# Capturing Co2 From Fermentation



## andreic (23/5/07)

Hi,

I was chatting with a fellow brewer at work the other day. His daughter told him each beer he brews releases 300L CO2 into the atmosphere (some kind of school science thing). So I did some basic calculations myself based on OG, FG and came up with 250-300L for an average 20L batch (same result, different calculation).

So fellow brewer starts speculating... CO2 is expensive... what if you captured this CO2 and used it to carbonate your kegs? How the hell would you do that? I said.... google is your friend:

Capturing CO2

Has anyone had a go at this? Looks like a fun little experiment / project...

cheers,

Andrei


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## pint of lager (24/5/07)

There is a retired engineer in town who has succeeded in capturing his CO2 and reusing it to carbonate kegs. I don't think he is on the web so you won't see his system. From chatting with him, he has spent many happy hours tinkering with it.

One big hurdle you have to get past is scrubbing the CO2. During fermentation, there are lots of bye products given off. Just ask the airlock sniffers. You do not want these back in your finished beer.

So it is possible, but do you have the time, knowledge and equipment to succeed?


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## Stuster (24/5/07)

If you have a lot of spare reading time  this thread might help you. Apparently, Oldfart put together a system for doing it. Not sure exactly as I gave up reading the thread after the 12th page.


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## Jye (24/5/07)

Hey andreic,

Check this out.

I haven't read it but it should contain some answers.

Jye

Edit - to quick Stuster


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## Stuster (24/5/07)

And neither of us have read it. :lol:


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## Cortez The Killer (24/5/07)

Sounds like a good read


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## andreic (24/5/07)

Jye said:


> Hey andreic,
> 
> Check this out.
> 
> I haven't read it but it should contain some answers.



My god :huh: what a thread... I read the first 6 pages, flicked through another 5 or so quickly and gave up (it is a fairly entertaining read though). Never did find out how oldfart went with his Co2 recapture and carbonation...

I thought this might be an interesting home project for someone... but not me! I never really thought seriously about doing it myself. I will try and con my fellow brewer at work to give it a go


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## Whistlingjack (25/5/07)

I can see one major problem. Volatile gases.

Yeast metabolises the dimethylsulphide precursor into free DMS which is evaporated as gas. Also, there are lager yeasts which produce hydrogen sulphide. 

Unless you want your finished beer to taste of rotten eggs or cabbage, then you have to be able to clean the sulphides from the CO2.

There are other volatile flavour compounds that could be trapped also.

Just my thoughts.

WJ

Edit: Oops, POL mentioned this above. Should read the whole thread first.


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## oldbugman (25/5/07)

co2 is expensive?!


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## Andyd (25/5/07)

I think this is probably more a reaction to greenhouse gasses than it is about the cost of the gas...

I'll keep using gas for now - I don't have beer engines to dispense.


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