Strange Foaming Problem

[Flipper79]

Hi all,

first let me appologize for not using the search function well enough to find the answer to my problem.

The foaming problem I have seems to be unique in that I haven't seen these symtoms discussed here.

I have set up a chest freezer with a beer font installed on the lid. The font is flooded with cold water circulating through the font continually typical temperatures for the air temp and font water are 4 and 13 respectively.

When I first set my font up I used the "balancing a draft system" article to determine the beer line length and psi and acheived good results. I was still getting exessive head, but I had put that down to the initial burst of fluid from opening the tap, and pouring off 20-30ml in 1 glass before pouring into my drinking glass without closing the tap fixed that problem.

My new problem is that over the last couple of weeks after pouring off 20-30mls and switching to my drinking glass the beer starts to pour fine, but after approx 1/2 a glass it starts to foam. I can see the beer change colour as it leaves the tap.

I'm at a loss.......please help

 

[bonj]

Mate, you got me. You seem to have everything sussed out, but that has me at a loss. Changing colour? strange. You're not pouring normal beer through a stout tap or something are you? Either that, or you're over carbonating... hard to tell really. You've got me stumped.

 

[muckey]

hmm, not really sure myself. Sounds like over carb but if the system has been balanced the CO2 reg should show that by being at a higher pressure ( assuming no non return valve in the line. Sounds like thats not the issue though from your post.

I know with my temprite, having the kegs at ambient can cause some PITA pouring issues if the ambient temp changes too much over the day ( the kegs are not in the sun ATM but they are ambient). However that should not be a problem as yours are in the chest freezer and if that wasn't cooling, then it would be a dead give-away also. So discount point 2.

In this case, the best suggestion I can make it to check for small leaks in the beer line and fittings. Thats the only thing I can think of that would give a pressure differential enough to pull CO2 out of the beer

Hope that helps. I for 1 will be interested to hear if you do find the cause.

 

[crundle]

Is the gas left on all the time, or do you turn it on when pouring only?

Think back as to what has changed since the problem began, and that is where the issue is likely to be. It might be something really small, but try to think back and eliminate each thing you can remember has changed.

Hope this helps a little.

 

[barfridge]

I'm assuming that the beer is getting lighter in colour. This means gas is coming out of solution in your lines, indicating too much of a pressure drop between keg and tap.

So either your lines are too long, or your head pressure not high enough.

 

[Flipper79]

To add a little bit more info,

I have 3 taps, tap 1 has beer line length of approx 1580mm, tap 2 and 3 both have approx 1130. All taps are approx 1.1m from the center of the kegs, and everything was set at 1 bar. I haven't noticed a foaming difference between tap 1 or 2 and 3.

Initially I had set the system up to pour at approx 3L co2/L beer.

Everything was working fine till the weather warmed up a bit and now I'm getting nearly all head, as barfridge assumed the beer gets lighter in colour, which doesn't clear after a couple of glasses poured continously. And yes the gas is left on continuosly in a "set and forget" type arrangment.

Does anybody have any suggestions? Shorter line length, higher pressure? While I wait I'm gonna cut 1 of the lines back to 1m just to try it.

 

[bonj]

That's starting to make sense now. It is clearing after a few glasses because it is cooling down the tap and shank/font. The heat from the tap and shank or font is what is causing your foam.

I re-read the OP. I'd say your flooded font water isn't cold enough, or there isn't enough of it to handle the cooling load.

 

[Flipper79]

So I've cut the line back on tap 3. and after 4-5 schooners poured (for sceintific purposes only), this is the result



Doesn't seem to be much of an improvement, maybe 10-20mm less head.

It would seem that I could pour 10 glasses and still not clear the beer........grrrrrrrr.......what do I do?

It seems that it gets worse as the keg gets emptier.

 

[barfridge]

Can you see any bubbles in your lines? I'm just trying to figure out of pressure loss in the lines is causing the bubbles, or if it's caused by being heated by the font.

It's times like these that I love my plastic taps, I never have problems in hotter weather

 

[Flipper79]

Hmmmm...............

I thought for sure I would have gotten a ribbing for either playstation or yamaha......

More seriously, I can remember looking with great interest at bubbles forming in the lines some weeks ago.....but I had put the initial burst of head down to those bubbles because at the time the second beer poured perfectly, where as now I can't get a decent pour at all weather its 1 glass or 3 or 10.

I can't see me resolving this issue in the next week or so as the only keg I have with sufficient age on it to drink is very nearly empty! Oh the sorrow!

I'm seriously considering cutting all my lines off and starting again, set everything for 2.8 Lco2/Lbeer and try again with the next batch of beer, take careful notes on carbonation and report back.

What do you guys reckon?

 

[bonj]

I find I get pours like that towards the end of the keg.... I can't figure it out either, but mine does settle down after the first pour. It just seems to be foamier at the end of the keg. My latest Bright Ale was really foamy recently. It blew a couple of days ago... I should have guessed it was getting low.

 

[bonj]

I was thinking along the lines of lower thermal mass and a greater chance of going out of balance due to temperature swings.

That sounds plausible to me. The internal temperature of my chest freezer does swing a bit with the fridgemate and the cooling lag (it drops another degree or so after the fridgemate switches it off). Thermal mass could definitely explain that.

 

[Darren]

What you are doing is the best way to over-carbonate a keg. Turn the gas off. Leaving it on will also result in an empty bottle in quick time (most HB set-ups leak a little bit of gas)

My method is to fill keg. Add gas at full throttle until hissing stops. Put keg in fridge. Leave 24 hours then, add gas at full throttle until hissing stops. Turn off gas. You are now ready to go. Pour as usual. Once the flow stops hit the keg with gas at full throttle for a few seconds until pour is as desired.

It really is incredibly simple (throw away your carbonation tables as they are making it more difficult than need be and do not address your exact systems needs)

cheers

darren

 

[muckey]

if the gas is left on over the entire life of the keg, it will overcarb and you'll probably get some pouring issues towards the end.

I try and carbonate at serving pressure for over a weel before I actually drink the keg ( connecting it for short periods when I am home, usally before I leave for work and the when I get home). Means the keg is slightly under cabed when it is tapped but after a couple of days its usually good.

Darren makes 1 other important point - turn the gas off when you arent drinking.

Serving beers without the gas on works for people who have their kegs in a fridge and is better with lower carbed beers than higher carb.
If like me, the kegs are at ambient, as soon as the pressure drops I'm pouring a glass of head.. By turning the gas off between sessions, the first glass is normally very heady but after that all is good for the session.

was discussing this thread with butters while doing a mash on the weekend and we reached the conclusion that the issues were likely line length (bubbles in the line causing the colour change) but seems there is more that just balance going on. I agree with an earlier post that the font may not be cold enough. I'm a little surprised because having the font on top of the freezer should mean the line stays cold enough. Only remedy I can see here is - drink faster to stop the tap warming up :lol:

 

[Flipper79]

I seem to have found a solution to my problem of the icecream head.

I beleive the main culprit was the temperature difference between the beer and the tap so I replaced my corny keg with

a small radiator I aquired for the right price $0.00
and put a fan on it from a discarded fridge $2.00
an inline aquarium pump $50.00
Miscalaneous fittings to get it all working $15.00
Grand total of about $67.00

So now the temperature difference between the air temperature in the chesty and the water temp coming out of the font is a meager 1-2deg and the foaming issue seems to be resolved. First beer has about 25mm of head (which I find perfectly acceptable) and all subsequent beers seem to get about 10-15mm head.
Will post pics when the bar opens at about 11am.

Thanks to all for the help trouble shooting this.

 

[reviled]

What you are doing is the best way to over-carbonate a keg. Turn the gas off. Leaving it on will also result in an empty bottle in quick time (most HB set-ups leak a little bit of gas)

My method is to fill keg. Add gas at full throttle until hissing stops. Put keg in fridge. Leave 24 hours then, add gas at full throttle until hissing stops. Turn off gas. You are now ready to go. Pour as usual. Once the flow stops hit the keg with gas at full throttle for a few seconds until pour is as desired.

It really is incredibly simple (throw away your carbonation tables as they are making it more difficult than need be and do not address your exact systems needs)

cheers

darren

What sort of KPA is "Full throttle"? :huh:

 

[Flipper79]

I don't know if anybody is interested but here are the photo's I promised



1st pour, and I didn't bother to collect the initial spurt in another glass



2nd pour about 20min later, still the original (now warm) glass



Shows the temperature difference between the air temp in the fridge and the temperature of the water exiting the font



My "u beaut super duper flooded font tank" AKA free radiator and $2 freezer fan from the tip.

I still need to neaten the piping and wiring up a bit but it all seems to be working well. Its amazing how much difference the radiator and fan has made.