DIY: Quick Carbonation System
If you keg your home-brew, carbonating it properly is important. Force carbonating your beer the long way (setting your co2 regulator to a specific pressure and letting it sit) is accurate and effective, but ties up equipment and delays drinking pleasure for several days or more, depending on the desired carbonation level, refrigeration space, and volume of beer. The quick and dirty method — crank the pressure and shake/rock/roll the keg — can speed things up a lot, but is inaccurate to say the least. If you want the best of both worlds – speed and accuracy – then a quick carbonation system like this one just might be the answer.
- 1 – diaphragm pump (12v, 4.5 liters per minute) – Amazon
- 1 – ½” x ½” x ½” female NPT stainless steel plumbing tee – SFBC
- 2 – ½” male NPT x 3/8” barb stainless steel pipe fittings – SFBC
- 1 – 2 micron carbonation stone, ½” NPT x ¼” barb, stainless steel – SFBC
- 6 ft – 5/16” thick walled beverage tubing – SFBC (not on the website for some reason)
- 4 ft – 5/16″” gas tubing – SFBC (I had to use 5/16″ because of my regulator outlet size. If you are using 5/16″ as well, clamp it to the carb stone very tightly, because the barb on it is only 1/4″. If you have an MFL thread on your regulator, use 1/4″ tubing for a better fit. If you don’t know what I’m talking about, just bring your regulator to your homebrew shop and get them to figure it out)
- 8 – butterfly gear clamps – SFBC
- 1 – gas ball-lock or pin-lock connector (MFL) – SFBC Ball lock / Pin lock
- 1 – liquid ball-lock or pin-lock connector (MFL) – SFBC Ball lock / Pin lock
- 2- 3/8″ MFL swivel nuts – SFBC
- 1- 6-12v power supply (or whatever voltage your particular pump requires, KW Surplus)
- 1-power supply connector (KW surplus)
- 1- small project box (KW surplus)
- 1- on/off switch (KW surplus)
- scrap piece of plywood
- wood screws
- Teflon tape
- Electrical tape
The power supply I chose is from a laptop computer. The pump should operate well enough with a 6v power supply as well – it pumps like a fire hose the way it is now. The power supply connector was chosen to match the output of the power supply so that it can be disconnected for storage. The positive (red) wire from the connector is soldered to one side of the switch, and the positive (red) wire from the pump goes to the other side. The ground wires (black and yellow) are soldered to each other and taped. This style pump can be run with either wire connected to power. The switch is mounted to the black project box and all connections are located inside the box (see picture). The box and pump are screwed to the plywood using round socket head particle board screws.
Carbonation Stone Assembly
The 1/2″ plumbing tee has 1/2″ NPT x 3/8″ barbed fittings threaded into the left and top ports (see image below) and a 1/2″ NPT x 1/4″ barbed carbonation stone threaded into the right port. The teflon tape is probably not really necessary on the tapered pipe threads, but I used it to give some cheap extra insurance against leaks.
The inlet of the pump (left port in the action shot below) is connected to a 5/16″ thick walled beverage line with a 3/8″ MFL swivel nut on the other end to connect to the ball lock or pin lock connector. I used tubing that was 1/16″ smaller than the barbed ports and fittings to ensure a very tight fit and prevent leaks and air intrusion- the tubing is fairly easy to get on if you run it under some hot water for a few seconds. The outlet of the pump (right port in the image) is connected to the inlet of the carbonation tee assembly with a short piece of the same tubing, and the outlet of the tee (upper port in the image) also has a 5/16″ thick walled beverage line with a 3/8″ MFL swivel nut. The carbonation stone is connected to the co2 tank with gas tubing. I clamped everything with butterfly gear clamps for ease of disassembly and because they are easier to tighten/loosen in the event of a problem during operation, when I wouldn’t want to be scrambling for a screwdriver.
First, sanitize the system by pumping sanitizer through all of the lines. The inlet, outlet and gas lines (without keg connectors or co2 regulator connected) should all be submerged in a bucket of sanitizer, and the pump turned on. Once sanitizer has run through the outlet hose for sufficient time the outlet hose is crimped shut to force sanitizer through the carbonation stone. Then remove the inlet hose from the sanitizer to clear out all of the sanitizer, once again restricting the outlet hose to force sanitizer out of the carbonation stone and gas hose. With the pump turned off, connect the gas line to the co2 regulator and blow co2 through the lines to purge them of air. Connect the black ball or pin lock connector to the inlet hose and connect it to the keg after depressurizing the keg. Pump beer through the lines before connecting the grey ball or pin lock connector to the outlet hose and connecting it to the keg as well.
Set the co2 regulator a couple of psi higher than the pressure indicated on a carbonation chart (available online, google it). If you are aiming for a very specific carbonation level the exact pressure will take a little tweaking and tasting – it is quick and easy to raise the level of carbonation if desired. It is not so easy to lower the carbonation level if you overshoot it, so start with 2 psi above the pressure shown on the chart and go from there until you are happy with the carbonation level. Once the pressure is set and all hoses are connected, start the pump. You should see the beer in the saturation tube (the one exiting the carbonation tee and going back to the gas port on the keg) turn whiter and bubbly/foamy as shown in the image above. Once the beer in this line looks the same as the beer in the inlet tube from the keg to the pump, carbonation is complete. I find it takes around twenty minutes with the small keg shown above, but I normally leave it for thirty minutes just to be sure. The amount of time it takes will vary based on various factors such as the size of the holes in your carb stone, the desired carbonation level, the temperature, the flow rate of your pump, voltage supply etc. It only takes a few minutes to settle enough to start pouring (as long as it is cold). It will take a bit longer to settle enough for bottling from the keg.
So far, everything works as I hoped. I have seen and used a couple different versions of a commercial in-line carbonation system, and this diy version seems to work just as well. It carbonates as quickly as the commercial examples I have used, uses better quality tubing than is supplied with them, and costs a fraction of the price (mine ended up in the $120 range, because I bought all new hoses, keg connection fittings, etc; this cost could be lowered further if you have some bits and pieces lying around). I have also found the pump and switch assembly useful for transferring tasks (such as transferring from a fermenter to a purged keg) and the pump and carbonation stone assembly (or the carb stone assembly alone) could easily be adapted for in-line oxygenation of wort.