Balancing keg system with corny keg/picnic tap

[BrettV]

So I've perused the boards, and googled the subject but I'm left with more questions than answers. I'm carbonating a pale ale in a corny keg right now. This is the set-up.

5-gallon Cornelius keg
4' of 3/16" beverage tube connected to plastic picnic tap
2.5 lb CO2 cannister

My fridge is 39 degrees. To get 2.5 volumes, it should be set to 12 PSI. Now, I've had it hooked up for 8 days, and I realized today I had it a little higher than anticipated (more like 16 PSI) so I bled it and reduced it to 12. I'm sure I probably need a longer hose, but every flipping pre-fab kegging kit always comes with a 4' hose (which kind of baffles me, because I've never seen anyone recommend less than 6-8 feet.) My beer is just ROCKETING out of the tap right now, and although it's been carbing for 8 days the beer comes out mostly flat with too much foam.

Math has never been my strong suit. With the specs I just provided, can someone "explain it to me like I'm 5?" For quick reference, here are my numbers again

5 gallon Cornelius keg
4' 3/16" beverage tubing connected to plastic picnic tap
12 PSI
39 degrees F

Help me balance my system?

 

[tjpfeister]

Extend that line to 12 feet and thank me later

 

[JuanMoore]

What he said^

To answer some of your questions, the reason kits are sold with short lines is that sellers assume everyone wants ice cold beer. The warmer the serving temp or more highly carbed the beer, the slower and gentler the pour needs to be to prevent foaming. Since line resistance decreases exponentially as flow rate decreases, you need to double or triple the line length to get it to slow down just a little. An alternative to longer lines is lowering your serving temp (and reducing the serving pressure correspondingly). I hate that people use terms like "balancing" when describing how long the lines need to be. This creates a misconception that there's some magic length, and any other length won't be right. The only negative side effect of super long lines is an ever so slightly slower pour. If you can wait an extra 2 seconds to pour your beer, it's likely worth being able to serve your beer at a wide variety of serving temps and carb levels. A decent rule of thumb for beers up to 40° and 2.6 vol is one foot of standard beer line per psi of serving pressure, or about 1.5 feet for smoother walled barrier type beer line.

Lastly, the reason your beer seems flat is that you're losing most of the carbonation in the form of foam during the violent pour. You need to try pouring it with a long enough line before you'll be able to tell if it's carbed yet or not. With 8 days on the gas, most of it at a slightly elevated pressure, your carb level is probably pretty good by now.

 

[Bamsdealer]

Till you get the longer lines try this. Carb the beer to your liking, cut the gas to the keg then bleed excess pressure in the keg. Set your pressure to 4 psi and pour

 

[JuanMoore]

Till you get the longer lines try this. Carb the beer to your liking, cut the gas to the keg then bleed excess pressure in the keg. Set your pressure to 4 psi and pour

And then return the pressure to 12 psi and keep it there between drinking sessions.

 

[BrettV]

Thanks, everyone! I'll probably scope out my LHBS for a longer hose. This particular keg is going to be served at a hotel party the last weekend of January, and likely won't last more than a night or 2, anyway, so even if I had to drop the pressure to 4 PSI it probably would be OK for that short period of time.

 

[Bamsdealer]

Thanks, everyone! I'll probably scope out my LHBS for a longer hose. This particular keg is going to be served at a hotel party the last weekend of January, and likely won't last more than a night or 2, anyway, so even if I had to drop the pressure to 4 PSI it probably would be OK for that short period of time.

Yep. Just make sure your beer is below the gas in dip tube or the pressure difference can force beer into the regulator. As noted above, if you leave the pressure on the regulator lower than what the beer was carbed to it can degas. This will take a while though.

 

[maffew222]

Also, don't discount the cleanliness of the line/input/etc. if there's a piece of hop material or something in there, you're going to get foaming no matter what the serving pressure.

 

[DrunkleJon]

I agree with the above. Either lengthen the serving lines (you can buy beer line by the foot then transfer the connectors from your already owned short lines to the new tubing), or drop pressure in the keg and dispense through the 4' lines.

And as for balancing there kinda is a magic number, though it is between 4 factors not just the line length. You have Carb level, serving pressure, Line resistance and Temperature that need to be balanced to each other. Its just that tubing tends to be cheap and it is far easier to throw an extra few extra feet of length on the serving lines than playing with serving pressure and carbonation level