer turning it into foam. If you want to really assess the level of carbonation of the beer in the keg you need to disconnect the gas line, wait a couple of days at a minimum and then measure the headspace pressure with a manometer and then cross-reference temperature and pressure with a carbonation chart.

 

[fnffishcore]

How are you assessing carbonation? If it's from a pour then of course it's going to be extremely low after almost all of the dissolved CO2 has left the beer turning it into foam. If you want to really assess the level of carbonation of the beer in the keg you need to disconnect the gas line, wait a couple of days at a minimum and then measure the headspace pressure with a manometer and then cross-reference temperature and pressure with a carbonation chart.

Uhhhh..... my manometer is in the shop so I'm just going by intuition and past experience? Not the most definitive solution, but I'm brewing 5 gallon batches that I mostly drink myself. Doesn't have to be perfect.

 

[ehall]

you may try taking that tap apart, completely and see what shape its in. I've found in the past with chrome plated brass parts internally, the chrome coating comes off and causes foaming. if you have all SS taps, then maybe a good cleaning and even replace that hose on top of the other suggestions above.

 

[fnffishcore]

As embarrassed as I am to admit it, I think it may be overcarbed. I pulled the keg out and changed the o-ring on my dip tube, which was a little rough but not too bad. Even after shaking and purging the keg a few times, twisting the PRV valve to stay open and eventually removing the lid all together, a steady stream of foam rushed out the dip tube before reinstalling the liquid post. I guess there's a first time for everything! The only two things different about this batch and every other batch I've kegged is that this was my first kettle sour, and when I burst carbonated overnight I placed the gas on the liquid out post. It was cold crashed and has remained cold so I don't think it's some spontaneous fermentation or anything. I'm guessing there's something to carbing through the liquid post? Maybe lower the PSI next time.

you may try taking that tap apart, completely and see what shape its in. I've found in the past with chrome plated brass parts internally, the chrome coating comes off and causes foaming. if you have all SS taps, then maybe a good cleaning and even replace that hose on top of the other suggestions above.

I thought about trying that too. I have SS Perlicks but they haven't been cleaned since I changed my lines almost 2 years ago. I've been eyeballing them pretty new all black Stealth Bomber Nukataps, but a nice cleaning probably wouldn't hurt in the meantime.

 

[ehall]

uh, yea, you need to clean and prob change out lines...

 

[wsmith1625]

The first time I force carbed a keg, I accidentally put the gas on the liquid post and set it at #25 for 24 hrs. It worked great actually, but you run the risk of getting beer into your gas lines which is what happened on my second keg. To eliminate that risk, I now force carb on the gas post. After 24 hrs. at #25, it's mostly carbed and drinkable. Then I put it at serving pressure to get the rest of the way there which take a few days to a week.

 

[rsquared]

I've never had a beer over-carb in 24 hours at 40 PSI

when I burst carbonated overnight I placed the gas on the liquid out post.

So, what was your reason for changing carbonation methods? The point of carbonating through the liquid post is to bubble the CO2 through the beer and get it carbonated quicker, so if you're going to do that you need to significantly reduce the amount of time you are carbonating for.

 

[fnffishcore]

So, what was your reason for changing carbonation methods? The point of carbonating through the liquid post is to bubble the CO2 through the beer and get it carbonated quicker, so if you're going to do that you need to significantly reduce the amount of time you are carbonating for.

I've been meaning to try it and finally remembered to this time. I wanted to see how much quicker it was because when I carb through the gas post, it takes like a week or so to carb to my liking when starting at 40 PSI and gradually dropping over a couple days. With this beer, through the liquid out it was foamy in under 24 hours. Definitely was not expecting that.

 

[fnffishcore]

Wow... Just saw this on another thread and gave it a shot. Actually worked!

1. Hook CO2 to the beer-out (you'll be pushing it in backwards, down the spear), like for original carbonation.
2. Pull the pressure release.
3. Send low-pressure CO2 down the tube -- your goal here is just to make the beer bubble, to "shake" the over-carbonation out. (Go until it stops bubbling.)
4. Pressure release.
5. Low pressure bubbling; pressure release...
6. Repeat 3-4x.
7. Hook things up normally.
8. Test pour.

The last thing I thought to do was to put more CO2 down the liquid out, but doing so at a really low pressure evidently does that absorbed CO2 out.

 

[Beermeister32]

This one is really out there, but did you use gelatin finings in this keg before burst carbonating?

I've noticed a few times the presence of gelatin finings in the keg can add a bit to the keg carbing up. So then you burst carb the keg overnight you are adding to whatever CO2 saturation you have causing overcarbonation.

 

[fnffishcore]

This one is really out there, but did you use gelatin finings in this keg before burst carbonating?

I've noticed a few times the presence of gelatin finings in the keg can add a bit to the keg carbing up. So then you burst carb the keg overnight you are adding to whatever CO2 saturation you have causing overcarbonation.

Nope, no gelatin finings.

 

[Brian66]

Wow... Just saw this on another thread and gave it a shot. Actually worked!

1. Hook CO2 to the beer-out (you'll be pushing it in backwards, down the spear), like for original carbonation.
2. Pull the pressure release.
3. Send low-pressure CO2 down the tube -- your goal here is just to make the beer bubble, to "shake" the over-carbonation out. (Go until it stops bubbling.)
4. Pressure release.
5. Low pressure bubbling; pressure release...
6. Repeat 3-4x.
7. Hook things up normally.
8. Test pour.

The last thing I thought to do was to put more CO2 down the liquid out, but doing so at a really low pressure evidently does that absorbed CO2 out.

going through an over carbonation issue as well. Will try this tonight

 

[Brian66]

this solution for over carbonation worked for me!

 

[fnffishcore]

this solution for over carbonation worked for me!

Crazy, right!? I expected at best it would be as effective as just shaking the hell out of the keg and releasing gas, but it worked way better than that.

 

[Brian66]

yep I was shaking and releasing gas until I started getting foam out of the pressure release valve. This was much better!

 

[Brewer_Dad]

going through an over carbonation issue as well. Will try this tonight

What low pressure did you guys use?

 

[Brian66]

What low pressure did you guys use?

I just turned the CO2 on until I could just start to hear it flowing in. I think it was 3-4 PSI - but my memory is horrible these days.

 

[fnffishcore]

What low pressure did you guys use?

I just turned the CO2 on until I could just start to hear it flowing in. I think it was 3-4 PSI - but my memory is horrible these days.

I didn’t even pay attention to the pressure, I just turned the dial until I heard CO2 bubbling in. Once I did this trick and got the carbonation level to my liking, I set the regulator to my serving pressure, 10-12 PSI.