I have a two-tap kegerator which I use to dispense commercial 5-gallon kegs. My lines are about 3 feet long1 and I keep my pressure at 10psi and my temperature relatively cold.

Whenever I draw from the tap, I get beer immediately. It looks like a great pour. But always, about half a second after opening the valve, the beer coming out turns foamy for about a second and then returns to normal. This produces enough head that my glass always ends up being half foam. If I have a pitcher that I'm filling, or if I have two glasses and I can run the pour from one to the other, the rest of the pour will be excellent with no foam.

Why does this happen? I have always had this problem with my setup. I used to keep my pressure at 15psi and dropped it to 10psi (and I like it - I think I'll end up on 11-12psi). But that hasn't helped this problem at all. I also tried lowering the temperature on the kegerator. This also hasn't helped. These are things that I feel are just general tips to try to reduce foam. But I feel like there's something specifically wrong with my setup where air is getting in the line somehow.

This problem happens on both taps. This problem happens no matter what keg I hook up. I have used Kegcraft kegs from Half Acre Chicago, as well as commercial kegs from various craft brewers available in Chicago. They all have the problem. This problem has persisted across CO2 tanks as well.

I'm using Perlick 525SS tap handles. Am I missing an O-ring somewhere? How can I test this? I'm sick of having this problem!

1Edit: I estimated three feet when I wrote the question. The line is perhaps actually four, maybe four and a half feet. They came as part of a kit, and I did not cut them. I don't know exactly how long they are, but they are sufficient length to change kegs, clean, and otherwise maintain the set.

  • 1
    I have the same problem with my home system, and the system I set up at the office (owning your own company means having beer on tap!) The first pour is a foamy mess, but subsequent pours are fine. When I look at the line before the first pour, I can see there's an air (gas?) gap where the line reaches its highest point. My guess is that CO2 has been released from the beer forming the air gap. When the air gap reaches the end of the line, the flow speeds up making the subsequent beer foamy. What I don't understand is why the gap forms at all. Commented Oct 17, 2013 at 4:59
  • Is the tower cooled? My kegerator has a fan blowing cold air through a tube to the top of the tower. If the tower is not cooled, the beer in the lines within the tower is going to be warmer and the CO2 will come out of solution.
    – jalynn2
    Commented Oct 17, 2013 at 17:41
  • @jalynn2: I flagged your comment here because it should be turned into an answer. I am ordering parts to cool the tower and will know for sure this weekend, I hope! I cannot imagine that I should be lengthening lines which are already sufficiently long for maintenance. Commented Nov 7, 2013 at 4:23
  • I'm afraid I can't turn the comment into an answer - @jalynn2 will have to do that.
    – mdma
    Commented Nov 7, 2013 at 14:11
  • thanks for taking a look. I'll likely get my equipment on Monday and know if this was the issue by mid-week next week. If this is the issue and @jalynn2 hasn't added it as an answer, then I'll do it myself. Otherwise, I'll buy more hose. :) Commented Nov 8, 2013 at 17:38

3 Answers 3


I can think of a couple reasons. One is that the beer is over carbonated...maybe not literally, but it indicates your system may be out of balance. The other reason would be if you had a long line from the keg to the tap. The line is warmer and the CO2 comes out of solution in the line.

  • My lines are about 3 feet long and are contained within the kegerator. So they should be at the same temperature as the rest of the system, which is close. I do not have an exact temperature control but about 36 degrees. What do you mean that my system may be out of balance? Out of balance how? Commented Oct 16, 2013 at 17:16
  • 2
    Beer line has resistance to it that drops the pressure over the course of the run. The objective is to have the beer come out of the tap at just about 0 psi. To do that, you match the amount of beer line you use to the pressure you're serving the beer at. Here are some resources. beersmith.com/blog/2011/07/14/… brewersfriend.com/2009/07/18/…
    – Denny Conn
    Commented Oct 16, 2013 at 18:02
  • Also franklinbrew.org/wp/?page_id=98 and byo.com/stories/item/…
    – Denny Conn
    Commented Oct 16, 2013 at 18:04

I would increase the length of your lines. Three feet is pretty short. Using the links provided by Denny Conn should give you a better idea of what you will need to increase resistance and prevent foaming. Keep in mind that the diameter of the line also plays a big roll in resistance, not just length. The same goes for the difference in height from where the beer leaves the keg and where it is dispensed.

  • The beer is directly below the tap. I believe I have a 3/16" line, so it seems I need 1.8 PSI per foot. That means I really should have at least five feet of beer line to maintain at least 10 PSI in the keg. But when the tap is only a foot and a half above the keg, do we really need this distance? I guess just to have pressure.... Commented Oct 17, 2013 at 17:37
  • That we are having this conversation indicates that you need longer lines. Tubing is also quite cheap, so purchase 5 feet or more and reduce the line until you are happy.
    – kenyabob
    Commented Oct 18, 2013 at 18:31

While I still have not completely solved this problem, I did find one thing that was definitely causing a problem. One of the gas lines had a rubber insert where it connected to the keg tapper. I cannot find an image online of what I have, but it had a collapsed slot in it that did something to regulate gas flow. I couldn't figure out the purpose for it, but only one of the two gas lines had it. This was causing the two taps to have different pressures.

So while trying to find the best pressure, one of the taps always was too low or too high in pressure. This was causing confusion and preventing me from properly calibrating the system.

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