Co2 psi techniques - Beer, Wine, Mead, & Cider Brewing Discussion Community.

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New Member
Apr 5, 2013
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So I've been searching around for quite sometime now trying to find different techniques for carbonating seltzer water in a 5gal corny. I've read a bunch of different post from folks about how they carbonate seltzer, how much psi to use, temp and how much line, but I'm still trying to find the most efficient and fastest methods for carbing seltzer.

My technique,

5gal corny keg
fridge temp around 35 to 38 degrees
psi at 35
Set and forget

Usually takes around 7 days to reach the level of carbonation I like (store bought level). This methods has always worked for me. Though the last few times the water hasn't been quite as carbonated as I would have liked. I usually carb 2 kegs at a time and it usually takes about 2 to 3lbs of Co2. Ultimately I would like to save as much Co2 as possible and carb as fast as possible.

Sometimes i forget to purge my kegs after filling up with water which I assume might have some effects? I usually also connect the Co2 up right after filling up the keg with tap water. I assume the temp is around 40 to 50 at this point.

I've also tried the shake method, which doesn't work out to great seeing as I have to balance my 5lb Co2 tank while rolling my keg around on the ground. The time I did try this method my water temp was around 40 degrees and I rolled the keg around for prob 20 min. The carb level was no where near the way I wanted it.

One technique that I've also tried is shaking the keg at the beginning. Basically filling the keg up with cold tap water attaching the Co2 and shaking until I don't hear the gas dissolving any more (couple mins), then leaving it to sit checking it every couple days. This method didn't work any better for me than the set and forget method. Still took around a week for the water to carb.

I tried serving my seltzer a few different ways. Once its ready unhooking the Co2 and connecting 5ft of 3/16" beer line. The pressure from the keg pushes out the seltzer just fine. Sometimes have to reconnect Co2 to add more pressure when the keg gets low. Never had an issue with line being to short, though the seltzer does come out with some force. Could this been causing me to loose Co2 in my seltzer?

Thats the way I normally serve. I've been thinking about trying a few different techniques. Leaving the Co2 connected and serving at 10psi. Leave the Co2 connected and serving at carbing pressure (30 to 35psi) would I need 25 to 30' of 3/16" for this? I'm also going to be purchasing a tap soon to serve my seltzer from. Any recommendations? I love the old soda fountain style taps, but they are a bit pricey.

What do you see wrong with my techniques? What works for you? Any advice is much appreciated! Happy Brewing!!

Action Jackson


Active Member
Sep 17, 2012
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Idaho Falls
Actionj; what my family does is fill a keg with water (and it comes out about 35-40 deg here) hook up the co2 and for the next few hours, shake the keg when we think about it, and usually by the next morning it's carbed enough to drink. I don't have a fridge to keep mine in, but it stays cold where I keep it. As for purging, I think that's something to do with beer, if oxygen gets to the beer, it will cause problems. With water, there's no problems. I guess it's all in what works for you.


Well-Known Member
Jan 25, 2013
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The book Fix the Pumps has pages and pages on this subject. He says purging air is very (in italics) beneficial because air displaces co2 in solution, but more importantly it triggers the premature release of co2 when pressure drops because air releases first and agitates stuff. So not only does he say purge air out from the beginning, but after pressurizing with co2 you can release the pressure to kick air out, then pressurize co2 again, then repeat up to 3 times. Of course that doesn't conserve co2. He notes many other factors besides air and the important temperature, such as no soap residue or things that can nucleate bubbles.