We are occasionally seeing excessive foaming both at our bar and out in the market via kegs. The bar is served directly from the serving vessels, and we keg off for local bars. Does anyone have any thoughts as to why this is occurring and any recommendations to fix it. Thanks in advance.
Excessive foaming can have many sources and can be a bear at times to fix... With that said, there are a few questions that come to mind.
Is the beer over carbonated? How are you measuring the CO2 volume? If you are using a device to measure the CO2 volume, when was the last time the device was calibrated?
What is the actual temperature of the beer coming from the taps?
Are there any air leaks in the beer lines at any of the barbed connections? If you are using quick-disconnects, are the o-rings in good shape? Make sure there isn't any nicks in them.
As far as the kegs, if you are filling the kegs too quickly, it can cause foaming issues. If the beer is in fact over carbonated and there isn't enough pressure in the keg to keep the CO2 in solution, it will cause foaming.
As far as maintaining the kegs at accounts, it can be tricky as you may not know the details of their draft system. Try serving a keg at your location and troubleshoot the foaming by playing with CO2 pressure to find an optimal psi to serve the beer without foam. You MAY then be able to take this knowledge and relay it to the accounts keeping in mind it may not be that easy since there are tubing restrictions and other variables that come into play with outside accounts.
Assuming their isn't an infection issue, foaming can usually be solved with finding the balance between restriction, pressure, and temperature.
I know I raised more questions than solutions, but hopefully these questions will help you zero in to a solution.
Based on your post info, the most likely culprit is over carbonation of the beer batch. Do you have a way to measure (Zahm)?
Make sure your bars are allowing 24 hrs for the keg to acclimate. Otherwise overcarbed sounds like the culprit.
Perhaps there are a few bad kegs in your float.
Whereas over-carbed beer is the most likely reason, if the keg rubber gasket is cracked and no longer pliable, this could be the problem. When buying old kegs, this is a risk. The UV in sunlight attacks the rubber. (Ideally, don't leave your kegs out in the sun without caps!)
I have found if I have a keg returned as a partial that I mark the keg or record the keg number and be sure to disassemble and check the keg if it occurs again. I have found pieces of scrubbie or such wedged in the keg valves on these kegs.
Last edited by Moonlight; 04-19-2010 at 09:47 AM.
Draft beer is remarkably complicated. You need to balance temperature, pressure, restriction, and carbonation levels. Much of the info you need to do so is at draughtquality.org
If the foaming issues happen with the same batch, whether it's served direct or from keg, then I would suspect over carbonation.
However, if it isn't that consistent, then you need to look at storage conditions, yeast count, etc. when it occurs.
Certainly - as has already been said - filling kegs too quickly can allow the beer to absorb CO2 from the empty keg (if you are using CO2 to purge). This will initially form microbubbles which eventually dissolved over the next 48 hours or so and increase the CO2 level.
The same can also occur if you are using N2 to purge kegs, with the beer absorbing N2 similarly and with the same dispense problems as a result.