There are a variety of reasons your beer is coming out flat. If the foamy head of your beer disappears quickly and the flavor is “skunky” you’ve got a problem. This can be caused by: dirty glasses, a sluggish regulator, applied pressure is set too low, CO2 is turned off at night, contaminated CO2, incorrect temperature or moisture in your air system. Most carbonation problems begin with the CO2, so make sure your pressure is set correctly.