Beer Enemy #1
Reason # 1 it’s Enemy # 1: If you plan on selling draught beer you need to use some sort of pressurized gas to “push” the beer through the lines. Usually either straight CO2 (direct draw – kegs directly underneath the tap) or a blend of CO2 and Nitrogen for a long draw, where the kegs are a distance from the taps.
However, in some cases we see establishments using an air compressor to pressurize the system.
Most long draw systems require about 22-25 PSI of pressure to push the beer through so the flow speed is 2 oz/second. A domestic keg of draught usually requires about 14psi of CO2. If you use 100% CO2 at 22psi and the beer only needs 14, guess what happens? You got it, it turns to foam because it’s over carbonated. If you put in a blend of CO2 and Nitrogen, it’s perfect because your blend has been designed to add 14 psi of CO2 and 8 of Nitrogen (14+8=22). Nitrogen doesn’t break into beer (it’s inert), so your beer is balanced.
So, if too much CO2 makes your draught foamy, what happens when you put in no CO2? When you are using an air compressor to push the beer through the system you are adding zero psi of CO2 so your beer goes completely flat. Using an air compressor gives you flat draught.
It also causes your bartenders to fill the pints right to the top because there is no head. This costs you 20 cents a pint in over pour, or $20.00 a domestic keg.
Reason # 2 it’s Enemy # 1: This is why some people don’t enjoy draught beer. Oxygen causes beer to oxidize which makes it taste like wet paper or cardboard. It also makes it cloudy and in extreme cases, makes it sour. We would all agree that these are not positive attributes in draught. Oxidation occurs within hours of putting air into a keg.
If you are using air, make the change. There are many solutions. Ask your brewery rep, draught service company, or reach out to us (we don’t sell beer gas). Air compressors are antiquated technology. Thirty years ago, when a tray of draught sold for a dollar and it was pushed through plastic lines with air, you got what you paid for. At $8 a pint now, using air is simply unacceptable in every way.
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