Beer suddenly too foamy on tap

[user 336313]

So I brewed a wee heavy at the brewery. Fifty kegs. The first dozen or so tapped fine. But recently all I get is foam. Taste and aroma have not changed. What did change was the weather. It´s summer and hot in the pub. However, obviously the kegs are in a big fridge and kept cool. Nothing was changed pressure-wise. We keep it at 0,9 bar. Maybe the lines or system does suffer from the heat? Also, only the kegs that go on tap are put in the fridge. The bulk of them are in regular storage. Would the summer heat have an impact even if the beer is not infected with any unwanted yeasts or micro-organisms? Anybody any idea?

 

[JoeSpartaNJ]

Have you cleaned the lines?

Possible infection that took time to become known, even without off flavors?

Possbile over carb? Maybe try purging kegs before tapping?

 

[user 336313]

Have you cleaned the lines?

Possible infection that took time to become known, even without off flavors?

Possbile over carb? Maybe try purging kegs before tapping?

Lines cleaned: yes. Over carb can´t be it; same batch of beer, same settings at tap. Kegs are new and disposable. So yeah, maybe something is still alive in there, and kicking it in the heat...

 

[dan4665]

My guess is secondary fermentation in the stored kegs, test the keg psi and if needed spund around 20 psi or whatever works out on the pressure/temp curve going from storage to serving temperature, it may take a while. I keg in 5 gal cornies, store at cellar temp, and always get secondary fermentation and increased carbonation, I've seen it up to 60 psi.

 

[user 336313]

My guess is secondary fermentation in the stored kegs, test the keg psi and if needed spund around 20 psi or whatever works out on the pressure/temp curve going from storage to serving temperature, it may take a while. I keg in 5 gal cornies, store at cellar temp, and always get secondary fermentation and increased carbonation, I've seen it up to 60 psi.

Thanks for thinking about it. How does this work though? If I let a beer ferment out all the way in the fermenter, why does a secondary fermentation start in the keg? Wouldn´t that mean either an infection or a matter of beer that hasn´t fermented out? And I can´t imagine the latter...

 

[tracer bullet]

Do you have other beers to try? Maybe switch to a new beer in the same line, and see if it suddenly resolves itself (meaning - the beer was the problem), or stays present (meaning - the hardware is at fault). Now of course different beer will behave differently on its own but it might be a good start.

If the change was gradual it could imply a change tot he beer over time, i.e. wild yeast. If it was fairly sudden, I'd think it might again imply hardware. I'd consider looking all over the taps and such. Potentially even at the keg end. Broken o-ring or something dumb letting in air when the beer is drawn.

 

[user 336313]

Do you have other beers to try? Maybe switch to a new beer in the same line, and see if it suddenly resolves itself (meaning - the beer was the problem), or stays present (meaning - the hardware is at fault). Now of course different beer will behave differently on its own but it might be a good start.

If the change was gradual it could imply a change tot he beer over time, i.e. wild yeast. If it was fairly sudden, I'd think it might again imply hardware. I'd consider looking all over the taps and such. Potentially even at the keg end. Broken o-ring or something dumb letting in air when the beer is drawn.

Good point. But we did try rotating beers. It wasn´t the tap.

 

[dan4665]

Thanks for thinking about it. How does this work though? If I let a beer ferment out all the way in the fermenter, why does a secondary fermentation start in the keg? Wouldn´t that mean either an infection or a matter of beer that hasn´t fermented out? And I can´t imagine the latter...

I don't have an answer to that, but through experience, 100s of kegs, I get it all the time. I try to let my kegs condition at cellar temp, 62-70f depending on season, for about 4 weeks. And of course the secondary fermentation is more pronounced if I miss my target final gravity by a few points higher. The good part is you get great natural carbonation, also lowers the fg if necessary.

 

[jdauria]

How long are the lines from the keg fridge to the taps? Could it be cold beer hitting the hot tap lines causing the foaming? Are you talking like an underneath fridge with a tap tower on top? If so, do you have a fan blowing cold air from fridge up the tap tower? I know even in my own house, my kegs are in a fridge and because heat rises, the kegs are colder than the tap lines just a few feet above them and I usually get foamy pour on the first pour every time.

 

[Broken Crow]

I was just about to come in with the tower-cooling question, but @jdauria just hit it.. Can you post a pic of the system in question?
Just to share a similar issue I saw at a local bar: They had put in an extra countertop tower about 4' away from the refridgeration unit and just strung the beer line across under the counter...In winter, they had a space-heater under the counter and routinely kept a pitcher to pour foam into before serving each pint..Not a very good practice!..But that's what I saw and when I suggested they at least insulate the line and take away the heater, the improvement was enough that they eventually changed out to a trunk line and glycol chiller.

 

[odie]

I'm guessing keg-to-keg carbonation variation...

 

[jdauria]

I was just about to come in with the tower-cooling question, but @jdauria just hit it.. Can you post a pic of the system in question?
Just to share a similar issue I saw at a local bar: They had put in an extra countertop tower about 4' away from the refridgeration unit and just strung the beer line across under the counter...In winter, they had a space-heater under the counter and routinely kept a pitcher to pour foam into before serving each pint..Not a very good practice!..But that's what I saw and when I suggested they at least insulate the line and take away the heater, the improvement was enough that they eventually changed out to a trunk line and glycol chiller.

My local bar, which unfortunately does not have a great beer selection, kind of has a similar issue. Their kegs are in a self-contained outdoor walk-in, the lines run under their floor for about 50 to the bar and up to the taps. In the the winter, it's not much of an issue, but when it real hot in the summer, they start to have foaming issues as that outdoor walk-in fights to stay cold and then the lines in the floor warm up some also. And don't get me started on how the girls pour a pint by just putting the glass down on the drip tray and pour straight down into the glass.

 

[user 336313]

How long are the lines from the keg fridge to the taps? Could it be cold beer hitting the hot tap lines causing the foaming? Are you talking like an underneath fridge with a tap tower on top? If so, do you have a fan blowing cold air from fridge up the tap tower? I know even in my own house, my kegs are in a fridge and because heat rises, the kegs are colder than the tap lines just a few feet above them and I usually get foamy pour on the first pour every time.

Thank you. Will look int this!

 

[tracer bullet]

If you rotated the beers and it wasn't the tap, does that also imply it wasn't the lines and the rest as well? Are there other kegs in the same frig, or was the test perhaps with a warm keg or something, maybe a closer connection that didn't use the lines?

Just thinking along the line of "what it is / is not".

Do you have the means to put together a pressure gauge that could be attached to the keg's Gas / In side? Maybe the kegs in question have gone way up in pressure?