Kegerator dispensing problems

[BS]

The two kegs that I brought to NCHF – amber and Baltic porter - poured perfectly there. Once I brought them home and put them in my kegerator, they poured perfectly as well, giving me a good 90% glass fill with a small and appropriate amount of head. The carbonation was appropriate. I was happy.

However, a week after I put them in my kegerator, I’m back to having the usual problem that I’ve been having. The amber pours with 95% head that takes forever to settle, and even that 5% is obviously flat. After the head settles, there is no carbonation at all, turning my awesome Levitation clone into something not very good. The Baltic porter pours with probably 85% head that takes forever to settle, and has some trace carbonation. I had hoped that putting the amber on 10 psi (which is my usual dispense pressure) would help carbonate it more, but instead now it’s just flat and lifeless. I had the same issue with the helles and mild I previously had on tap.

This is a repeat in a way of what drove me out of kegging in the 90s, when I had keg after keg of flat beer. Then, it was because I was dispensing at 3-4 psi in order to prevent the giant head like I’m getting now; now I know that pressure under 5 psi causes all the CO2 to come out of solution and makes the beer flat. However, I’m dispensing at 10 psi, so that shouldn’t be a problem for me now.

What should I do? I am frustrated and do not want to have to dump otherwise excellent beers because I can’t get them to pour properly out of the kegerator. I also do not want to have to go back to bottling a second time, which would make me the short bus-iest brewer in the BN Army.

Here is the relevant physical information about my setup:

2 Perlick taps (probably not the problem because they poured great right when I put the amber and the Baltic porter on)
38 degrees F
Two tube lengths – 7.25 feet for higher-carbonation beers, 4 feet for others; both tubes have 3/16” ID
The keg of amber has 10 psi on it (pushing it through the 7.25’ tube) and the keg of Baltic porter has 12 psi on it (pushing it through the 4’ tube)

Thanks for any help you can provide.

[BS]

For further background, the taps come out the front door of the kegerator fridge, which is a Sanyo. The lines are all completely within the kegerator. There is no tap tower; I don't have the skills to make one of those. Or, to pour beer out of a tap.

[DannyW]

Do you have a keg pressure tester? If not, buy or make one and see if the pressure in your kegs is what you think it is. A creeping regulator or bad valve could cause this move from good pours to bad.

Also put a thermometer in there, maybe even a remote probe type so you can keep an eye on the temperature and make sure it is what you think it is.

[manwithbeers]

Test the actual temperature of the beer from the second glass you pour. If your temperature is lower than you think the carbonation will rise. Use a good, calibrated thermometer.

Are you lines and Taps clean? Any restrictions or blockages will cause CO2 to break out in the lines. You could check to see if it is foaming in the lines of course.

How fast does the beer dispense? Oz per second? A 4.5 foot line seems fairly short to me. My lines are all twice as long. I think my shortest line is 8 feet. I dispense at 10 + PSI and ~37F.