Carbonics Homepage Carbonics Troubleshooting Guide

Foamy Beer!
foamy beer

Beer is Foaming too much!  The troublesome end of the keg!

The last third of a keg is foamy. As the beer is replaced by carbon dioxide in the keg, the area of contact between the gas and the beer stays the same, but the volume of beer is smaller. This allows the beer to dissolve the gas more quickly.  This means that more carbonation gets absorbed into the beer, and your beer can more easily become overcarbonated.  This is not usually an issue of the keg is used within a few days to a week.  But for kegs that sit tapped for weeks at a time or longer this can become a concern, especially if there was just slightly too much co2 pressure on the keg to start with.

over carbonated beer keg

You can see above that you draw your beer from the bottom of the keg, so you don't begin to get the lighter, foamier over-carbonated beer until you reach the last of the keg.  Ideally, we keep it from getting over-carbonated in the first place.  But if it does happen, there are a couple of tricks you can use.

Here's what you can do:

1.  Keep the beer cold.  The colder the better. 
    34 degrees is better than 38 for reducing foam in slightly overcarbonated beer

2.  De-gas the keg.

  • Shut the gas off to the keg at the regulator (hopefully there is a shut-off valve)
                           regulator shut off valve for troubleshooting beer dispensing issues

  • Open the safety release valve on the keg to release the gas
                      Keg coupler safety release valve
    The safety release is circled in red, pull the ring out to release the head pressure on the keg.

  • Shake the keg for 15 seconds

  • Wait 3 minutes, then open the safety release valve again to vent the carbonation you just stirred up.

  • Turn the gas back on to the keg at the regulator.

Do not make the mistake of trying to adjust the pressure of the regulator down, because the reduced pressure will allow the Carbonation in the slightly over-carbonated beer to "Break out" of the beer and foam in the line, just behind any connections or the shank of the faucet.  This will make the problem worse, not better.

To make sure your regulator is set to maintain the perfect, ideal conditions for your beer, call one of our Draught Beer specialists to come give you a free estimate for the repair or installtion of a Beer Dispensing System.   Intalls    Repairs

Keeping this keg COLD during the last third is even more critical, as the volume of beer in the keg decreases and the beer absorbs more Carbon Dioxide, then it becomes easier for carbon dioxide to be released from the beer due to problems.  Problems like dirty lines, kinked lines, lines being crushed under another keg, bacteria in the lines, pin holes in the lines, and warm beer will cause excessive foaming during the last third of the Keg because the beer is MORE carbonated during this stage.  As a general rule, if there was a little too much foam during the middle 3rd of the keg there will be way too much foam during the last third of the keg!    Of course, making sure that you are not using an excessive amount of Co2 is also a good step in preventing the last third of the keg from over-carbonating.  You'll need to know the specific carbonation PPM (parts per million) that the beer in question calls for, and calculate how much co2 you are applying to the keg, depending on the gas blend you are using.  If you are unfamiliar with this, we'll send someone out to help you!

The best way to fight this is to make sure all conditions are as close to ideal as we can realistically make them.  The lines are straight or smoothly curved (no "elbow" joints), the pressure is just high enough to dispense smoothly, not too much.  The lines are clean, the beer is cold, and the lines are being cooled, chilled, or at least insulated all the way to the dispenser.   Remember, if the beer warms it will release the co2 gas.. so if it gets warm in the tubing on the way from the back room or beer cooler out to the bar, then it will foam IN THE LINE, and this will cause your beer at the dispenser to come out alternately clear and foamy, depending on how many "hot spots" you have along the line.

One good way to fight warm lines is running a chiller line along the beer line, all insulated together in a bundle.  Usually glycol chillers are used for this.  Extremely short runs should not require such an elaborate solution.  We can install or repair your Draft beer system!

Call 713-944-7900 to schedule a Service Call.
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