Originally Posted by Yuri_Rage
While the idea is admirable, it's likely not cost efficient at all.
To make 1/2 lb of CO2 from table sugar and bread yeast, it will take about 1 lb of sugar and a packet of yeast, at a cost of $1 to $2 ($2 to $4 per pound of CO2).
It only costs about $10 to fill a 5 lb cylinder.
Originally Posted by ob111
see this is fun
Please keep us informed. This is very interesting. Realizing that 3/4 cup of sugar is enough to carbonate 5 G of beer, why not produce small amounts this way?
I agree with Yuri_Rage that this isn't practical for full-time keggers, but for people who just want a source of CO2 for occasional use (carb up a 2L bottle with a carb-cap), it might make perfect sense.
I just spent $36 for a 20 oz paintball tank and a remote so I could hook it up to my regulator (another ~ $35?). Then I'll spend ~ $4 for a fill. You would probably still want a secondary regulator (but you could get away w/o one, by opening a valve, monitoring pressure, then closing), but at least there is no super-high pressure or special fittings required. Regular hardware store stuff should do. Be good to have a ~60PSI safety valve to blow off excess pressure. And you might want a carbon filter inline?
Tire-stem carb caps are easy and cheap and you can clamp a hose over them (remove the valve for this application). I could see connecting up a few 2L bottles as the sources, put a cheap pinch clamp on each, and you could disconnect them one at a time to dump the contents (leaving some yeast behind) and just add more sugar & water. Wait till it displaces the O2, then reattach and open the clamp when pressure builds.
I guess my big question is, does that 3/4C of sugar in one 2L bottle really produce that big of a store
of CO2? When I prime/carb my beer, the liquid is absorbing the CO2. I'm not sure that airspace in the bottles would hold so much.
Oh, and here is an interesting link: