[Sea]

Been kegging for years, and long ago dialed in my preferred temp, pressures, line length etc.

I've got this commercial keg which pours about 3/4s foam no matter what you do. Keezer's at 38 deg, gas is at 12 PSI, and I've increased the 3/16" line from about 6 feet to about 11' in response to this problem. The longer line may have made the foaming worse! I know the keg isn't over pressurized because I have no check valves on the system

All my other kegs pour fine. The commercial keg I had on this tap right before this one poured fine (with the shorter line length!).

Any ideas?!? This is driving me crazy!

[yodalegomaster]

I went to the NHC presentation on serving draft beer, given by Ray Danials. The very surprising thing I learned is that beer foam is caused by pressure imbalance, That's either high or low. So what likely happened is that you went below the balance point and it will come back with an additional 1 or 2 psi of pressure. Yes, Add pressure and it will balance out a little bit. I know it doesn't sound right but that's what he said.

[Sea]

Originally Posted by yodalegomaster

I went to the NHC presentation on serving draft beer, given by Ray Danials. The very surprising thing I learned is that beer foam is caused by pressure imbalance, That's either high or low. So what likely happened is that you went below the balance point and it will come back with an additional 1 or 2 psi of pressure. Yes, Add pressure and it will balance out a little bit. I know it doesn't sound right but that's what he said.

You're right, it doesn't make sense, but i guess it's worth a try.

[pcollins]

It could be something as simple as the variability from the commercial brewery. I know they try to hit 2.4-2.6 vol of CO2 but they are sometimes off by a bit. Maybe you got a keg that was a bit high relative your system.

I would try purging the the keg through the release valve and let the pressure build again and try another pour. Also, what yodalegomaster said. Neither will be an "instant" fix but may balance out after a couple of pours.

Good luck.

[Sea]

Originally Posted by pcollins

It could be something as simple as the variability from the commercial brewery. I know they try to hit 2.4-2.6 vol of CO2 but they are sometimes off by a bit. Maybe you got a keg that was a bit high relative your system.

I would try purging the the keg through the release valve and let the pressure build again and try another pour. Also, what yodalegomaster said. Neither will be an "instant" fix but may balance out after a couple of pours.

Good luck.

I thought about this, but since I have no check valves on my system, an overpressurized keg would give me beer in my gas lines, wouldn't it?

And the more i think about too much pressure drop causing foam, the more confused I get. More pressure drop means lower flow rate, less agitation, how would this cause foam?

[lincoln]

Originally Posted by Sea

More pressure drop means lower flow rate, less agitation, how would this cause foam?

well yes but there need to be sufficient back pressure to keep the co2 in solution. as far as the beer is concerned you are starting the poor some where in the line. there is a balance point

link

[Sea]

Originally Posted by lincoln

well yes but there need to be sufficient back pressure to keep the co2 in solution. as far as the beer is concerned you are starting the poor some where in the line. there is a balance point

link

Interesting. So your saying that the CO2 can come out of solution quickly enough during the pour to cause foaming? I thought this takes a little time.

[lincoln]

its also being agitated by moving through the last of the tube and faucet. somewhere on the internet i came across a industry pdf explaining everything from an overview to way down into the minutia, i cant seem to find it now......

[bendavanza]

Commercial keg couplers have check valves built in, unless you removed it. The first thing I would do is bleed the keg pressure.

[Sea]

Originally Posted by bendavanza

Commercial keg couplers have check valves built in, unless you removed it. The first thing I would do is bleed the keg pressure.

That would make sense in this situation, except that I lost the little bugger when I last cleaned the coupler. Then I got beer in my gas line from this keg when I first connected this keg. I've since found and re-installed the check valve, but it almost seems like it made the foaming worse. Also I've been pouring off it for several months now, so I think the pressure would have dropped to my serving pressure by now.