What Causes Beer Foam?

beer foam

We all know that too much beer foam is a bad thing – it’s easy for customers to spot a pint with too much foam and it also contributes to waste. To manage draft beer foam (also known as beer head) and the waste it produces, you need to keep an eye on two key elements:


1. Pressure

Maintaining the proper temperature and right level of CO2 pressure once the keg has been tapped is a balancing act. The safest bet is to work with an experienced draft technician to determine the right gas blend and pressure.

When CO2 pressure is set too high, gas is pushed to the top of the keg quickly, and foam results. When CO2 pressure is too low, little or no foam amounts. In both situations, check the regulator for correct pressure settings.

Sometimes the problem is further down the line. Follow its path to be sure it isn’t crimped, blocked, or otherwise obstructed.

Another best practice is to let the keg sit untapped for 24 to 36 hours. Consider how a can or bottle of beer erupts when it’s shaken and tossed around. Your keg may have been jostled around in the journey from the truck to your bar. Let it settle, just to be safe.


2. Temperature

When kegs get too warm, excess carbon dioxide is released, causing foam to erupt and the beer to go sour and become cloudy. About 25 percent of foam is beer, so allowing foam to accumulate in the keg cheats you out of sellable product.

Store beer at a constant 38 degrees Fahrenheit. To prevent foaming once the beer leaves the keg, make sure the lines can maintain the same ideal 38-degree temperature.


draft beer waste ebookToo much foam is just one of the factors that contribute to waste. To learn more about all seven top waste offenders (and how to remedy them!) download our free eBook: Getting Wasted? How to Reduce Draft Beer Waste and Radically Increase Profit.