Temperature

A frequently seen issue is attempting to dispense beer from a warmer keg than ideal, or temperature fluctuations from keg to glass. Most draught beer should be served around 36-38° F. With the beer's carbonation, its CO2 (carbon dioxide) gas is quite sensitive to temperature changes causing it to foam. For optimal system performance, beer temperature must be consistent throughout the system.

• Even slightly warm beer will foam when poured into a glass. A recently delivered keg is a common cause of a temperature problem. Allowing the keg to rest in refrigeration for a full day before dispensing is essential.
• Anywhere there is a warm temperature between the keg and faucet, carbonation will escape the beer forming foam in the lines. The air space inside a kegerator's dispensing tower is notorious for this. Ensure the system design does not allow the beer's temperature to change anywhere.
• Along with the issues noted earlier, continually dispensing foam decreases the beer's carbonation, and flat beer will result. Avoid the mistake of changing the prescribed pressure to compensate for foam issues. Patiently wait for the beer to arrive at the correct temperature or fix system temperature inconsistencies.
• If the beer is too cold, acquiring the foam head on the glass becomes challenging. This results in the product having a flat appearance. Beer that has been frozen and then thawed takes on a hazy/cloudy appearance. Assure beer temperature is within the appropriate temperature range.

Pressure

Determine the pressure source for applying to the keg. CO2 is usual for the short kegerator type systems where a gas blend of CO2 and nitrogen allows dispensing over longer distances. The correct amount of these pressure sources is required to prevent undesirable flavor changes and excess foaming.

• The CO2 pressure applied to the keg should be between 12-15 lbs. Typical ales and lagers served at 36-38° F are most stable at these pressures. Use less pressure for lower carbonated beers and closer to 15 lbs. for higher levels. Some highly carbonated products, such as refermenting beers, may require even higher-pressure levels.
• If the system pressure is too low, the beer's carbonation releases while pouring, causing foam.
• The beer's top layer slowly absorbs the CO2 pressure source if it is too high. When this layer arrives at the bottom of the keg, foam (wild beer) appears. Often this condition is referred to as over-carbonation.
• For proper carbonation levels, contact the brewer. Determine the beer temperature and reference a carbonation chart. Dial in the correct CO2 pressure amount to solve these issues.
  
• Due to atmospheric pressure changes at higher elevations, adjust the pressure from the carbonation chart (based on 1-1000’ elevations) one pound for every 2000’ above sea level. If the pressure required for sea level were 14 lbs., it would be 16 lbs for a system located at 4800’.  
  
• For an ale or lager, the typical gas blend ratio should be 70% CO2 / 30% nitrogen, and the pressure between 20-25 lbs. The beer eventually appears flat in the glass if it is too low. Over-carbonation (wild beer) occurs if the pressure is too high. Adjust the pressure to stay within this range.

System Maintenance

Scheduled cleaning of draught beer system components such as the faucet, beer hose, and keg coupler is essential. "Brewery Clean" glassware is critical; otherwise, cloudy beer, off-flavors, and wild/foamy conditions will occur.

• The faucet, beer line, and keg coupler should be cleaned with an appropriate chemical solution every two weeks, and with every keg, change if home dispensing. Seals and O-rings should be inspected and replaced if necessary. Additionally, mandatory processes must be employed to remove the biofilm plaque, which accumulates inside system lines and hardware. If these beer spoilers are allowed to accumulate due to a lack of cleaning, hazy beer, and sour or fruity flavors will result. Eventually, foamy pours will appear. 
• Reference the Brewers Association guidelines. A few minutes spent cleaning on a scheduled two-week basis will significantly add to your draught beer enjoyment! 
• Improper glassware cleaning will cause off-taste complaints and an undesired appearance. The foam head will dissipate rapidly, leaving a flat beer perception, while bubbles will either adhere to the side walls of the filled glass or rise from the bottom. A soapy or chemical off-taste complaint is common.
• Utilize glassware cleaning products designed for beer glasses. Allow glassware to air dry before dispensing. At home, dishwashers are preferable to handwashing with dish soap.