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Undercarbonated, can’t figure out why

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AlexKay

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I’ve got a CO2 tank with a regulator set to 30 psi. This backs a secondary regulator which can be adjusted from 0 to 30 psi (I say this because I think it indicates the gauge on the secondary is not badly off.). The secondary regulator is set to 20 psi. Temperature is around 40 F. My beer is only slightly carbonated. Certainly not 3+ volumes. It also comes out at a trickle (though granted, through 12 feet of 4 mm EVA.). Any idea from anyone what might be going on?
 
Can you provide us with all the minute details of your kegging and carbonation process. Be sure not to leave anything out, even if you don't think it is significant

Brew on :mug:
 
I should add that the other kegs in the keezer on other secondary regulators carbonate just fine. It’s just this position that stays flat.

SOP is to use a tube from the fermenter spigot right into the lid opening of a cleaned (PBW, StarSan) 3 gallon keg, oxygen ingress be damned. Then close up the keg, fill with CO2 at about 15 psi, then vent through the PRV, repeated 5 times or so. Final fill, and then it generally sits in my 50 F garage for a few days to a few weeks waiting for a keezer spot to open up. Carbonation in the keezer is set and forget at the serving pressure. For this spot in the keezer, that’s 20 psi. Gas lines are PVC, liquid lines are EVA, primary and secondary regulators are Taprite. 12 feet of EVA to dispense from this spot, through a stainless Intertap (regular, not flow control.)

I hope I got everything. Thanks in advance!

Edit: set and forget ranges from 1 week to months. Doesn’t seem to matter.
 
Last edited:
I should add that the other kegs in the keezer on other secondary regulators carbonate just fine. It’s just this position that stays flat.

SOP is to use a tube from the fermenter spigot right into the lid opening of a cleaned (PBW, StarSan) 3 gallon keg, oxygen ingress be damned. Then close up the keg, fill with CO2 at about 15 psi, then vent through the PRV, repeated 5 times or so. Final fill, and then it generally sits in my 50 F garage for a few days to a few weeks waiting for a keezer spot to open up. Carbonation in the keezer is set and forget at the serving pressure. For this spot in the keezer, that’s 20 psi. Gas lines are PVC, liquid lines are EVA, primary and secondary regulators are Taprite. 12 feet of EVA to dispense from this spot, through a stainless Intertap (regular, not flow control.)

I hope I got everything. Thanks in advance!

Edit: set and forget ranges from 1 week to months. Doesn’t seem to matter.
Nothing obviously suspicious about any of that.

Brew on :mug:
 
You said "It's only this position that stays flat". Do you have a manifold after the regulator and any keg on position "x" stays flat? Or do you have multiple regulators?

I would look at a blockage in the gas line or possibly a failed component.
 
If the kegs are going to sit in the garage for a few weeks, might be a good time to let them naturally carbonate. A 3 gallon keg would need about 2.5 oz of corn sugar.

When ready, you could hook the up the keg immediately and not have to wait for it to come up to the carbonation level of the other kegs. The natural carbonation would also help consume any stray Oxygen in the keg
 
ILet;s assume that you have a decent headspace and are not cramming 30 psi CO2 into 100 ml of overhead space in a full keg.. You still may need to hit it with a few gas fills to get a couple of volumes of gas in there. Also you want to force carbonate at the lowest temperature you can, 40F is on the high side but should work. Carbonate before you tap your keg so you know how much CO2 you add.

if your beer is only trickling out you have a regulation problem somewhere. The keg should be under 12-14 psi serving pressure. Use an empty keg and pressurize the system and then disconnect the keg and check the pressure it retains. You can use a spunding valve set to a high pressure to check.
 
:oops: I just swapped gas lines and the trickle increased to a reasonable stream. Swapped them back and it stayed reasonable. Maybe the gas disconnect wasn’t seated well?! Embarrassing if that’s the case. Will give it a few days to carb up (if it’s going to) and report back. :oops:
 
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