Whenever I go to get a pint from the keg, the first pint is always foamy. I have to fill the glass up about 1/3 of the way and dump it out, just to the pour actual beer. I usually carbonate by setting the keg to ~12 psi and letting it sit until its ready. 2nd beer, 3rd beer, etc. don't seem

I have heard that keeping the fridge very cold (~40 degrees) will mitigate this, but I don't always want my beer that cold. Any other options?

5 Answers 5


How long and what is the diameter of the tubing from the keg to the tap? If the tube's resistance is not what it should be, it could be causing the foam issues. There's a good explanation and formula here.

  • Thanks for that link, plugging in some estimates looks like I need about 5.75 feet of tubing and I only have around 4.5 feet right now. The next keg that goes in I will try playing with the psi to make my tubing length work and see if that formula holds true.
    – benr
    Commented Nov 11, 2010 at 4:16
  • 2
    I reset my pressure for the length of tube I had based on the formula at the link you mentioned, and the problem is gone, thanks!
    – benr
    Commented Dec 9, 2010 at 19:01

Not sure if this is related, your issue seems like it would be more caused by line length and/or pressure, but one of the tips to reduce foaming I learned while bartending was to always pull the tap at the bottom, vs the top of the tap handle. The reasoning is that you get the tap fully open much more quickly by snapping the whole tap open rather than using your whole arm to pull the top of the handle.

The more time the tap stays in a not-fully open state, the more turbulence the expressed beer goes through as it navigates the valve. The split-second difference may not seem like much but once foam exists in the glass, the rest of a normal pour just exacerbates the problem.



I have this same issue and it's caused by the temperature differential between the beer lines (inside the fridge) and the tap (outside the fridge). Once the tap cools down after a couple of pints are poured the problem goes away.

Not much to be done about it without completely changing the set-up and mounting taps in a flooded font.

  • My kegs are in a normal size fridge with the taps mounted on the front. As a test I could try cooling the taps with ice and then pouring a beer :) Not a long term solution, but it would be interesting to see if it worked.
    – benr
    Commented Nov 12, 2010 at 1:55

Several factors play a role in the quality of the beer poured from a keg. The major ones are:

  1. Beer Temperature: This will affect how readily the beer absorbs CO2. Colder beer absorbs CO2 into solution more readily. The lower the temp. the lower the pressure required to obtain a given number of volumes of CO2.

  2. Keg Pressure: Along with beer temperature, this will control the actual volumes of CO2 in solution.

  3. Beer Line Inside Diameter: This provides resistance, keeping CO2 in solution by slowing the pour.

  4. Beer Line Temperature: Warm beer lines will warm the beer as it travels from the keg to your glass, causing a release of CO2.

  5. Beer Line Length: This provides resistance, keeping CO2 in solution by slowing the pour.

  6. Beer Line Rise to Tap: The height of the tap from the center of the keg. This provides resistance, keeping CO2 in solution by slowing the pour.

Go to the site I cited below and perform the calculations yourself as they are very dependent on your unique requirements. To say just use X' of tubing without knowing all of the other variables is not sufficient to fully answer your question. Having the correct measurements for each of the factors is pretty simple, the hardest probably measuring the rise from keg to faucet. The site has examples and I think you'll find that at the temperature and pressure numbers you provided, 5-6' is more closer to what you're looking for.

All information taken from: http://www.brewersfriend.com/2009/07/18/getting-a-good-pour-kegged-beer-co2-line-length-and-pressure/


Professional beer bartender here. Clear the first inch or two of beer that sits in the uninsulated part of the faucet and then shove the glass under the faucet at an angle. You waste about half an ounce beer in the form of foam and the actual beer at proper temp comes out sans foam resulting in the normal half inch of head at top-off.

Experiment with this...

Result. .05 oz. waste or 3 to 4 oz. waste. Your choice.

The time to do this is equivalent to the time required to quickly touch your index finger and middle finger as fast as you can. You have removed the warm foamy head of the faucet.

My boss still doesn't understand this.

5% loss compared to 13 to 20% loss depending.

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