Same Old Story - Frothy Beer. Why?

[mriksman]

Hi. New to keg systems. Have 2x 8L kegs. Sits in a fridge at around 6°c (43°f). Vertical distance from centre keg to tap is 870mm (2.854’). CO2 set to 9psi (have tried 12). Using 4mm (0.15748”) ID beer hose. Have 1.2m (3.937’) in the fridge, and then about 600mm (1.9685’) outside to the taps (wrapped in insulation). 1.8m (5.9055’) total.

Did the calcs on mikesolty, and got 1.14m (3.75’) required. Thought perhaps the too long a line caused a pressure drop causing froth. Trimmed the line back to the 3.75’. No change. Probably a little worse. Once froth settles, beer tastes flat.

I’m out of ideas.

 

[grampamark]

Longer beer lines increase pressure. Smaller inside diameter lines do, as well. The point of balancing a draft system is to provide enough back pressure so that the C02 stays in solution all the way to the glass. Your beer is foamy because the gas is coming out of solution with the beer between the keg and the faucet.

Your 43°F and 9 psi is about 2 volumes of C02. That’s in the range for darker beers. Your beer looks lighter; a more appropriate carb level might be 2.5 volumes. At 43° that would be around 12-13 psi. The rule of thumb is 1 psi per foot of beer line. So, you would probably benefit from longer, not shorter, lines. In your case, about 12 ft total.

I’ll attach a carbonation chart in case you haven’t consulted one.

 

[mriksman]

I have consulted one - on Mikesolty’s website with the calculator. Even with 43°f and 12psi, the 4mm ID beer line has a calculated length of 4.14’. I had more than this length before I trimmed it. I thought; if I have MORE than what is calculated, then I should trim the line. Keep in mind I am using 4mm (quite small); not the typical 5mm beer line.
I’m gonna put the psi back to 12psi (from my test of 9psi), and buy 5mm line and run 12’ and see if there is any difference. Hell, I might run 15’ (or more) and cut lengths off to see the difference.

 

[Stormcrow]

My 4mm line is 7 feet long at 10-12 psi and working well so far.

 

[grampamark]

Is your beer line PVC or EVA barrier tubing? Most EVA users report being able to use a shorter run than PVC. Even then, 4’ seems too short. And 4mm isn’t that much smaller than the more common 5mm, 3/16” size. You should be able to achieve a proper balance, all other things being equal.

Foamy pours can be caused by one, or more, of several factors. Improper line length and/or diameter, over carbonation, or a poor seal at the liquid out connection which allows C02 from the keg headspace to enter the outflow are the most common.

Judging from the tag on the keg this is a commercial beer which was, presumably, properly carbed when you got it. That should rule out over carbonation. That leaves line balance or a bad seal on the out post. The former is more common than the latter but, if all else fails, it won’t hurt to check the condition of the seal at the keg.

 

[bracconiere]

i'm curious how you're carbonating the kegs? set and forget, or do you get rough with them?

NVM, the video won't play for me...

udging from the tag on the keg this is a commercial beer which was, presumably, properly carbed when you got it. That should rule out over carbonation. That leaves line balance or a bad seal on the out post. The former is more common than the latter but, if all else fails, it won’t hurt to check the condition of the seal at the keg.

if that's correct.....

 

[McMullan]

I've got a couple of these mini keg heads and I had a similar problem with one. I'd double-check the barb fitting under the liquid post to make sure it doesn't have a hairline crack. Do you observe gas bubbles in the beer line from the disconnect when pouring?

 

[mriksman]

Thanks everyone for your posts.

I’ve got two 8L kegs. Both have the same problem. I’ve just put on 4m (13’), 4mm lines (which I thought would be excessive for the small ID). (Almost) SAME PROBLEM. But pours slower, so it is a little less frothy.
This line is far more flexible than the last. The last line was EVA, this new stuff is clear and has no labelling.

I take them to a shop and they hook it up and force feed in commercial beer. So no ‘getting rough’ with them. Just bring them home, hook them up, and wait a day

I would have thought overcarb would still leave a relatively carbed/bubbly beer once the froth settles? But it looks/feels pretty dead shortly after the pour.

The issue exists on both kegs, so if it was the keg head, surely one should be behaving correctly?

After a pour, little bubbles do appear in the line.

 

[mriksman]

The beer is coming out much slower now with these longer lines. The beer is clearly foamy as it exits the tap; the foaming isn’t being caused by high speed, so I don’t think it’s related to the length of the line.
Is it because the tower isn’t cooled? Is foaming ‘normal’ with a warm tower?

 

[camonick]

The beer is coming out much slower now with these longer lines. The beer is clearly foamy as it exits the tap; the foaming isn’t being caused by high speed, so I don’t think it’s related to the length of the line.
Is it because the tower isn’t cooled? Is foaming ‘normal’ with a warm tower?

If you pour a second glass immediately after the first, is the second pint as foamy? Warm lines and towers/taps can certainly have detrimental effects on dispensing. If a second pour is better after cooling all the hardware, that’s where you should focus your attention. Longer lines never hurt anything other than you have to wait a few extra seconds to fill a glass… no big deal in my opinion.

 

[mriksman]

Video with no tap. Half pint in 12 seconds. No foam. Still flat mouth-feel.

 

[mriksman]

Video with tap with auto-close spring removed. About the same speed, no froth, and same mouth-feel.

 

[mriksman]

Video with the auto-close spring installed. Frothy pour.

 

[mriksman]

So the auto-close spring seems to be causing me grief.
And I’m still getting a flat mouth-feel even though I’ve bumped up to 13psi.
So:
1. Why is this auto-close spring problematic? Do other people have them? Do they have issues?
2. Why does my beer still taste flat? I’m at 13psi? Surely it should be a carby, bubbly delight!?

 

[Dland]

On the flat beer at 13 PSI question; how long has it been at that pressure? It takes time to force carbinate, and if carbonated with primer, maybe it is under carbed.

One can put a lot of dispensing pressure on semi-flat beer resulting in extra foam while dispensing, and still have it flat.

You might consider running your beer fridge cooler and also confirm fridge temp. If it is 43F in fridge, it is going to be a few degrees warmer by the time it is dispensed, depending on ambient temp, temp of glassware, etc.

Problem could be from dispensing hardware too.

 

[mriksman]

Beer is commercial beer. Could it have gone flat when I sat it at 9psi for a few days? Seems unlikely. How long sitting at 13psi should it take to get fizzy?

 

[Dland]

If you look the handy chart in post# 2, 9 PSI at 43F will give you an undercarbed beer in most styles. You'd be at just a little over 2 volumes carbonation, while mid range for your standard beer will be around 3 vols.

How long it will take to carb up ?, that depends on how much head space there is in keg, temp of beer and pressure you force carb at.

 

[mriksman]

Spring was the wrong way!!!!!

I reversed it, and now I get a good pour. Still too slow, so I’ll cut my lines back until it’s closer to the ‘10s per pint’ target people suggest. I’m about half that speed.

Will leave the CO2 at 14psi and see if I can get a bit of carbonation bite to it.