Maintaining Your Draft Beer For Better Profits.
Draft beer is a sensitive product and takes certain parameters to be just right in order to dispense properly: Temperature, Pressure, Appropriate Propellant, and a Good Beer Dispensing System Design are a start to the necessary requirements for proper dispensing. The easiest way to determine if you are losing draft beer because your system is not operating efficiently is by tightly tracking usage and waste through your beverage management system.
To do this accurately, you should be weighing your tapped kegs with a keg scale to keep track of usage as accurately as possible. Once you start weighing your kegs, if large product losses are found by comparing your register sales to actual usage, first look at the possibility of a potential theft problem. If you find that theft isn't the main issue for the product loss then it's time to look at other possible causes.
Let's start at the basics and diagnose why you might be having draft beer losses:
1) Does the serving temperature correspond to the brewers norms?
North America: 38F(3.3C) & 42 F(5.5C)
Pour a glass and insert a thermometer immediately in the freshly poured beer. If the temperature in the glass is outside these norms, it is quite possible that your refrigeration system is defective or needs adjustment. Too high a temperature will increase the risk of excessive foaming. If the beer is too cold, the beer is not foamy enough and bartenders usually serve more in each glass. In either case, you should be concerned that the pour cost will probably be too high.
2) Is the flow rate between 2.5 and 3.5 l/min (Approx 2 oz/sec)?
If the flow rate is too slow, it is probably due to a lack of pressure in the system. The C02 gas can separate from the beer while in the line causing the beer to foam at the tap. The color of the beer will change a few seconds after the tap is opened, passing from a clear and golden color to white.
3) Is the beer flat or over carbonated?
Check the propellant! Any beer system with a distance between the kegs and the faucet greater than 10 feet (3 meters) should be pressurized using a mixture of air or nitrogen (70 %) and CO2 (30 %). Straight CO2 can be used for direct draw systems and very short runs (less than 10 feet or 3 M). Clean straight air can be used if the sales volume per day is very high. Otherwise, it will either contaminate the beer (think of where the air is pumped from) or it will make the beer flat. The wrong choice of propellant will either make the beer foam, make it flat, and/or change the taste. In either case you will be wasting product thus increasing your pour cost.
Causes and Corrections:
Improper holding of the glass - Glass must be held at a proper distance from the faucet - too close and there will be no head - too far and it will be all foam.
Poor pouring habits - Faucets should be opened fully and quickly. A faucet that is not opening quickly and fully will cause beer to foam.
Yeast build up in faucet - Clean faucet daily with a good faucet brush. Scour all internal parts at least once a week and clean with BLC. Keep faucet cold to prevent yeast growth.
Kinks, dents, twists in the beer line - Correct lay of the beer line is necessary.
Sag or trap in the beer line - Since line lengths must be maintained route the line so as it is always leading up from the keg connector to the faucet. Spirals are a good way of using up extra line inside the beer system.
Beer is too warm - The temperature at the faucet must be as cold as the keg. Beer line must be kept refrigerated. Insulation is not refrigeration. Keep lines away from hot spots like heater pipes, hot water pipes and steam pipes.
No cold storage space for beer - Keep all kegs of beer refrigerated at all times. Never allow the keg to get above 40°F.
Too much pressure - Pressure should be maintained such that the beer will fill a 10 ounce glass in 4 seconds. Check for proper regulator function.
Excess CO2 - Adjust the CO2 pressure as low as possible to maintain the proper beer flow. No more than 18 psi should be applied to the keg.
Not enough pressure - Check for defective air vents and restrictions caused by dents. kinks and contamination in the pressure line and valves. Always turn on the pressure before drawing the beer.
Old beer - Rotate stock and store beer at 40°F. all the time to prevent secondary fermentation.