CO2 "Blanket" in secondary

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jrnyenhuis

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I'm not sure how many people this would apply to, but I figure a lot of people like me are relatively new to the hobby and on a budget, so don't see buying much equipment anytime soon.

Anyway, I recently picked up a 6 gallon carboy at a resale shop (definitely my best find ever at Goodwill!) as a companion to the 6.5 gallon one I had already, and I wanted to try a secondary fermentation step - mostly for kicks. Since my current batch is 5.5 gallons, there's quite a bit of headspace, which I didn't really think about ahead of time. It's already in there, so oxygen is unfortunately probably already doing a bit of work on it, but oh well.

I've been thinking about next time around perhaps trying to "fabricate" a CO2 blanket for the secondary, and different ways of doing that. My options seem to be: a) buy a smaller carboy specifically for secondary, or smaller primary batches; b) buy a compressed CO2 tank, which would work nicely with a keg system down the road - not really there financially, though; or c) make my own CO2 and get it into the carboy somehow so that it can settle under the oxygen layer.

I'm liking c) until my discretionary spending can widen up a bit. There's a few household-ingredient reactions I'm looking at to get the CO2: so far I can think of Alka-Seltzer tablets in water or vinegar and baking soda (very similar reactions, I know). Question: are there any more efficient CO2-producing reactions I can get with cheap, commonly-available ingredients? For getting the gas into the carboy, I can see using a dish in the large funnel/strainer set I already have, with a cover on top and positioned over the carboy opening. Also, if I can get a pretty good reaction going in a small-mouth container (think small Erlenmeyer flask), I could fit a balloon over it to trap the gas, a la middle school science project; it would be pretty simple thereafter to direct the gas into the carboy.

Anyway, even if all this turns out not to be strictly necessary or efficient, it still sounds like fun and I think I'm going to mess around with it. Any suggestions/admonishments are welcome!
 

ArcaneXor

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Eat beans and fart into the carboy. The methane and hydrogen sulfide will take care of your beer!
 

RoadKing

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Go for the co2. I have a 20 lb. tank and I use it for everything... Blowing out computers etc. also you'll be ready for kegging when your ready.
 

RDWHAHB

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I think this is silly, but that's not what you asked. So to answer your question:
Dry Ice is CO2. Just put that in a bottle/flask/whatever and pipe the gas into the carboy.
 
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jrnyenhuis

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It is silly, but it's also... interactive. So :p

I just remembered, I could also add ascorbic acid to eat up some of the O2.
 
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jrnyenhuis

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What would happen if I just sucked most of the air out of the carboy and capped it, letting the yeast fill it back up with CO2 as they saw fit?
 

Navy_Chief

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Rig a blowoff tube from primary to a jar equipped with a cap with two tubes; one for the blowoff, and one for a secondary tube going to the second carboy. the CO2 produced from primary will fill the second carboy with CO2 you are already producing without any of the mess from the blowoff tube.
 

tagz

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Rig a blowoff tube from primary to a jar equipped with a cap with two tubes; one for the blowoff, and one for a secondary tube going to the second carboy. the CO2 produced from primary will fill the second carboy with CO2 you are already producing without any of the mess from the blowoff tube.
That's kind of a cool idea.
 

aomagman78

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You can also put a stopper+tubing into a gatorade bottle with the other end in the secondary, freely no stopper so O2 can leave. Then fill the gatorade with vinegar and baking soda (careful not to overflow gatorade). This will pump PLENTY of CO2 to evacuate your secondary container if you use enough. And it's cheap.
 

HHP

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What would happen if I just sucked most of the air out of the carboy and capped it, letting the yeast fill it back up with CO2 as they saw fit?
This is a VERY bad idea. Pathogens are not supposed to be able to grow in beer, due to the pH and alcohol content ... but many very bad ones grow very well in negative pressure situations (botulism comes to mind). Especially with the risk that there will be no yeast activity to produce co2, there might be a negative pressure situation for a long time.

Just dont secondary ;)
 
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jrnyenhuis

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You can also put a stopper+tubing into a gatorade bottle with the other end in the secondary, freely no stopper so O2 can leave. Then fill the gatorade with vinegar and baking soda (careful not to overflow gatorade). This will pump PLENTY of CO2 to evacuate your secondary container if you use enough. And it's cheap.
I like this setup. Although I'd want to run another hose off my carboy cap and into a bucket of starsan solution; leaving it open would give me the heebie-jeebies.

Speaking of heebie-jeebies, botulism! Hadn't thought of that. OK, will not try that approach.
 
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