Purging the beer keg in the dispensing line during service

Purging a keg in the dispensing line is a critical task to ensure proper dispensing of the drink and to avoid losses. Purging helps remove gas pockets from the dispensing line, which can negatively affect the pour, causing excessive foam, surging at the tap and a lot of wasted beer. There are cellarbuoys that allow the line to be purged after the keg, preventing the issue from affecting the entire dispensing line up to the tap. Here we show you the steps to correctly purge a keg in the dispensing line.

Step 1: Prepare the equipment before you start purging the dispense line up to the tap; it’s important to have everything you need at hand. We’ll see that the beer stops coming out of the tap either with a burst of foam or gradually if we have a cellarbuoy installed in the line. You should have a container to collect the wasted beer, a keg coupler connected to the keg, an optional cellarbuoy, and any other materials that may be necessary.

Step 2: Change the keg by disconnecting the empty one and reconnecting the beer coupler to a new keg. Open the purge valve on the empty cellarbuoy or open the tap with a container underneath to allow the beer and gas to leave the dispense line. Continue dispensing and purging the line until the beer coming out is clear, continuous and without foam.

Step 3: Make sure to keep the container under the tap until the beer begins to flow continuously. Close the tap and leave the cellarbuoy filled with beer again and the dispense line open once the beer runs clear and without foam; the line is now purged and ready for service.

Step 4: Check the inlet pressure to the keg and the dispensing line once the beer begins to flow continuously. The ideal pressure for dispensing beer is between 1 and 3.5 bar, depending on whether the keg is at room temperature, in a cold room, or is a plastic keg with an inner bag (such as a bag-in-box), like KeyKeg kegs. If the pressure is too high or too low, adjust the pressure on the CO2 gas regulator until you reach the optimal pressure.

Step 5: Taste the beer after purging and adjusting the pressure to check its flavor and quality. If the beer tastes fresh and doesn’t have excessive foam, then the purge has been carried out correctly. If the beer still has a suspicious taste or one that differs from the beer’s original flavor, perform a line cleaning to remove any residue and possible contamination in the dispensing line until the beer has an optimal flavor, just as it left the brewery.

In conclusion, properly purging a beer keg in the dispense line is essential to ensure the beer’s freshness and optimal flavor. Follow these steps to make sure your beer keg is always ready to serve beer with excellent quality at your venue.

Cellarbuoy keg change instruction manual