Tapping a keg of beer with a traditional pump style "party tap" will successfully transfer beer from a keg to numerous cups for a single day of enjoyment. However, these simple pump taps dispense beer by forcing air with its accompanying contaminants and bacteria into the keg, spoiling the beer's freshness and producing off-flavours. Tapping a keg with CO2 eliminates these problems and offers the additional benefit of keeping your unfinished keg fresh for days or even weeks, as long as the keg is kept chilled.
Attach the CO2 regulator to the filled CO2 cylinder and tighten the regulator coupling nut with a crescent wrench. Do not over tighten. Close the toggle shut-off valve on the output port of the regulator; the "closed" position is typically perpendicular to the output port and the "open" position aligns the lever parallel to the port.
Secure the CO2 cylinder in an upright position for safe operation.
Slip a hose clamp over one end of the air hose and attach the hose to the regulator hose barb. Slide the clamp over the hose and regulator connection and squeeze to tighten.
Slip a hose clamp over the other end of the air hose and attach it to the keg coupler gas inlet port. Secure the connection with the hose clamp. Lift the keg coupler handle up into the "off" position.
Align the keg coupler with the lugs on the keg and turn it clockwise to lock it into place. Pull outward and then push down on the coupler handle until it clicks (open position). Attach the beer hose to the coupler. Attach the end of this hose to a draft beer tower with a faucet, or attach a dispensing valve to the end of the hose.
Open the regulator toggle valve by pushing the lever down into the "on" position. Open the valve on the CO2 tank by rotating the knob counter-clockwise until it stops.
Adjust the CO2 pressure on the regulator (top gauge on a dual gauge regulator) by turning the handle or screw beneath the dial clockwise until the gauge reads 10 to 12 psi, which is the optimal pressure for lagers and ales.
Draw beer by opening the faucet on the draft beer tower or the dispensing valve attached to the beer hose. Check the temperature of the beer initially and periodically during dispensing; a beer temperature of 2.22 to 3.33 degrees Celsius is necessary for optimal dispensing.
Keg couplers or taps are available in six varieties; D, S, A, G, U and M are types of system keg couplers. Each is specific to a group of beers, with the D-system coupler being used for the most popular ales and lagers. Both single and dual gauge regulators are available for use with CO2 pressured keg dispensers. The second gauge on a dual gauge unit monitors the amount of pressure, or the quantity of CO2 remaining in the cylinder. Refer to your local yellow pages for CO2 canister filling. Search under the heading of Fire Extinguishers or Fire and Safety equipment; CO2 canister filling is available through these sources. Beer kegs can become agitated during transportation; allow beer to settle for an hour or two before tapping. Always begin with a thoroughly chilled keg either by refrigeration or in a tub on ice to prevent foaming and beer waste. Regulators and keg couplers are available as kits complete with necessary tubing and fittings. Single-use CO2 cartridges equipped with an integrated regulator are also commercially available. For information on choosing the appropriate size CO2 canister for your keg needs or removing a CO2 canister, see Reference 1.
Never exceed 60 psi when setting the pressure on the gas regulator. Do not attempt to attach a CO2 tank to a beer keg without the proper keg coupler and gas pressure regulator. Do not drop or throw a CO2 cylinder; secure the cylinder in an upright position and protect it from heat above 21.1 degrees Celsius. Ventilate and evacuate an enclosed area in case of leakage; breathing high concentrations of carbon dioxide gas can be deadly.