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Opinions wanted: Capturing CO2

Posted: Mon May 13, 2019 2:15 pm
by Kealia
I've got an aggressive fermentation going and I had planned to 'harvest' the CO2 from this batch but forgot to set it up.

My plan was to hook up to the gas in on my 5G keg and use the fermentation co2 to push out sanitizer from the keg, leaving me with a fully purged 5G keg when I'm ready to transfer to it.

At this point, I could hook up the gas in, but don't have an extra liquid out to hook that piece up. I *could* just open the PRV to let it gas out that way, but not sure how much CO2 would be captured if I did that.

I know it couldn't HURT, just wondering if it would be worth the effort.

Any thoughts here?

Re: Opinions wanted: Capturing CO2

Posted: Mon May 13, 2019 5:17 pm
by Kealia
UPDATE: I figured that I likely missed the majority of the strongest fermentation but I hooked it ALL up to see what would happen. I gave it two hours and then because I'm impatient pulled it off and put the blowoff back into the jar of sanitizer. I then just hooked up my extra CO2 tank to the 5G keg and pushed the sanitizer out so it's sanitized, purged and ready to go.

My thinking was that I may not generate enough pressure at this point to push the sanitizer via the blowoff and didn't want to end up pressurizing my SS Brewbucket to any degree. Next time.....

But I'll leave this here for anybody that may want to do this set up in the future - which is not my own idea, but borrowed from multiple other places.

Re: Opinions wanted: Capturing CO2

Posted: Mon May 13, 2019 9:08 pm
by D_Rabbit
Not sure this would work 100% but based on my research on pressurized fermentation you might need a spundling valve set up to the gas port to release the extra pressure that builds up. You could set it to like 5 psi and if it gets to that level it would act as a pressure release valve automatically.


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Re: Opinions wanted: Capturing CO2

Posted: Tue May 14, 2019 11:25 am
by Kealia
I actually didn't want a pressurized fermentation. I was going to let all of the CO2 escape into the corny keg and push out the Starsan. I just realized that I set up the gear too late and that I likely wasn't going to get enough pressure to push it out. Next time, though!

Re: Opinions wanted: Capturing CO2

Posted: Tue May 14, 2019 12:12 pm
by D_Rabbit
I understand that but you still want something to keep the CO2 in the keg once primary dies down and the liquid is out. The spundling valve can let you set the PSI in the keg to like 2 and push it out after that. It would allow to keep pressure on the keg even after the liquid is gone.


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Re: Opinions wanted: Capturing CO2

Posted: Tue May 14, 2019 1:23 pm
by Kealia
Ah, I see what you are saying.
Since I won't do this all the time - as sometimes my blowoff tube actually does carry krausen blowing off, I'll likely give it a shot without the spunding valve next time. Once it stops blowing out and the Starsan is pushed out I can hit the keg with a quick shot from the CO2 tank to give it a bit of pressure.

I appreciate the input.