How to Carbonate Beer in a Keg
This guide to carbonating beer in a keg shows you a basic procedure for carbonating and serving beer from post-mix soft drink kegs. Draught beer is the dream of many home brewers who want to serve their beer the way pubs do, so let’s get this done!
How to carbonate beer in a keg
- Sanitise your keg by filling it with the same type of sanitising mix you use for your beer fermenter.
TAB TIP: We use and recommend peracetic acid, OxiClean or hydrogen peroxide in diluted solution. Replace the lid and allow the keg to sit for 20-30 minutes. Don’t leave your keg for longer than this.
- Drain the keg and rinse it thoroughly.
- Purge the keg of all its air by sealing the lid and connecting the gas line from the gas cylinder to the gas inlet on the keg. Turn the gas bottle on and set the pressure to 100 kPa (15 psi). Allow the gas to flow for 30 seconds and then vent the keg by opening the safety valve to release all the pressure. Do this 3 times to ensure all the air is removed from the keg.
- Release all the pressure via the valve and open the lid of the keg. Don’t worry that the gas will escape, as enough will remain because it is heavier than air.
- Fill the keg from your fermenter using the PVC tubing, taking care not to splash the beer, as this will also cause oxidation. Fill to within 50-75mm of the top of the keg. Replace the lid on the keg.
- Connect the gas line to the gas valve on the keg and blow out any remaining air that may still be in the keg. Close the safety valve and pressurise the keg for 10 seconds.
- The length of the hose between your regulator and the keg may need to vary to ensure perfect beer pouring, free from foaming. We suggest:
| If 4 mm ID hose | 1.5 m hose each end |
| If 5 mm ID hose | 3 m hose each end |
| If 6 mm ID hose | 4.5 m hose each end |
- Chill your keg in the fridge to 2°C to 4°C. This will normally take overnight.
- Connect the black liquid disconnect to the gas line from the bottle. Turn on the gas and make sure the gauge is still set to 100 kPa. Leaving this connected, you can then dissolve the gas a lot faster by rocking the keg back and forth.
TAB TIP: Rocking up to 100 times is a pretty good way to get the gas to dissolve in the beer. This might sound like a lot of work, but if you just sit yourself on a chair it will be quite easy!
- Allow the keg to sit in the fridge for 24 hours and repeat this process. This allows plenty of time for the first lot of gas to dissolve into the beer.
- Repeat steps 8 and 9 over the course of 3-4 days. Don’t be concerned about over-gassing the beer, as the pressure set on the regulator will ensure this doesn’t occur.
Dispensing the beer
It’s time to impress all your family and friends! The easiest way to dispense the beer from the keg is to first turn on the gas and make sure the gauge is still set to 100 kPa. Then connect the gas line, with a white gas disconnect attached, to the gas plug on the keg. This is how pubs dispense their draught beer. This pressure will ensure a smooth, easy pour and no carbonation will be lost. It is extremely important to note that the beer lines have to be 4mm in diameter and 2.4m long.
If you try this technique, don't forget to tag us on our socials @artisans.bottega. Let us know what you think of it! We love getting in touch with our TAB family!
