Pouring Pure Head?

[David Sinclair]

Buttersd70, sorry i completely missed your first post but i'll try and answer some of those question.

It's not a newly carbonated keg. And the problem appears after about two weeks even when there is a lot of beer in the keg.

Converted fridge with two taps in the door. Has been balanced, the temp is stable 7-8C. It's about 2-3 days between good pour and bad pour(just sitting, not being used).

It doesn't clear up after the first pour - it tends to happen when i leave the gas off.

Oh and i'm using those quick disconnects on one keg and the clamp on disconnects on the other keg, using the same type of beer line.

I think thats everything but i guess when your talking variables there is always a million more things ....

But it does seem to be better with the lower pressure, only the first little bit pours head then its good, thanks for the help guys.

 

[buttersd70]

OK, now I know that you're not pouring through a miracle box or pouring at cellar temp....it's a combo of things, but mostly overcarbonation, as everyone else has said. (but I was holding off on that judgement....because it's temperature dependant, and some beer is best at 14C+). 145kpa at 7C will give 3volumes CO2, which is pretty damn gassy to start with.

Added to this is the complication of line length and balance. It gets harder to balance correctly as the carbonation gets higher, because the higher carbonation requires higher pressure, and the resulting longer line length involved causes a pressure drop over the length of the line, which can cause co2 to break from solution in the line itself, causing bubbles in the line. This can be checked, either visually, or by pouring a couple of beers in a row (enough to clear the line completely.) What will happen if this is the case, is the first part will immediately head. Then it will pour, then you will get another burp as the bubbles that had formed at the keg end go through the tap. This break out of co2 in the line may occur when the gas is on, but is much more likely to occur if the gas is off.

The third thing is warm taps, which will cause foaming, but this is the lesser of the problems. Half a glass poured through should cool the taps enough to pour OK on a fresh glass.

From your temps, I presume that it is ale, not lager, so 3vol CO2, even if balanced and pouring correctly is too much carb anyway, IMHO. So you might want to revisit your desired carbonation levels, and your balancing. The shortest line possible (whilst maintaining balance) is the best way to avoid pressure drop, so you might want to consider narrower line.

I had a similar issue when I replaced some beer line. I was mid keg when I did it, and I knew the carb was OK, because it had been carbonated with the 'let er sit' method, and the first 1/4 was OK. After the line was replaced with flexright 5mm, it started pouring heady....I swapped back to the original line, and it immediately poured OK. It turned out that the line was too long (even though it was done from the balancing chart), and pressure was dropping in the line, and I had to shorten it. Bugger.

Hope this helps, mate.

 

[David Sinclair]

Holy shite, sounds like you have been looking at my beer lines in person!

There are bubbles in them and it sound like the CO2 is breaking out in the lines.

I think you have hit the nail on the head - pressure drop in the lines.

I'm set the pressure at 100kpa and rebalance - now!

Do you need different beer line for the MFL quick dissconnects? because when i swap the barb connect to the keg that is pouring bad it pour fine, use the MFL and it pours head! Do i need a different size beer line for the MFL quick disconnects?

Cheers Dave.

 

[buttersd70]

Holy shite, sounds like you have been looking at my beer lines in person!

To quote a very old comedic character...."I'm piz-chick!" :lol: