Foamy Keg Beer

[pnorkle]

Hi Guys, hope someone might be able to give a little help here..
I keg my beer - I'm normally in no hurry to drink it, so I gas it up at around 100 psi for 3 days before I start drinking it.. this is normally just enough time to get it carbonated. So far, so good. Problem is, as I'm drinking the beer over the period of a few weeks, it starts to pour a lot of foam - before long, I end up with about an inch of beer versus the rest of the glass being foam. Generally I get foam when I first open the tap, but I find even if I discard the first part of it, I get the same result.

Any ideas? Thanks.

 

[paul]

How long is your beer line and what size is it?

Start off with 3 metres of 5mm ID beer line and work from there.

 

[pnorkle]

Yeah - I've got several metres of 5mm... now that I think about it, I never used to have this problem say, a year ago - it's only cropped up in the past year I'd say.. so maybe something's changed.

 

[fergi]

Yeah - I've got several metres of 5mm...

howdy pnorkle, easiest way to fix that problem is to go to articles at the top of the page and look for "KEG BALANCING"" i stuffed around for a few days when i set my keg system up and it was when i read this article and followed all the easy steps that i got it smack on, try it, its easy and works
cheers
fergi

 

[kabooby]

You might find that your fridge is colder than it used to be. This will allow more C02 into the beer. I have 3 meters of beer line, my fridge is set to 3C and I have the C02 at 85.

I would say that your beer is slowly over carbing being at 100

Kabooby

 

[newguy]

Every one of my kegs, when full, will pour a perfect pint. When the keg is nearly empty, I get the foaming issue you describe. Easy solution to this problem: disconnect the gas.

I don't know why this is, but disconnecting the gas solves it. You don't have to worry about it going flat, either.

 

[buttersd70]

Every one of my kegs, when full, will pour a perfect pint. When the keg is nearly empty, I get the foaming issue you describe. Easy solution to this problem: disconnect the gas.

I don't know why this is, but disconnecting the gas solves it. You don't have to worry about it going flat, either.

Lots of people find this to be the case...with my own beer, I find that (perhaps due to the lower pressure to begin with) lower carbonated (as in English) beer is less effected for some reason...it still happens, but not to the same degree.

I've never heard or read a definitive answer as to why this happens in the first place, though. I'm sure it's probably something simple, but would be interested to know the science behind it if anyone would care to enlighten me.

 

[reviled]

Lots of people find this to be the case...with my own beer, I find that (perhaps due to the lower pressure to begin with) lower carbonated (as in English) beer is less effected for some reason...it still happens, but not to the same degree.

I've never heard or read a definitive answer as to why this happens in the first place, though. I'm sure it's probably something simple, but would be interested to know the science behind it if anyone would care to enlighten me.

If butters doesnt know then who does? :huh:

 

[buttersd70]

If butters doesnt know then who does?

I have actually found one source that states that it is due to the relationship of the depth of the beer in the vessel to the surface area that is in contact with the CO2...ie co2 is more easily absorbed closest to the top, where the co2 is; so when the beer level is shallow, it more effectively absorbs co2 as a whole (because all of the beer is close to the co2). However, the same source also says that storing beer over 43F (6C) will make it spoil and oxidise. :lol: So I'm looking for a more, shall we say, reliable source.

 

[David Sinclair]

I have the exact same problem, the latest keg accidently froze, poured perfct now ALL foam. Tired rebalancing my system and it help, but i think this is a different issue than simply balance.

I frozen two kegs at different times and they have always poured foam when they thaw out - this might be a clue to someone smarter than myself.

But i'm inclined to think that as the amount of beer in the keg lowers, the remaining beer left gets colder (or freezes) and absorbs more co2?

Jeez i don't really know maybe someone has a temp control unit for their kegs or could rig up a unit directly to a keg so the beer always stays at the same temp no matter what the level - then report back with results

 

[cdbrown]

could depend on where you are measuring the temp within the freezer. I have the probe taped to about the middle of a keg, so for me a keg with liquid level below will get colder quicker when the freezer is on and will stay colder hence absorb more co2. If you have the probe on the bottom of the keg it may not experience the temp differential as much and then won't absorb more CO2 than you think it should.

 

[kabooby]

I have found this to be true. Always foams up towards the end of the keg. I believe that it is more to do with the beer being exposed to the C02 pressure for a long period of time and it keeps absorbing more C02.

It would be interesting to see if anyone has left a full keg in the fridge connected to C02 for the same amount of time that it takes for the other keg to get low and start foaming. Maybe we are thinking it is the keg being nearly empty and not the length of time under C02 that is causing the problem.

Anyway, I am testing this atm. I used to have my C02 set @ 95-100 kpa with the fridge set to 4-5C. Found the beers would be perfect for the first half of the keg and then they would start to foam up slightly getting worse towards the bottom. I have now set my C02 to 85 kpa and will leave it until these kegs get low. Time will tell

Kabooby

 

[reviled]

Time will tell

Damn time <_< Allways taking so long and stuff :lol:

 

[newguy]

It would be interesting to see if anyone has left a full keg in the fridge connected to C02 for the same amount of time that it takes for the other keg to get low and start foaming. Maybe we are thinking it is the keg being nearly empty and not the length of time under C02 that is causing the problem.

I can answer this. I leave my kegs connected to the gas. Connection time isn't the issue.

 

[David Sinclair]

I'm with newguy as well, disconnect the gas and the problem slowly disappears. Because the pressure in the keg is lowering with every pour and less co2 is absorbing into the beer which would be at a colder temp than a full keg. Does that make sense??

 

[buttersd70]

Why would a part keg be at a lower temp than a full one (other than one that has just gone into the fridge, obviously)? Wouldn't the temperature of the liquid achieve equilibrium, regardless of if it is 19L or 5L?

 

[newguy]

Why would a part keg be at a lower temp than a full one (other than one that has just gone into the fridge, obviously)? Wouldn't the temperature of the liquid achieve equilibrium, regardless of if it is 19L or 5L?

I think they may have been thinking about fridges without internal fans to stir the air. My keg fridge is actually a commercial single door unit like you'd find in a convenience store. It has a fan, so I'm quite sure that the beer at the bottom of the keg is the same temperature as that at the top.

I'm really curious as to the real reason why this happens but I can't figure it out myself. To me, CO2 absorption into the beer is a function of gas pressure and temperature. I can't see how headspace could factor into the equation, but it obviously does.

 

[pnorkle]

Well, there has been some interesting, and I would say quite valuable information here - thanks for all the input everybody.

It's interesting to see that I'm not the only person who has had/witnessed this problem. I think for starters, I might try disconnecting the gas line once it starts to foam up.. I think I'll also try reducing the pressure after the first 3 days to about 90 psi. I think that given the nature of the problem, this may be one of those ones that takes a little bit of experimenting to sort out..

 

[David Sinclair]

Why would a part keg be at a lower temp than a full one (other than one that has just gone into the fridge, obviously)? Wouldn't the temperature of the liquid achieve equilibrium, regardless of if it is 19L or 5L?

I'm not saying that the bottom of the kegs is cooler than the top. What i mean is that if you set the temp of the fridge at say 6C with two full kegs that when the beer is low the fridge is working just as hard as it did when they were full and because there is less beer and the fridge is working just as hard it gets colder. (At least i think that's what's happening with my fridge and it's not so accurate temp control)

Like when your fridge is jammed packed with food and you have to turn the temp right down to keep everything cold but then as your fridge empties you remaining food freezes.Something along those lines might be happening?

 

[crundle]

If you say that you are in no rush to drink the beer from the keg, then try gassing it up at a serving pressure of say 75-85kpa. It might take a week or so to get up to saturation point.

I don't have this problem of pouring foam at the end of a keg, but my kegerator has an internal fan that comes on when the compressor kicks in, so the temperature inside the kegerator is more even in my opinion. Before I installed the fan, I used to find that I would have foam come out at the end of the keg, and upon opening the keg to clean it, it contained ice in the bottom. Now this never happens, and the installation of the fan is the only thing I have changed.

In freezers, it seems that air stratifies, so it is colder at the bottom than it is at the top, fridges seem to suffer a bit less, maybe because the door gets opened more often.

Since installing the fan, my beers cool down quicker, and are gassed at serving pressure in under a week, where it used to take around 10 days prior to installation.

My 2c....