Avoiding foaming from corny tap

[Hogarth]

I'm not very fond of having great coils of beer line in my beer fridge, nor of depressurising and repressurising my cornies whenever I draw a pint. Just wondering if there any other ways of reducing the pressure at the tap to stop the foam? Some sort of counter-pressure mechanism, or expanding chamber, or something of that sort?

[Fil]

the 3/16" micro line is very effective at reducing pressure and a 5-6ft length is generally enough for most brews..

if your beers are generally served with less than 8psi a simple flow control tap or inline device may be all you need. i use 3 x flow control taps connected with 3/8" line thru a chiller to my kegs but if i try to serve anything above 6-8psi thru them they are impossible to set. at lower presures however they are a simply set and leave for the kegs duration..

[Kev888]

Thats similar to my experience too. At low pressures and if the beer and lines are kept both cold and consistent (temperature and pressure wise), you can go some way with flow control taps (and there are in-line alternatives too, I believe). But I wasn't quite so successful as Fill, sadly - I needed to keep below five or six PSI - which would have been perfect, except some of my cornies wouldn't seal reliably that low.

At higher pressure or if the beer lines are warm then the 3/16th stuff is the way to go for short runs IMO. The resistance causes a gradual drop in pressure as the beer flows towards the tap, helping to prevent foaming in the lines and reduce the abrupt pressure release as it leaves the tap.

One other thing I arrived at, was to both carbonate and serve at the same pressure (and temperature) . I know that some like to carbonate at a higher pressure than they dispense, but for me it tended to encourage foaming to dispense below equilibrium pressure.

[IPA]

I'm not very fond of having great coils of beer line in my beer fridge, nor of depressurising and repressurising my cornies whenever I draw a pint. Just wondering if there any other ways of reducing the pressure at the tap to stop the foam? Some sort of counter-pressure mechanism, or expanding chamber, or something of that sort?

There is only one reason that beer foams out of the tap and that is because it is over carbonated. Check you gravity before kegging. All of my beers including wheat beers arre served through 60 cm of 7 mm line and don't foam. Another test is to bottle a couple of pints and when it has conditioned open one. Does it pop or just make a slight hiss? If it pops it is over carbonated. Have you ever heard a bottle of commercial beer pop?

[Hogarth]

Thanks guys. Quick question: what's the deal with these 'flow control' taps. Do they work simply by restricting the size of the opening? Because pretty much any tap can do that, I'd have thought, if you don't open it fully. Or is there something else at work?

[Kev888]

The flow control taps I've had have a sort of shallow tapered cone inside thats moved in and out of a correspondingly shaped shell by means of a rotating collar, or on some models a lever. So the restriction is pre-set-able (letting you just flip the tap open fully as normal) and a little less abrupt than a simple narrow orifice.

But yes it isn't magic so there are some occasions where it is necessary to drop pressure more gradually via a long/narrow beer line. In my experience at least, it sounds like not everyone shares that. Though things are much more tolerant if the beer lines are kept cool and the temperature of the beer is kept stable, as it seems like you have.

[Fil]

the restriction is done with as little turbulance as possible, sharp edges within the flow can as i understand it form a point of foaming or nucleation? so straight cut beerline is best for inserting into JG fittings even the sharpest scissors will squeeze the tube out of shape before cutting and provide nucleation points all along the line for example..

and always open any tap fully too as it could also form a nucleation point..

[orlando]

Over carbonation is usually the problem. Like IPA I use very short lines with standard gauge beer line. I think the key to it is how you carbonate. If you force carb at high pressure over a long period it's worse. I now carbonate at 20 psi at circa 12c and check every 24 hours, typically 48 is enough. If I forget or it just goes further than I want flow control taps help but they still have to nearly shut off to fill a pint with little foam and that can take quite a while.

[Fil]

i agree the flow form a flow control tap can be a little slow, but i quite like popping the glass under the flipped tap and watching it just do its business..

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but good things are worth a wee wait

[f00b4r]

Over carbonation is usually the problem. Like IPA I use very short lines with standard gauge beer line. I think the key to it is how you carbonate. If you force carb at high pressure over a long period it's worse. I now carbonate at 20 psi at circa 12c and check every 24 hours, typically 48 is enough. If I forget or it just goes further than I want flow control taps help but they still have to nearly shut off to fill a pint with little foam and that can take quite a while.

What typical serving pressures and Line length do you use at that temperature?

[Jonnyconga]

I'm not very fond of having great coils of beer line in my beer fridge, nor of depressurising and repressurising my cornies whenever I draw a pint. Just wondering if there any other ways of reducing the pressure at the tap to stop the foam? Some sort of counter-pressure mechanism, or expanding chamber, or something of that sort?

There is only one reason that beer foams out of the tap and that is because it is over carbonated. Check you gravity before kegging. All of my beers including wheat beers arre served through 60 cm of 7 mm line and don't foam. Another test is to bottle a couple of pints and when it has conditioned open one. Does it pop or just make a slight hiss? If it pops it is over carbonated. Have you ever heard a bottle of commercial beer pop?

There are many reasons beers will foam part from over carbonation. Temp, width (bore) and length of lines to name 3.
A wheat beer carbed to 15 PSI and then served directly to a warm tap on a short line of 3/8 will foam everywhere. It's not over carbed, that's just how it's ment to be carbed (depending on the temp of beer).
I use flow control taps (chrome ones) almost exclusively and find they are good for use between different styles of beers needing different carbonation. I also have a normal tap with a fair bit of 3/16 and that works well too.

[orlando]

Over carbonation is usually the problem. Like IPA I use very short lines with standard gauge beer line. I think the key to it is how you carbonate. If you force carb at high pressure over a long period it's worse. I now carbonate at 20 psi at circa 12c and check every 24 hours, typically 48 is enough. If I forget or it just goes further than I want flow control taps help but they still have to nearly shut off to fill a pint with little foam and that can take quite a while.

What typical serving pressures and Line length do you use at that temperature?

As low as I can get away with, hard to be precise because the gauges are not finely graded. but typically circa 5 psi, the line length is not much more than 1/2 metre, usually less. The bonus with short lengths of standard line is a fine brush form Home Brew Builder means I can clean them very easily, although as they are so short and the line is cheap I often throw them and use new.

[f00b4r]

Cheers that's great info.

[Hogarth]

Ah, that's interesting about the flow control taps. Thanks. I do have a Dalex, in fact, so I'll try it with some 3/16 pipe and see.