Knowing how to change a beer keg is useful in the bar and nightclub industry. The downtime resulting from the inconvenience of a bartender abandoning his post to replace an empty keg can hurt customer impressions. The last thing you want is a mob of thirsty angry customers.
This article aims to teach you how to change a beer keg. We’ll proceed step-by-step, explaining the importance of each action. Please put on your dust coat, and let’s go to work.
Step 1: Confirm That Your Keg is Empty
A dry tap doesn’t necessarily mean that the keg is empty. Beer flow may be interrupted by an empty gas tank or an empty keg.
Below are ways to diagnose each cause of flow interruption:
An Empty Gas Tank
Most modern draught beer systems operate with this principle: using a gas to push out beer from a keg. Most draught systems use carbon dioxide, but certain beers (such as dry stouts) require nitrogen gas.
Without pressurized gas, beer cannot flow out of the keg and into the beer tower. How can you tell when you run out of gas?
Check the pressure gauge at room temperature. If the needle is in the red at room temperature, you have an empty tank. Another indicator is the tank’s weight. An empty tank will be lighter than a full cylinder.
An Empty Keg
The keg is the source of beer in a draught system. You can only expect beer to flow through your taps when there’s beer in the keg. How do you tell whether your keg is empty or not?
In long-draw draft systems, you’ll notice that the cellar buoy or FOB detector is empty. The foam on beer (FOB) detector is a device that cuts off beer flow when the keg is running out. Without the FOB detector, empty kegs would continue serving foam and gas.
Check out our article on why beer foams to learn about frothing in beers.
You can tell the beer level on a plastic keg by looking through the translucent barrel. Bringing out a plastic keg from a refrigerated environment can also reveal a condensation line that indicates the beer level. For steel kegs, inspection is more complex.
Lifting and swishing steel kegs can tell you how much beer is in the container. An empty keg will be light and quiet.
After confirming that your keg is empty, proceed to the next step.
Step 2: Turn Off Your Gas Supply
Most draught systems use carbon dioxide or nitrogen gas to force the beer out of the keg and into the beer line. Before replacing the keg, you must deactivate the gas line. Failure to turn off your gas will lead to leakage and wastage.
Depending on the complexity of your system, the gas supply valve may be in different locations. Long-draw systems have independent gas valves, while direct-draw draught systems rely on the gas tank’s tap.
Find the shut-off point for your draught system and turn off the gas.
Step 3: Disengage the Keg Coupler
Also known as the keg tap, the coupler connects the gas and beer lines to the keg. It allows compressed nitrogen or carbon dioxide gas into the keg and extracts beer from the barrel. Different beer styles use different kinds of kegs, requiring different couplers.
Below are the seven types of keg couplers:
- A System Couplers
- D System Couplers
- G System Couplers
- M System Couplers
- S System Couplers
- U System Couplers
- K System Couplers
A System Couplers
Also known as the German Slider Coupler, these keg taps work with German brews like Paulaner, Warsteiner, and Sparten.
M System Couplers
This keg tap is compatible with various German beers, including Aventinus, Einbecker, Schneider, and Veltins. Since A and M System couplers work with German kegs, their locking mechanisms are similar.
To disengage M and A system couplers, unlock the handle and slide it out the keg’s lugs.
D System Couplers
Also known as Sankey keg couplers, these keg taps work with North American beers. Most craft beer kegs are D-system-compatible.
S System Couplers
Also known as European Sankey Couplers, S System keg taps work with European imports like Amstell, Becks, and Heineken. Like the D system coupler, S system keg taps twist into place before locking onto the keg. However, the US Sankey coupler has a smaller dip compared to European equivalents.
To disengage D and S System couples, unlock the handle and twist it anti-clockwise.
G System Couplers
These keg taps are compatible with UK beer brands like Boddington’s and Bass.
U System Couplers
Like G System couplers, U System keg taps are compatible with kegs from the UK. They serve Harp, Guinness, Kilkenny, and other beers from the United Kingdom.
K System Couplers
Also known as KeyKeg couplers, K System keg taps are designed for use with single-use plastic kegs. These kegs are quickly gaining popularity among select US wineries and European breweries.
Safety Precaution: Never place your face directly over the coupler when disengaging the coupler. Kegs are pressurized containers that may eject couplers with tremendous force.
Step 4: Attach the New Keg
Now that the coupler is disengaged, find a replacement keg. Always use the “First In, First Out” principle when finding your replacement keg. This strategy ensures that you sell the older kegs first and that your inventory remains fresh.
Double-check the full keg before tapping to ensure the beer is within the best-before date.
Once you settle on a specific keg, break open the security seal, then engage the coupler. For Sankey (D and S System) couplers, insert the keg tap into the keg well, twist, then pull down the lever to lock. For German Slider (A and M System) couplers, slide in the keg tap before pulling down the lever.
Improper coupler attachment disrupts beer flow. Ensure the keg tap fits securely in the grooves of the keg.
Note: The coupler could be damaged if you’re having trouble fitting it. Inspect the grooves and if you notice any bending or chipping, consult a qualified technician or replace it.
Step 5: Vent the FOB Detector
Once the coupler is fitted securely, turn on your gas supply. Check the pressure reading and ensure that it’s within the normal range. If your draught system has a FOB detector attached, vent out the gas to draw in the new beer batch.
Once the cellar buoy is full, release the FOB float to allow the beer to flow to the beer tower.
Step 6: Drain the Old Beer and Serve the New Batch
Depending on the length of your beer line, you may have a pint or two of the old beer stuck in the pipes. Open the beer tower faucet and let out the old beer. Once the old batch is out, you can serve your customers some fresh beer.
When you are running or working in any bar or restaurant, beer and how it’s delivered is important. Changing a beer keg is a critical part of draught system maintenance. Knowing how to change a beer keg is a useful skill that can make you attractive to potential employers.
Which aspect of draught system maintenance should we tackle next? Let us know in the comment section below.
Sandra B. King is a wife and mother of two. The marketing genius is also a beer enthusiast. Even though she doesn’t brew beers, she can whip up a mean content marketing strategy.