Need help with beer carbonation

[Romex2121]

I’m using a 2.5 gallon (ball lock) corny keg with a single 5 pound Co2 bottle ... Problem seems to be keeping a constant level of carbonation in the beer , one day it’s perfect a couple days later it’s a little flat ..
Beer was 36 degrees and the regulator was set to 30 psi for 24 hrs or so , I did give keg a few good shakes in the 24 hr period , carb level seemed good beer was still at 36 degrees so I set regulator to 12 psi to keep a 2.5 ta 2.6 level of carbonation .
Couple days later beer was somewhat flatter than what it was ,
I’m wondering what I’m doing wrong and Why I’m I not able to keep a constant 2.5, 2.6 level of carbonation in beer ???

 

[Erik the Anglophile]

I don't keg (yet) but I have some experience with pressurised containers in general,it sounds like you might have a leak somewhere. I'd check all my fittings etc.

 

[palmtrees]

When you tested it the first time, was the keg still at 30 psi? Or did you drop it to serving pressure to push that sample? Sometimes when I pour at the high pressure, the sample will seem more carbonated than it would be at serving pressure.

 

[Romex2121]

I dropped it to serving pressure ,
maybe 5 psi to keep from foaming.
When that first glass seemed fine as far as carb level that’s when I turned the regulator down to 12 psi thinking that would keep a 2.5 ish carb level with beer temp at 36 degrees.
I’ve checked for leaks on the keg but found nothing
I’m kinda thinking while starting with
30 psi did carb the beer but turning it down to 12 psi after 24 hrs the initial carb level dissipated over the next few days and the 12 psi didn’t have enough time .

 

[day_trippr]

I think you found the cause of your drifting carbonation issue. If you are dialing the CO2 pressure down to dispense, the beer is going to lose carbonation to the ever-expanding head space. So then you recharge and the carbonation increases, then you dial down and the carbonation drops with every beer you pour.

Bottom line: set your regulator to "chart pressure"* and leave it alone until the keg kicks. If you have foam from dispensing it means there isn't enough line resistance to get the beer from keg under pressure to glass under no pressure without it bursting into foam. Longer lines - or at least, a higher resistance line solution - will address that. Consult the only line length calculator worth using to find the proper tubing diameter * length to treat your beer properly...

Cheers!

* Chart pressure is the product of temperature and desired carbonation level, and can be found in our favorite carbonation table.

 

[Gnomebrewer]

IME based on owning a total of two CO2 regulators over the years (i.e. not definitive), homebrew regulators seem to overstate pressure. 12PSI should be good for most cold beer, but is always undercarbonated in practice (or about right for English Ales) and pushes beer really slowly. My current reg is set at 16PSI (at 36F). I'm fairly sure 16PSI reading on my reg is actually about 12PSI.

 

[Romex2121]

If you are dialing the CO2 pressure down to dispense, the beer is going to lose carbonation to the ever-expanding head space. So then you recharge and the carbonation increases, then you dial down and the carbonation drops with every beer you pour.

That’s exactly what I’m having to do ,
My little 2.5 gallon keg came with 6’ of 3/16” line and a picnic tap so trying to dispense at 12 psi does cause bad foaming, as of now the cheap picnic tap fits my needs and I don’t see going to a fancy tap system.. should I double (maybe more) the length of 3/16” line and see if that helps ???,
having to dial down the regulator and purge keg of co2 to pour a glass is also waisting a lot of co2 .
If anyone has an idea of 3/16” line length that will get the foaming under control plz let me know…..

 

[Yooper]

That’s exactly what I’m having to do ,
My little 2.5 gallon keg came with 6’ of 3/16” line and a picnic tap so trying to dispense at 12 psi does cause bad foaming, as of now the cheap picnic tap fits my needs and I don’t see going to a fancy tap system.. should I double (maybe more) the length of 3/16” line and see if that helps ???,
having to dial down the regulator and purge keg of co2 to pour a glass is also waisting a lot of co2 .
If anyone has an idea of 3/16” line length that will get the foaming under control plz let me know…..

Yep- go with at least 1 foot of line for every psi on the regulator, and your foaming issues will go away!

Also, make sure you completely press open the tap handle when filling a glass. Sometimes people will open it only slightly, to slow it down, and it works like pinching a garden hose instead of slowing it down!