Foam in beer lines

[Hayden123982]

Recently I have been running into foamy beer lines that are leading to foamy pours. Keg is in a full size fridge with taps on the door so beer lines are cold. Also beer line is 7 or so feet long. I’ve put many kegs through this tap and not had any issues until the last 2 kegs.

I can clearly see air space and foam in line that leads to a foamy pour.

So far I have swapped out the ball lock, replaced the tap, and cut 1 inch off of each side of the line and retightened my clamps. Different kegs both had foaming in line so I do not think this an issue with the post.

Hoping someone will have an idea for a fix!

 

[day_trippr]

Assuming it's not just an over-carbed keg...

Remove both disconnects, latch the PRV open, remove the long (Out) dip tube, and take a good look at the small O-ring under the flange. A nick in the right place will allow CO2 in the head space to inject into the beer stream under the Out post and you'll get foam right out of the keg...

Cheers!

 

[Brooothru]

Assuming it's not just an over-carbed keg...

Remove both disconnects, latch the PRV open, remove the long (Out) dip tube, and take a good look at the small O-ring under the flange. A nick in the right place will allow CO2 in the head space to inject into the beer stream under the Out post and you'll get foam right out of the keg...

Cheers!

Good point, and something worth checking.

Some other things to consider would be age of the beer lines (older lines may have some internal roughness, causing turbulence inside the beer line run while dispensing), possible buildup of beer stone (calcium oxalate, same stuff as kidney stones), height differential between the tap spout and the keg (technically the height from which the beer is being drawn, but this differential must be accounted for in calculating keg pressure). Of course, carbonation volumes and serving temperature are factors as well. Maybe the rear seals in the tap are worn and need replacing. There could be numerous items that can cause a foamy pour. I finally got tired of chasing the unicorn and bought two Perlick adjustable flow taps a few years back. Now all I have to do is get my keg pressurization, beer temperature and carbonation values in the right ball park and I can get a perfect pour almost every time with no waste and no frustration. Cheers!

Brooo Brother

 

[Hayden123982]

Unfortunately my foaming problem in the line still causes a pretty nasty foamy pour with my perlick flow control. It actually pours better with my old forward sealing tap.

I replaced all lines within this last year but I may try swapping out the line. Ill check the o ring first tonight, but I put a different keg on and it was having the same issue... but would love if that's the issue because its an easy fix.

 

[Robert65]

Unfortunately my foaming problem in the line still causes a pretty nasty foamy pour with my perlick flow control. It actually pours better with my old forward sealing tap.

I've used flow control faucets and found them to actually aggravate the problem. It seems that the reason is, that they introduce turbulence right at the point -- the faucet -- where there suddenly ceases to be any further restriction. I've found that a much better solution, if you need variable restriction in your system to accommodate differently carbonated beers, is to use a regular faucet and the flow control ball lock QD from Kegland, sold by William's. Putting the flow control at the keg instead of the end of the line gives you smooth flow the rest of the way.

 

[day_trippr]

Let's see if something falls out:

- How have you been carbonating these recent kegs, and what temperature and CO2 pressure are you using for dispensing? I had a suspicion you may be chasing an over-carbonation issue. Still do. Reference our favorite carbonation table to see how temperature and pressure work together in a myriad of combinations to arrive at specific levels of carbonation - expressed as volumes of CO2, where ~2.4-2.5 volumes is typical for most ales. You can use that table both to carbonate your beer and set up your dispensing system.

- What is the ID of your beer line? If it's 3/16", 7 feet is likely inadequate when used with a non-FC faucet, and will challenge the ability of an FC faucet to actually produce a foam-free pour. Reference the only beer line length calculator worth using for the science, or just use one foot of 3/16" ID line per PSI. Lines that are shorter than recommended will be the first to exhibit issues. An extra foot or more can provide more resistance to temperature swings.

- Do you have some kind of air-stirring fan running 24/7 inside the fridge to keep the temperature from bottom to top of the food compartment consistent? Stratification Happens, the beer is drawn from the bottom of the keg up the long dip tube and exits into tubing typically coiled atop the keg or routed high along the fridge wall to the faucet. It doesn't take much temperature differential to cause CO2 breakout - one can look back at that carb table to see how much less CO2 beer can hold for every degree rise in temperature - and bubbles beget bubbles begets foam...

Cheers!

 

[Brooothru]

Unfortunately my foaming problem in the line still causes a pretty nasty foamy pour with my perlick flow control. It actually pours better with my old forward sealing tap.

I replaced all lines within this last year but I may try swapping out the line. Ill check the o ring first tonight, but I put a different keg on and it was having the same issue... but would love if that's the issue because its an easy fix.

Try this with your Perlicks:

Close the flow control all the way off. Then open the tap full on. Slowly crack the flow control on the Perlick barely open and allow gas to vent until you get a trickle of beer flowing. Then slowly increase the flow rate. You may be able to control foaming that way.

Are you getting foam on just the first glass or on every subsequent glass as well? If just the first one, this technique might help.

Brooo Brother

 

[Hayden123982]

Thanks everyone for the responses!
The winner is....
Dip tube o ring! Was an easy fix and no longer getting foam in line for this beer. I will have to check the other keg out as well since I was having issues with that one. Could just be a coincidence that both kegs seemed to lose their seal on the dip tube.

I do think this beer does have a little bit more carb on it that I normally prefer as well and maybe played a roll in the foam issue as well. Probably a result from slightly too cold of a temp in the fridge. Its an old one so can be a little finicky so I turned that back down a little as well. Either way, no longer getting half pours of foam is nice! So thanks for the help

 

[day_trippr]

Those dip tube o-rings are vulnerable to tearing if installed dry, as they're subject to both compressive force and frictional force as the post is tightened. Always at least wet them first; even better, use a thin film of silicone grease (aka "keg lube") on them...

Cheers!