Foam- All of a Sudden

[NOLA26]

I have had my current keg in my kegerator for about two weeks. FYI- I changed the faucet to a Nukatap a couple of months ago and all was good. Other than the first second or two of the first pour of the day being foamy, everything was fine. I figured that was just the hotter beer in the tower. I have since added a tower cooling fan. The keg was pouring fine until a couple of days ago when the keg started pouring all foam. Its a 1/4 barrel of Miller Lite. I have about 10' - 15' of beer line in a coil that sits on top of the keg. A few days before the foam started pouring, when I open the faucet to pour, its like there were air pockets in the line that needed to be purged out. Once they were out beer was pouring slightly foamy at first but manageable. Now, its almost all foam. Temperature is normal and nothing else has changed in my system. I'm scratching my head trying to figure out what the problem might be. With the system going from pouring fine, to air pockets, to all foam in a matter of days with nothing changing in the kegerator, I'm having a hard time trouble shooting the problem. There is no liquid leaking anywhere and my CO2 tank is not empty, so don't think it could be a leak of some kind. I tried purging the pressure from the keg and regulator to see if it was over pressurized, but the beer still came out foamy, just slower. Any suggestions?

 

[Broken Crow]

Given that it's Miller, I'm assuming it's a sanke keg and coupler. My searches haven't found it, but maybe someone else will remember; There was a post a while back where a sanke user was having the same problem and in the end it turned out that the problem was with the coupler... I think it was a leaking gasket on the coupler. These do develop over time. Have you examined the gasket?

 

[NOLA26]

I have not taken the coupler off yet, but the small gasket on the coupler was changed about 3 kegs ago.

 

[NOLA26]

Took the coupler off and checked the gaskets on the coupler and the keg and they all looked fine. I applied some keg lube and reinstalled. Still all foam. I might clean the lines tomorrow just to see if that makes a difference.

 

[IslandLizard]

What is the pressure on your regulator?

 

[whattabrau]

There is no liquid leaking anywhere and my CO2 tank is not empty, so don't think it could be a leak of some kind. I tried purging the pressure from the keg and regulator to see if it was over pressurized, but the beer still came out foamy, just slower. Any suggestions?

If your tank is empty*ing* (all liquid CO2 has turned into gas but there is still gas left), the regulated pressure may increase as the tank pressure drops, and the regulated pressure increase may cause overcarbonation.

Or, the pressure might have been set too high all the time and it's been slowly overcarbonating.

Also, reducing CO2 pressure to under the equillibrium pressure will cause *more* foam due to increased breakout in the line, but yes, a slower pour. It will *not* instantly fix overcarbonated beer.

 

[NOLA26]

Pressure is 10psi.

 

[NOLA26]

Still having issues with a ton of foam. I just replaced the keg with a new keg of Miller Lite. I cleaned the lines and faucet. Still nothing but foam. I ordered a new keg coupler and installed it today, still foam. Does beer line go bad? I'm willing to try anything at this point. I'm not sure what else to check.

 

[IslandLizard]

How long is your beer line?
And what's its inner diameter? It should be printed on the line.

Is the beer in the keg cold? What temperature is the kegerator set at?

 

[camonick]

I’ve read before that Miller Lite is packaged with 2.7 volumes of CO2. OP doesn’t state what the temperature of the keg is, but to maintain that level of carbonation, you’d need to apply 14 psi at 38°. Your system would then need to be balanced for those parameters to achieve a proper pour.

Here is one of many carbonation charts to help understand the volumes at different pressures and temperatures.
https://www.kegerators.com/carbonation-table/

 

[IslandLizard]

It's indeed puzzling, as everything had worked fine for a (relatively) short time. Once the foaming problem started it hasn't gone away, and wasn't resolved when hooking up a new fresh keg.

The only things I don't see confirmed are:
a) The temp of the kegerator/keg/beer. Could it be higher than 34-36F?
b) The internal diameter of the serving line is not listed.

Mind, there were no apparent problems at first, it all worked fine for a relatively short time.

I'm highlighting (some of) the most important facts of the problematic system, as reported by the OP:

Pressure is 10psi.

I have about 10' - 15' of beer line in a coil that sits on top of the keg.

The keg was pouring fine until a couple of days ago when the keg started pouring all foam.

A few days before the foam started pouring, when I open the faucet to pour, its like there were air pockets in the line that needed to be purged out. Once they were out beer was pouring slightly foamy at first but manageable. Now, its almost all foam.

Temperature is normal and nothing else has changed in my system. I'm scratching my head trying to figure out what the problem might be. With the system going from pouring fine, to air pockets, to all foam in a matter of days with nothing changing in the kegerator, I'm having a hard time trouble shooting the problem.

 

[NOLA26]

Temp is 38 deg. I replaced the beer line with 10' of new 3/16 ID line. I'm still getting the air pocket in the line on the first pour and on other pours that are about 20 mins or so later. After about 12-16oz of beer being poured, the foam for the most part goes away and I can pour normally. I do have a tower cooler fan also. For the life of me I can not figure out why the air pockets are there or what is causing so much initial foam. I don't have a way to check the pressure in the keg itself, but I have been burping the keg to see if there was too much pressure, but I have to admit I am doing this without really knowing what I'm doing. To list the things I've done:

Replaced keg coupler
Replaced beer line
Cleaned faucet and lines
Replaced keg

 

[day_trippr]

For the life of me I can not figure out why the air pockets are there or what is causing so much initial foam.

Pockets typically form in idle lines when either the CO2 pressure applied to the keg is below that required to maintain the carbonation level extant, OR the temperature of the beer rises enough that the beer can't maintain the carbonation level and starts giving up gas. If you look at our favorite carbonation table you can see what happens if either temperature rises or pressure drops on how much dissolved CO2 the beer can sustain by the difference in Volumes of CO2.

The trick is figuring out which condition applies.

But one hint is the beer: Miller Lite is allegedly carbonated to 2.7 volumes - a bit higher than more ales - so I'm betting you've been dialing down the CO2 pressure below the level needed to prevent CO2 breakout. Try raising the pressure by 1 psi each day until you stop seeing pockets in the idle beer lines - or you hit the temperature/pressure combination for 2.7 volumes...

Cheers!

 

[day_trippr]

[edit: wrong "N" OP ]

 

[NOLA26]

Thank You Everyone!!!! I finally got it dialed back in again. Still waiting to see of the air pocket issue resolves itself but at least I can pour actual beer again and not get all foam. When I measured the keg temp with a laser surface thermometer, it was 50 deg. Last night I lowered the temp and made sure the pressure was at 12-14 psi. Poured a beer just now and after about a second of foam, poured perfectly. Now I need to reinstall my tower cooler and all should be perfect again. I cant thank yall enough for the help!!

 

[IslandLizard]

Thank You Everyone!!!! I finally got it dialed back in again.

I'm curious, what did you do that actually fixed it?