Do you "tweak" the regulator during carbonation?

Hi guys,

I'm in the middle of my first effort at carbonating a beer with a CO2 tank and corny keg. I racked to the keg last Sunday and connected the gas. I dialed the regulator until the guage read 10 psi, then left it.

I've been checking it twice a day (morning and night), and I'm finding that I have to occassionally adjust the regulator. Sometimes the guage says the pressure has crept up to 15 psi, so I have to dial it back and purge back down to 10 psi. Other times, the guage says the pressure has slipped to 5 psi, and I have to open the regulator until it gets back up to 10 psi.

Is this normal, or do I probably have a leak somewhere? Are you guys normally able to just set it at 10 psi on day one, then leave it alone for the entire week while it carbonates, without ever having to adjust anything?

Regulator creep can happen. There's a poppet valve in the regulator that limits the output pressure. any debris or damage to the seal can result in the pressure slowly (or not slowly) rising over time. This can be fixed by replacing the guts of the reg or simply cleaning it and re-lubing.

As for the pressure drop - I'm not sure what that would be from.

A couple likely possibilities. Could possibly be a regulator guts issue as bryce mentioned or a dying O ring on your keg.
Have you had any beer purge back through the regulator or has the reg been dropped? The pressure drop could just be a result of dialing back the setting and whatevers causing the diaphram to "stick" suddenly releases and the lower setting suddenly showing through.
As for the O-ring, you could have a slight leak under lower pressure, when you raise the pressure up it reflects a 10 PSI until the enough pressure and time allows the ring to seal up, causing the pressure to build up to the 15 PSI, and when you dial it back and purge the pressure the ring slowly releases enough pressure allowing air to start escaping again.
Being as the regulator is the more pain in the ass thing to tear apart/clean/fix, id recommend starting with inspecting the O-rings, replacing them if needed, using some keg lube if you have it, and making sure your lid is angled right to be getting a good seal. If that doesn't work, try the regulator.

It's a brand-new regulator, so I'm doubtful that it's the problem. The keg, however, is a "reconditioned" Corny keg. I took it completely apart and gave it a good cleaning before I filled it with beer on Sunday. I don't have keg lube, so I lubed the O-rings with a little vegetable oil (is that a good substitute?) when I reassembled everything.

When I pressurized the keg, I did hear a lot of hissing around the main lid, until I pulled it up tight enough for some pressure to build up behind it and hold it sealed. However, after that, I haven't heard any hissing at all (except, of course, for when I open up the regulator to introduce more gas into the keg).

I had hoped that maybe the pressure drop was merely the result of the CO2 being absorbed into the beer, freeing up pressure in the headspace for more CO2.

The other troubling thing is the overall tank pressure guage has dipped to just above the red zone, but I'd hoped that was because the tank is in the fridge with the keg, and the colder temperatures caused the pressure to drop. It's a brand-new tank, and it was completely full before I started this (as I mentioned, this is my first attempt at keg-carbing). I'll check it when I get home tonight and give the tank a little swish around, just to see if it still feels like there's a lot of liquid CO2 in there.

What brand/make regulator did you get? I've found that its best to NOT skimp on the regulator. I picked up a Chudnow regulator once but had regulator creep that could not be fixed. I returned it and got a Taprite in it's place. Zero issues with the Taprite.

Also, I would get some actual keg lube to use. Not sure what veg oil will do to the o-rings, if anything. What I do know is keg lube is the correct stuff to use. A little goes a LONG way.

kombat said:

I took it completely apart and gave it a good cleaning before I filled it with beer on Sunday. I don't have keg lube, so I lubed the O-rings with a little vegetable oil (is that a good substitute?) when I reassembled everything.

The other troubling thing is the overall tank pressure guage has dipped to just above the red zone, but I'd hoped that was because the tank is in the fridge with the keg, and the colder temperatures caused the pressure to drop. It's a brand-new tank, and it was completely full before I started this (as I mentioned, this is my first attempt at keg-carbing). I'll check it when I get home tonight and give the tank a little swish around, just to see if it still feels like there's a lot of liquid CO2 in there.

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Go ahead and spend the $3 on the keg rebuild kit and $3 on some food grade lube. The total cost will be a fraction of even one batch of beer.

The oil should work - but if you get any in your beer you're going to kill your head retention. The food grade lube is thicker - you smear it on. It'll stay in place longer and is less likely to cause problems in your beer. A tube will last you for many many years.

The gauge on a CO2 tank is only minimally helpful. It'll show lower in your freezer than at room temp - but it's not really helpful in telling how much CO2 is left in your tank. CO2 is a liquid that boils off to a gas. That means that at room temperature your tank will read about 750 psi until you have used up all the liquid - only then, when the tank is nearly empty, will the gauge start to drop.

a spray bottle of starsan can be very helpful for finding leaks. Also following your hand around all the edges and openings feeling for cold air. If the lid didn't seal well right from the start, the shop might have paired a lid to a keg that didn't quite match up right. I've got quite a few lid/keg combos that are very specific about which ones they'll fit right with and I learned that the hard way with an empty CO2 tank after very similar issues to what your talking about. Some kegs are very particular about needing the lid to be lined up just right when locking in the lid.

BlueZooBrewing said:

a spray bottle of starsan can be very helpful for finding leaks.

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yeah, forgot to mention that. Starsan is awesome for finding leaks. Anything that bubbles is venting pressure.

I had an issue with a brand new reg similar to what you are describing. Turns out there was a bit of debris in it (this can happen to any regulator at any time). It was simple enough to fix though.

1. turn off all gas and disconnect from keg, purge lines with relief valve.
2. disconnect the hose from the problem regulator (if you have a multi-reg you can leave the other hoses attached).
3. close the check valve (red handle) on all the regulators you have and turn on the gas. set all regulators to 0psi except the problem one. Set the one you are having issues with to about 15 PSI. Now turn the gas off at the main tank and relieve pressure with relief valve.
4. Now open the check valve (red handle) and give short bursts of CO2 from the main tank using the main shutoff. give 3 or 4 to dislodge debris and wait about 10 sec between each as the gas is cold and could freeze the debris in place.

This solved my regulator creep. One question I had for people more in the know is can hi pressure hoses be pulled of the barb of a regulator or is it recommended to cut them off? I broke one port on a 3 way manifold pulling the hose off and I was told I should have but it off, but are those valves the same that are attached directly to the regulator?

- Smarch

smarch0 said:

This solved my regulator creep. One question I had for people more in the know is can hi pressure hoses be pulled of the barb of a regulator or is it recommended to cut them off? I broke one port on a 3 way manifold pulling the hose off and I was told I should have but it off, but are those valves the same that are attached directly to the regulator?

- Smarch

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I generally avoid fighting with the barb/hose issue by cutting a diagonal slit in the hose over the barb, not enough to get down and actually hit the barb, but just enough to release the pressure from the tightness of the hose and slide it off easily. Can be done with a scissor, weed snips, knife, whatever. doesn't take too deep of a slice to just slide it off, then you can just cut off the end half inch of the hose and use it as needed. I do that for pretty much any barb fitting just to be on the safe side.