Do you have a "Beer Chilled Draught Dispensing System"? Hopefully not! Because if you do, it’s highly likely that you’re not using that drip tray under the faucets as it was intended. In fact, we don’t call them drains… This method of dispensing beer from a keg is referred to as "The Most Expensive Draught System on the Face of the Earth". Unfortunately, the beer is being used to overcome inadequate system designs. The result is higher operating costs, lower keg yield, and compromised quality because the beer’s carbonation is lowered.
Often, in any type of draft beer system, the temperature of the beer in a line fluctuates and increases as it moves past the keg towards the faucet. This can be due to beer lines that have been routed near heat sources and/or inefficient system cooling between the keg and faucet. Eventually, cold beer that exits the keg will flow through these problem areas, eliminating the foam-causing heat. Now that’s an expensive way of chilling beer!
At home in your kegerator – or within retail systems at bars, restaurants, venues, etc. – the beer temperature must be maintained all the way to the faucet, or you’ll end up with foam and wasted product.
Why the foam? One very important aspect of beer: it has gas. Fermentation, to be exact, where in the brewing process yeast is added to the unfermented beer (wort) and thus devours the sugars. This produces alcohol and carbon dioxide (CO2) gas. Remember your high school science class way back when? What happens to a gas when it is heated? You’re right, it expands.
This is what happens to the CO2 in beer when it is subjected to an area in any draught system where the temperature is too warm: the gas expands and breaks out of the beer, resulting in an accumulation of foam. Behind the faucet is a very common area for this to occur. The collection of foam will spill out of the faucet, causing difficulties in dispensing. That foam that goes down the drip tray mostly consists of the gas that should have been in the beer. End result: flat beer!
If you begin with foam while pouring beer in a glass, and then attempt to follow with clear beer, you’ll breed more foam. You’ll know when bartenders are experiencing this difficulty when you see them continually tipping the glass as they dispense with foam rolling out and pouring into the “drip tray”.
The most successful dispensing system is one that can maintain temperature at the keg, and all the way to the faucet.
Kegerators should have some method of moving the cold air into its tower. Air cooled remote systems at retail outlets, notoriously labeled “Beer Chilled Systems”, are most efficient if the keg cooler door is kept closed and there is an efficient air flow to the faucets and then back to the cooler. Glycol remote systems are by far the most successful at maintaining temperature, although issues arise when the lines are routed above kitchen hoods and when the power pack is not maintained or located in an area where it cannot operate efficiently.
The CO2 in beer should always be ‘Top of Mind’ while designing, installing and dispensing beer from a keg. Control system temperature, and you’ll control the beer’s CO2. Controlling the CO2 will allow you to take full advantage of draft beer’s profit potential and fresh taste!