I am fairly new to kegging my homebrew. I have successfully used the "Saturation Over Time" method and was wondering if I could speed it up a bit by injecting gas through the draw line rather than the gas line since it would be injected at the bottom of the draw tube rather than on the surface.

Does this approach make any sense?


Injecting gas into the beer out line makes little difference - the size of the bubbles are not small enough to dissolve any significant amount of gas, so they just float to the top and become part of the headspace just as if you'd used the gas in line.

One way to speed up carbonation is to first chill the keg to 41F/5C or cooler, and set the CO2 regulator to 30psi. Connect the gas, and roll the keg back and forth on it's side for a minute. Then disconnect the gas and continue rocking for a further minute or two. The cold beer combined with the rocking motion under fairly high pressure gets the carbon dioxide into solution much quicker. The second rocking without gas helps equalize the pressure. You can then dial the regulator to the target PSI and continue rocking. You stop when you don't hear any more gas entering the keg, usually in just a few minutes.

Leave the keg for a couple of hours and then it's ready for serving.

One downside to this is that you have to either drink the beer quickly (within a week or two max) or take steps to purge the keg of oxygen. The shaking will dissolve any oxygen in the keg into the beer cause it to stale quicker. But it's a winner if you need to carb in a hurry and are sure the beer will be consumed quickly (e.g. a party.)

I've got 4 kegs ready for a party this weekend that I'm carbing up like this.

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    Why not burp the keg by pulling the pressure release valve a few times while at 30PSI to bleed out any oxygen, before rocking it back and forth? Also, this quick method also opens one up to easily over-carbonating their keg, which is time-consuming and annoying to try and level out after the fact. – Scott Jul 10 '13 at 23:17
  • You can purge by filling and burping the keg but it never removes all the oxygen (although that's the way most homebrewers purge their kegs.) – mdma Jul 10 '13 at 23:24
  • That's interesting, First couple kegs I did were definitely overcarbed this way, but that's also because I didn't do as methodically as you (I know, amateur of me =P). Get the PSI to level out afterwards, even if emptying the CO2 near entirely out of the keg still took days to level out after that. – Scott Jul 10 '13 at 23:27
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    I've not overcarbed using this method - and you can tell it's not overcarbed because when you reconnect the CO2 at the desired pressure CO2 is still flowing. If you're worried about overcarbing then just leave the regulator at the target pressure from the start and just keep rocking until the co2 stops flowing - it will just take longer and your arms/legs will ache! If you do start with 30psi and by some bad luck you did overcarb, you just have to rock the keg and burp it a few times to reduce the pressure. – mdma Jul 10 '13 at 23:27
  • Scott, did you time how long you shook the keg for when you overcarbed? – mdma Jul 10 '13 at 23:31

You can also carbonate faster using a carbonation stone. You can buy one ready made online, or make one yourself, or attach a piece of beer line tubing to the gas in tube with a clamp and attach a carbonation stone to the other end, again with a clamp. I like using a plastic clamp for the end with the stone since it's sitting in the beer. Sanitize everything of course. I did this and it works well, you can carbonate in 24 hours without needing to crank the pressure up past the recommended amount (12-15psi). Soak the stone in sanitizer or boil it between uses.


While it seems as if that would speed things up, it really doesn't. I've tried carbing through both the gas in and beer out tubes and found no difference in the rate of CO2 absorption. OTOH, there's nothing wrong with carbing through the beer out, so feel try it each way and draw your own conclusion.

  • Would it more sense to use a diffusion stone? – Andre Jul 10 '13 at 16:30
  • It might, but I have no personal experience with that. – Denny Conn Jul 10 '13 at 19:04

I'm assuming in my answer that by using the slow method of carbonation, that you hook up the gas line to your keg while it's chilled and let it sit for a week, gauging how much PSI you feed in based off something like this chart. If I am correct in my assumption, there is a method that I've found is more timely. Not necessarily as quick as mdma's (which I've done quite a bit as well), but it's safer in that you have time to catch any chance of over-carbonation, rather than doing it all in 5 minutes, crossing your fingers and hoping it won't pour nothing but foam. Take your keg, chill it to 43F/5C, and hook up your CO2 tank at 30PSI. Let it sit on that PSI, at that temperature for 32-48 hours. Take samples at 24, 32, and if need be, 48 hours. It'll gush like crazy at that PSI (you only need a sip), so let the head settle, then sip it to get the mouth feel. If it is flat (don't let the head fool you, the body can be entirely different), let it sit another 12 hours. It's rare that it'll get to 48 hours before it's carbonated. Once you're satisfied, dial the pressure back to serving pressure, let off the excess gas, and you're good!

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