Corny's...

[Aleman]

Nothing to do with the diameter or length of your line. You need to understand the relationship between temp and pressure.

Uhhhhhhhhhhhhhh, not strictly true, the amount of carbonation is a function of temperature and pressure :thumb: . . but whether you get foam or not is dependant on you having a balanced dispensed system . . . . the pressure drop (due to resistance of the beer line) needs to be such that at the tap the 'pressure' is effectively 0 psi. Now this is possible to achieve by dropping the pressure in the keg to dispense and then increasing it back up afterwards, but this can create foaming issues on it's own with highly carbonated beers. If you have 25psi in the keg and your beer line has an effective resistance of say 2.5psi per foot you would need 10 feet to drop the pressure enough to serve without foaming . . . of course if you beer line only has a drop of 0.5 psi per foot you would need 5 times as much.

30psi at 7c is a VERY carbonated beer.

Oh Yes :thumb: and it's possible that even with a balanced system you won't be able to serve it without foaming, simply because of the fact that even the turbulence of flowing over an edge (between beer line and a JG fitting) can cause break out of CO2

 

[Stapsin]

In truth the beer is probably closer to 8 degrees C rather than 7 so based on the chart I have is an acceptable fizziness for a hefe.

In regards to the pressure/balanced dispense system, would you recommend dropping the serving pressure right down and see whether it eases the foaming issue?

Would you say that it is more likely that the beer in the corny is fizzy my issue is just that it is losing fizz/its becoming foam as it leaves?

 

[pittsy]

Nothing to do with the diameter or length of your line. You need to understand the relationship between temp and pressure.

30psi at 7c is a VERY carbonated beer. I carb and serve at 12psi and 7c without any problems through 3/8th line.

K

Got to disagree here , yes temp , yes psi but defo yes length of line plus diametre . The longer the line and the thinner the pipe creates more resistance also the serving height of the tap to the keg also affects things .
At 7c and at 30 psi ( around right for a hefe ) you need around 4ft of 3/16 line , you can do as above with 3/8 line plus adapters and heat up the end of the pipe it will just about slide on when heated and also use a jubilee clip to make sure it's tight .
If just using 3/8 line you'll need something like 15 ft or more ( so lots of beer wasting in pipe when not used ) .

 

[Aleman]

In regards to the pressure/balanced dispense system, would you recommend dropping the serving pressure right down and see whether it eases the foaming issue?

No, if anything it would exacerbate the issue, the beer is saturated with CO2 at equilibrium with the pressure in the keg. . . . . If you change the equilibrium (reduce the pressure) then there is more in the liquid than in the head space, so gas would travel from the liquid to the head space . . . i.e foam.

Would you say that it is more likely that the beer in the corny is fizzy my issue is just that it is losing fizz/its becoming foam as it leaves?

Yep, I had the same issue with a wheat beer, it was that saturated with CO2, that simply passing the junctions in the john guest connections would cause CO2 to break out (through turbulence). A decent length of 3/16 line reduced the problem significantly . . .as I could open the tap fully to allow the beer to flow at a sensible speed. A partially open tap created turbulence, which you need to avoid. . . . I would fill a couple of glasses or a jug and then things would settle down

 

[Stapsin]

Thanks for your help. I decided to give it a try of dropping the serving pressure down and also changed to using another tap. Whilst maybe the first 1/3 of the beer came out as foam it then became just beer. Whilst this was better it didn't seem to hold fizz for a very significant period of time. I have hooked it back up to the co2 and dialed the pressure up again and will leave it a few days. I will probably get some 3/16 line at some point also.

 

[kev]

Nothing to do with the diameter or length of your line. You need to understand the relationship between temp and pressure.

30psi at 7c is a VERY carbonated beer. I carb and serve at 12psi and 7c without any problems through 3/8th line.

K

Got to disagree here , yes temp , yes psi but defo yes length of line plus diametre . The longer the line and the thinner the pipe creates more resistance also the serving height of the tap to the keg also affects things .
At 7c and at 30 psi ( around right for a hefe ) you need around 4ft of 3/16 line , you can do as above with 3/8 line plus adapters and heat up the end of the pipe it will just about slide on when heated and also use a jubilee clip to make sure it's tight .
If just using 3/8 line you'll need something like 15 ft or more ( so lots of beer wasting in pipe when not used ) .

Sorry for the confusion Pittsy. Totally agree.

What I meant was you need to get an understanding of temp/pressure before changing lines, etc.

If the temps low and the pressures high there's no point mucking about with lines as the beers not conditioned correctly in the first place.

K

 

[pittsy]

Fair point , got ya :thumb: