Draft Beer Systems: Maintaining Proper Pressure

Keep your draft beer pouring perfectly and improve the quality of your brew by maintaining the proper pressure.

As CO2 enters a keg it displaces your beer at a constant pressure, replacing poured beer by occupying the space that otherwise would be empty. The empty space in the keg is referred to as “head space.” The CO2 fills the head space and maintains the pressure inside of the keg at the PSI set on your regulator. Maintaining a constant PSI keeps your beer perfectly carbonated by preventing the CO2 that’s dissolved in the beer from leaking out of the keg.

Double Gauge Premium Nitrogen RegulatorHow best do you maintain proper pressure? Here’s some tips:

Store your air tank upright
Your CO2 tank will not work properly if it’s not stored upright, and could even cause damage to your regulator.

Find your PSI
Most US-produced ales and lagers dispense well at 10-12 PSI, while stouts or other nitrogen-dispensed brews work well at 25-30 PSI. If you’re having problems utilizing these general guidelines, check with the local distributor from which you got the keg; they may have a suggestion for that particular beer.

Too much pressure? Indicators and how to fix it:
Initially, too mush pressure results in fast pouring, extremely foamy beer. Think fire hose. Foam in over-carbonated beer will appear tight with large bubbles.

Fix over-carbonated beer by immediately adjusting your regulator to a proper, lower level and either pour off a few foamy pitchers or bleed off some of the extra pressure via the relief valve on the regulator. This way, your system can find its balance. If you leave your system at too high a pressure for longer than 24 hours, your keg will be permanently over-carbonated and excessively foamy.

Not enough pressure? Indicators and how to fix it:
If air pressure isn’t high enough, your beer will be over foamy too, but it will look more loose than if there’s too much pressure; small bubbles that are often described as “soapy” looking. Another sign that your beer is under-carbonated is if foam and/or bubbles actually rise into the beer line. If you don’t raise pressure to a proper PSI soon enough, your beer will become flat.

To correct low pressure, first check to make sure your air tank isn’t empty and that it’s turned on. This seems like a “duh” suggestion but sometimes it’s the simplest issue that causes the problem. Next, check your regulator to be sure it’s set at the right level. If the tank is functioning and there aren’t any obstructions in your air line, aaand your regulator is set to the correct PSI, then most likely your regulator or gauge needs to be replaced. Unfortunately, regulators do wear out and typically need to be replaced every 4-6 years or so.

Hope these pressure pointers do you and your draft beer some good. Cheers!

[techtags:DRAFT BEER, DRAFT BEER SYSTEMS, REGULATORS, MAINTAIN PRESSURE, DRAFT BEER TIPS]

24 Comments

  • Amgad March 22, 2011 @ 2:53pm

    Hi,
    My name is Amgad I’m a restaurant and bar manager. my draft beer system is not working (the beer comes out warm) if you can fix it for me please email me back ASAP.
    Thanks
    Amgad

  • Hannah March 22, 2011 @ 3:01pm

    Amgad – Is your keg properly refrigerated? If so, you’ll also want to make sure the beer lines are kept cold so that beer isn’t getting warm en route from keg to beer glass. Are the beer lines in the keg fridge or at least properly insulated?

  • Steve May 11, 2015 @ 5:38pm

    when i first tap a keg (always a craft brew IPA) it tastes great as intended for about 5 days or so. After that, its still okay, but not great like it was in week 1. After the second week, another drop off in taste. Still drinkable, but a far cry from two weeks ago. Am i doing something wrong with my CO2 pressure or is this just the nature of the beast? I use 5 gallon kegs in a refridgerator conversion kegerator. temp 37F, pressure 10-12psi. No foaming issues, great pours every time. (seven foot beer lines took care of the foaming). At 10-11 psi i get bubbles developing above the coupler (suggesting low pressure?) if i raise the pressure just to the point that those bubbles dont form (12-13psi), the beer loses flavor almost instantly (over carbonation?) What am i doing wrong?

    • Caleb Houseknecht May 12, 2015 @ 12:36pm

      Hey Steve,

      A couple of things come to mind. First, an IPA will have a change in flavor as time progresses from the point of tapping the keg. Also, remember the beer in the line is semi-exposed to air, and the oxidization that occurs is unavoidable. The more carbonated the beer is, and the colder it is, the less flavor your tongue processes. If you are experiencing off flavors you may have some problems with your lines or hardware. Make sure to clean your lines after every keg.

      Also, 7 feet of beer line indicates to me that you should be on the higher end of 12-15 psi. I would let the beer sit for a minute or two to reduce temp and let off some of the gas. See how that work. Hope that helps!

  • Ron June 29, 2015 @ 7:43pm

    I’m having a problem with pressure. I set the co2 at 10. But as the night progresses it keeps rising and rising and rising. I turn the knob to where it’s barely on and still it rises. The only way that it stops is to turn off the co2 completely. What am I screwing up.

    • Caleb Houseknecht June 30, 2015 @ 12:49pm

      Hey Ron,

      It sounds like it may be a Regulator issue. Try turning off of the shut off going to the keg. Leave the gas on to the regulator overnight. See if the pressure changes to the regulator, or if it holds…

  • Josh November 21, 2015 @ 6:16pm

    I am having an issue where the pressure seems to trail off while pouring to the point that it stops. I come back 5 minutes later and the pressure is good, but then trails off throughout the pour. The CO2 looks good and gauge indicates plenty of gas. I have the pressure set at 12psi. I don’t see any kinks in the line or anything like that. Any ideas? Thanks

  • Chris November 24, 2015 @ 3:35pm

    I have a keezer with three kegs that feed a tower in my bar. The length of beer line for each is approx 12 feet (3/16″ line). Beer is stored at 36 degrees. Where should my psi be set? Currently around 12 – pours a little slow, but beers seems adequately carbonated. Trying to avoid over carbonating, but everything I read indicates I should have the psi set much higher with the length of line I have.

  • Jay March 2, 2016 @ 9:39pm

    Hi. So I tapped my beer this pass Sunday and it pours out slowly but taste carbonated. The psi is set to 12. I have 3 lines hooked up but only 2 are in use (it’s a keeper). I’m looking to get that 1/2 of foam? Should I raise the psi? Shake the keg up? Thanks for any help you can give.

    • Caitlin Hartney March 4, 2016 @ 9:16am

      Hi, Jay. First, please don’t shake a keg! Second, there are multiple variables here, so we would need more information to provide a helpful answer. What temperature is the keg at? What style of beer is? it?

  • Mike March 3, 2016 @ 11:26am

    I have a Guinness set up with 75/25 Nitrogen/co2. I set it up at 30psi and somehow it got to 38 without my noticing. The head seems fine, however, I am unable to draw a shamrock in the head like I’ve done before. It seems like the head is too loose to hold the lines drawn. Does anyone know if this might be caused by the pressure being a little too high? The important part is that it looks and tastes right, but would still like to be able to add this little feature.

    • Caitlin Hartney March 4, 2016 @ 9:12am

      Hi, Mike. Yes, your problem is probably due to the pressure being a bit high. Hope you get it sorted out before St. Patrick’s Day!

  • Charlie S March 3, 2016 @ 4:38pm

    I just purchased a new kegarator and can’t get the CO2 set right to get rid of a mug full of foam and after settling for a bit foam goes down. Please tell me a good setting….book says between 10-12 but still major foam.

    • Caitlin Hartney March 4, 2016 @ 9:14am

      Hi, Charlie. Between 10 and 15 is the general recommendation. The first pint poured may be a bit foamy if the room is considerably warmer than the beer. When the cold beer hits the warm metal it releases CO2. The foaming should improve on subsequent pours.

  • Randy May 3, 2016 @ 8:15pm

    Hi all,
    My neighbor just gave me an old Keg-erator which I just cleaned and hooked up. I installed new lines and a new C02 tank. At first I had no pressure, but I think the regulator valve from the C02 was not fully open. I adjusted that and I have beer flowing, but without much pressure though the tank is turned on full. My pressure indicator I think is broken, it’s not showing any pressure at all, but there is beer flowing through the line. Would replacing the pressure gauge provide any help or does anyone have another suggestion?

    • Caitlin Hartney May 5, 2016 @ 2:53pm

      Hi, Randy. Does the dial move at all when you move the screw or knob that adjusts pressure?

      • Randy May 6, 2016 @ 2:49pm

        Caitlin
        It does move now. However it won’t go past 10 psi no matter the adjustment and its jerks rather than moves smoothly. I have pressure in the system now, but the beer is very foamy. I think I’m having trouble with the right adjustment on pressure

        • Caitlin Hartney May 6, 2016 @ 3:14pm

          It sounds to us like the bladder or adjustment screw is shot. Unfortunately, that kind of problem calls for a new regulator.

  • Rich June 14, 2016 @ 8:44am

    I have a new kegco fridge with a commercial regulator (2 tap). I have to run 2-4psi in order for it not to foam up the mug. It pours clear but extremely fast. Any reccomendations? It’s at 36 degrees.

    • Caitlin Hartney June 14, 2016 @ 2:30pm

      Hi, Rich. We don’t carry this line of products, so we hesitate to speculate as to what might be wrong. Your best bet might be to contact the manufacturer directly.

  • Billy June 26, 2016 @ 1:14pm

    Hello..I am having Co2 issues..I have an IPA,keep the pressure between 10-12 psi,temp at 38 degrees.The pressure keeps spiking to 20-30 psi.I turn off the co2 and bleed the pressure off the keg and it drops back down but Ina few hours spikes again??

    • Caitlin Hartney June 28, 2016 @ 2:23pm

      Hi, Billy. It sounds to us like your regulator bladder is shot. We recommend replacing the regulator.

  • Mike July 25, 2016 @ 10:06pm

    im a night time bar managaer and my draft machine comes out extremly foamy and i have to adjust the flow nob to the lowest point where it takes forever to pour a mug of beer cause it just foams up how can fix this? thank you

    • Caitlin Hartney July 26, 2016 @ 10:25am

      Hi, Mike. Our draft specialist Jim should be able to help you troubleshoot the problem. You can email him at jimrozycki@kegworks.com or give him a call at 716.929.7570 x198.

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