Newbie CO2 questions

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418Brewing

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Okay, so I've done some research but it can be tough sometimes phrasing a question exactly right so that a Google search brings you to the answer to that question, rather than some other question.

I have a wheat beer in the keg that says ~3.10 volumes so I put 20psi on it at 40F. The beer is carbonated, but tastes flatter than it should and comes out pretty foamy.

I see people talking about "serving pressure" and I assume that's the same as "slow force carbonation" which is what the chart I'm reading shows. Just to be clear - "serving pressure" has to be whatever creates the correct amount of carbonation at the correct temperature. Dropping it under that would be like leaving the bottle open - it'll go flat. Right?


The bigger issue I'm having is a slow leak (or leaks) in the CO2 side. I have barbs and clamps (worm drive kind) and I've got them clamped down about as tight as I dare. I have a dual body regulator and if I close the output valves, open the bottle, and then close the bottle it'll hold pressure indefinitely. No leaks there. As near as I can tell everything else leaks except the kegs, which will hold pressure if disconnected. The 3-way manifold has valves - if they're closed the upstream pressure drops off. Charge that back up, open the valves, each one hisses for a little while as each leg repressurizes.

Nothing I've tested bubbles. The leak is where it'll drop to about 5-6psi (from 20psi) over the course of about 12 hours. I'm getting to the point where I'd almost rather just pay someone to come make the problem go away.

Ideas?
 

Wables

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I just got a new regulator and there was a leak in the body of the regulator. The big "nut" under the adjustment knob was not fully tightened. No more leaks. I'd spray the entire system with a bottle of star san to see where it is coming from.
 

camonick

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~3.10 volumes so I put 20psi on it at 40F. The beer is carbonated, but tastes flatter than it should and comes out pretty foamy.
Is your liquid system balanced to serve at 20 psi? You’re correct about leaving the serving pressure the same as your carbonation pressure. When you say it “comes out pretty foamy”, that makes me think you don’t have a balanced system. That knocks the carbonation out of solution which causes the foamy pour and sense of flat beer. If you have the beer carbonated at 20 psi, you’ll need 20 feet or more of 3/16” liquid lines to create enough restriction to counteract the high pressure. Barbed fittings that are 1/16” larger than your gas tubing eliminate a lot of leak problems. The tubing needs to be heated to push it over the larger barb, but can be done. Replacing the worm type clamps with the Oetiker style will help a bunch too. The more popular option now is to use 4mm EVABarrier tubing and Duotight fittings for both sides.
 

wepeeler

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Once your kegged is fully carbed, and assuming there are no leaks on the keg side, the beer should stay carbed up. Until you serve enough to drop the pressure. Then you need to attach it back to the CO2.

If you know you have a leak on the CO2 side, you're better off disconnecting the attachments and slapping on some plumber's tape. Check the gaskets as well and replace if needed. Sometimes they leak if they are too tight. As mentioned above, if your tubing is too large for your connectors, get the right size tubing. You can bring the regulator to a HB shop, and they can sort you out. Also, get better hose clamps. I can't tell you how many times I had leaking until I smartened up and put hose clamps on nearly every connection I could think of.

As for what @camonick said - 20 psi should shoot beer out way faster than you need, causing a lot of foaming. I've seen standard pre-made liquid lines as short as 3 feet, and that is typically way too short, depending on your system. 5 feet is even short. I've gone to mostly 7-10 feet of liquid tubing, and this allows good beer flow and much less foaming. You have to know your system to figure out the ideal tubing length.
 
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CascadesBrewer

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I have a wheat beer in the keg that says ~3.10 volumes so I put 20psi on it at 40F. The beer is carbonated, but tastes flatter than it should and comes out pretty foamy.
You are correct. You wanted the beer to stay at 3.1 volumes, you would have to keep the pressure at 20 PSI. If you reduce the pressure, the carbonation in the beer will gradually reduce back to the "serving pressure", but only after you have dispensed some of the beer.

As mentioned already, if your lines are not long enough the beer will gush into the glass, pushing out a lot of the CO2 from the beer, leaving what seems like flat beer. With my setup (38F using 5ft to 6ft lines and picnic taps), around 12 PSI is the sweet spot for me. Much above that and I start getting foamy and flat pours.

If you can submerge any connection underwater, you might have beer luck finding leaks. I have had good luck with a spray bottle of dish soap and water (maybe 20% dish soap) to find leaks.
 

Genuine

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I keep a bottle of soapy water around just to check for leaks. My most recent one was an ever slow leak from the keg lids PRV...which took about 2 weeks for it to deplete a 5lb bottle. However, with some spraying and very close watching, I noticed bubbles coming from the PRV, which ended up being the culprit.
 

wepeeler

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I use a spray bottle of Star San to check for leaks. It bubbles like crazy if there is a leak, and that way you're not spraying soapy water all over your equipment. Especially if you have a keezer full of kegs. You don't have to worry about wiping the Star San off.
 
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418Brewing

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Does your gas distributor look like this:
Those "red" valves can be a little touchy, as in leak when touched or adjusted. Is it brand new?
That's exactly what I have. Considering that the system seems to leak from everywhere, that makes sense as a culprit.

Go find a Perlick 650SS adjustable flow control faucet, it will help you adjust your restriction at the tap. This will cure a variety of line length, balance and carbonation level issues.
I was suspecting that this might be a solution. My styles tend to go towards high-pressure requirements, so it may be worth the investment.


The keezer I bought has a 4 tap tower and came with all the Evabarrier plumbing. The regulator was a single body style, with Duotight T-fittings to split the gas to four kegs. I had a leak with that, in the regulator I believe, and I knew I'd probably want a dual-body regulator eventually so I got that. The Amazon seller pulled a "new model upgrade" on me to one that, instead of having barb connectors screwed onto flares (which I could remove to put on my Duotights) it had valves with built-in barbs. Then the manifold seller did basically the same thing, shipping me the barb model instead of the flare model, so I bought some barb ball-lock fittings and ran some quarter-inch beverage tubing to everything.

So gas-side I'm running barbs, bev-side I'm running Duo-tight/Evabarrier (4mm on bev side). Bev lines are about 6 feet each.

I actually have a leak on the flare-side of the Duo-tight fitting on one of my bev lines - it's slow, so at the moment I'm just disconnecting it except when I need to do a draft. I'm not worried about it, just mentioning it in case someone knows a simple fix - I think if I tighten it I'm going to break it. I have a couple spare Duo-tights, I just need to swap one in.

Gas side... I have the regulator sealed up tight and working. I'm not excited about buying another one, so either I'd want to keep using tubing for barbs, or just boil the ends of the 5mm ID Evabarrier and wrestle it on there. Looks like I need to replace the manifold which, thankfully, I got refunded for because they sent me the wrong one.

Questions:
1. What's a good manifold to get? I want a 3-way and a 2-way with valves. That'll let me serve any combination of kegs off a dual-body regulator.
2. What's a good foot-per-PSI for the beverage line with 4mm ID Evabarrier? What I read said that 5-6 feet was good for "most applications" with 4mm ID, but apparently that's not the case for my application.
3. Is there an inline flow restriction compatible with Duo-tight? Just thinking that if it's cheaper per-line than an adjustable Intertap faucet that might be the better solution.

Finally,

Thanks for ALL the help. Seriously. It's great to see a huge response like this to help.
 
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418Brewing

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I'd like to avoid a lot of trial and error, so if there's some way to plug in PSI and line ID and get the feet needed that would be good to have. I'm probably not going to serve the exact same beer every time from now on.

I've ordered an adjustable flow tap to see how well that works as a solution, but I like having multiple solutions in planning stages at least. Considering the hassle of changing lines in the tower, I would really prefer something that solves the problem in a single go - I don't want a library of various length line I break out for every new beer to dial it in if there's another option.

I'm also going to replace all the clamps in the hope that the manifold is NOT the primary source of all the leaks, but if someone has a recommendation for a good quality manifold I'd like to hear it. It's not exactly fair to say "oh, do you have this kind of manifold? Those are crap" and then not have any input on what isn't crap.
 

CascadesBrewer

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I'm also going to replace all the clamps in the hope that the manifold is NOT the primary source of all the leaks, but if someone has a recommendation for a good quality manifold I'd like to hear it. It's not exactly fair to say "oh, do you have this kind of manifold? Those are crap" and then not have any input on what isn't crap.
I have had a manifold that looks like that one for many years and it has worked fine for me. I am sure that quality varies, but I would not have an issue with purchasing that manifold.
 

jerrylotto

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As you lower the temperature, solubility of carbon dioxide goes up. At 33F, you can maintain 3.1 vol at about 15 psi - a much more manageable serving pressure - and I would question if you really want that much gas. 2.4 -2.7 is the "normal" range for wheat beers.
 
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418Brewing

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Cheers!
Thanks, that tells me I'm off by maybe 2 feet. The suggestion here is that my lines need an extra 5 feet at least. The probable culprit is the "e" value in that equation which I don't have for Evabarrier - vinyl tubing is probably different, and the value that's pre-populated.

As you lower the temperature, solubility of carbon dioxide goes up. At 33F, you can maintain 3.1 vol at about 15 psi - a much more manageable serving pressure - and I would question if you really want that much gas. 2.4 -2.7 is the "normal" range for wheat beers.
That's a good point. I had originally planned to serve at 44F (it's German-style beers primarily, I don't want them cold-cold.) With the foaming I tried dropping temp to 40F to tame it, which seemed to make a little difference, but you're right - I'm probably a little overgassed now. I don't really want to go much colder than that.
 
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418Brewing

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Replaced all the clamps, and replaced the foamiest beer's tap with a variable flow tap.

Regardless of flow rate, I'm still getting mostly foam. So I'm guessing line length isn't the problem.

Still have a CO2 leak somewhere past the regulator. It's faster with the manifold valves open, but it's there when they're shut, too.

I'm strongly considering just building something like this:
1635515661685.png


And including check valves/shutoff valves below the regulators. I'll have to heat and jam a 5mm ID Evabarrier line over the barb on the regulator (as well as buy a bunch more Evabarrier and Duotight stuff) but then I'd have a nice mad-scientist control panel outside the kegerator so I'm not sitting in front of it with the door wide open every time I need to mess with stuff.

Actually now that I think about it - if I'm going that route I could dress it up a bit more by using more metal parts wherever I can. Mount it on the wall behind the kegerator. Any ideas/suggestions on plumbing or other industrial/steampunk-y kind of hardware I could adapt with relative simplicity?
EDIT: started a new post for that - Duotight CO2 Regulator Board Ideas/Planning
 
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Just out of curiosity, how long did you carbonate your beer for?

The reason is that if the beer hasn't reached the equilibrium concentration of co2 at the pressure and you close the gas valve at 20psi, the pressure will continue to drop until it comes to equilibrium. The final pressure at which it will settle depends on your head space (therefore the volume of beer) and temperature.

Carbonation process actually takes awhile if you just fill headspace with CO2 at the "right" pressure. You could either try to maximize the co2-beer interaction by shaking or you could give it higher psi to make this process go faster. I don't really know the kinetics of co2 dissolving in water (if anyone knows, please let us know) but my experience is that it takes about 12 -24hrs at the "right" pressure without agitating.

Something to think about. If you are sure that it is a leak, then everything I say is irrelevant.
 
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418Brewing

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Just out of curiosity, how long did you carbonate your beer for?

The reason is that if the beer hasn't reached the equilibrium concentration of co2 at the pressure and you close the gas valve at 20psi, the pressure will continue to drop until it comes to equilibrium. The final pressure at which it will settle depends on your head space (therefore the volume of beer) and temperature.

Carbonation process actually takes awhile if you just fill headspace with CO2 at the "right" pressure. You could either try to maximize the co2-beer interaction by shaking or you could give it higher psi to make this process go faster. I don't really know the kinetics of co2 dissolving in water (if anyone knows, please let us know) but my experience is that it takes about 12 -24hrs at the "right" pressure without agitating.

Something to think about. If you are sure that it is a leak, then everything I say is irrelevant.
Good points - I'm losing pressure without the kegs attached so it's not that. All kegs disconnected, all valves open or closed on the manifold, I lose pressure.
 
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