Having some foam issues with my kreezer, any ideas?

[CraigH78]

Ok so I just finished a kreezer and collar build. I started off with the kreezer and temp controller to make sure everything was working correctly. We had a party over Labor Day weekend so I put a 1/2 keg of Sam Adams in it, put my CO2 bottle and regulators in it, and a simple picnic tap so everything is inside the kreezer. I set my CO2 pressure to 12psi and started with a 20' length of 3/16 tubing on the tap side. After letting the keg settle for about 3 days I tapped it and enjoyed my first poor. It came out very slow so I cut the tubing down to 15', still a little slow but it poored so nicely that I just desided to leave it and fine tune it after the collar was completed. Labor Day party went off without a hitch, everyone loved it. The following weekend I decided to build the collar out of 2x6 with a 1x8 Oak outer face and 5 holes for Perlick faucets. My budget only allowed for the install of 2 faucets right now but I capped the other 3 holes with some inserts from the local hardware store. Everything came out great. I have not had time to polyurethane it yet so I am still using the picnic tap with everything inside.

Now to the issue at hand, it is now about 2 weeks since I added the collar and I am noticing some foaming issues. What once was a great poor is now 90% foam the first 22oz glass, 50% foam the second, and 30% the third. the beer is also very cloudy and I'm getting some strong wheat type flavors. My initial thought was we were just getting to the end of the keg and so I got a pitcher and started filling it. Didn't kick.. ok a round for everyone.. Lets try again.. nothing.. After about 5 pitchers it was still going strong so I gave it a rest. Over the past week, I've taken about 8 - 10 pint glasses and the keg has not kicked. (I know what your thinking, pickup the keg and see how heavy it is.. well a 16" diameter keg didn't fit will in a freezer with a 15 1/4" opening so we spread it with a bottle jack, dropped the keg in and released the jack. so it doesn't budge much lol ). Something strange I did notice though is that on the first poor of the day, the tap line is almost empty even though it is still closed and tapped. So some how that line is bleeding back to the keg. I thought I had perhaps ran out of CO2 but that is not the case, the tank gauge still reads over 500psi and the supply doesn't budge from 12psi.

So I'm puzzled as to what is causing the foaming issue. There are only 2 things that have changed, the level of the keg and the addition of the collar. I have the temp set to 40 degrees with a 3 degree hysteresis band so it has a range of 37 - 43. The tap line is in the kreezer so its not a temp issue there.. I have seen people put small fans in the kreezer to keep the temp evenly throughout, I do not have one, could that make that big of a deal? I also thought perhaps a pressure change within the keg due to there being less beer but shouldn't the CO2 balance that out? The beer is carbed well we I finally get a good poor, it doesn't seem to be over carbed to me but maybe that's because it foamed out the excess. Should I try turning the pressure down? I just dont want to have flat beer by doing that either.

What do you think? Here are some picture, bad ones, but pictures none the less.

 

[JuanMoore]

The first obvious issue is that your serving pressure doesn't matching the carbonation level. Sam Adams distributors suggest 38° at 14 psi, which means the beer is carbed to ~2.75 vol. To maintain that same carb level at 40° you'd need a serving pressure of 15 psi, not 12. As it sits at a lower pressure, the CO2 wants to come out of solution, and it builds up in the lines as pockets of CO2. Usually this issue only causes excessive foaming on the first one or maybe two pours, so there may be other contributing issues.

The solutions are to increase the serving pressure to 15 psi to match the carb level (which might also require a longer beer line), decreasing the temp to 35°, or degassing the keg until it reaches 2.47 vol (12 psi at 40°).