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Old 12-24-2011, 03:15 AM   #1
wmatejka
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So I have used my conical two times now and am pleased with the outcome. However, both times, I have drained my yeast and trub and the airlock, expectedly, takes on negative pressure and even sucks in some oxygen.
My experiences in homebrewing and understanding of simple elements says that CO2 is heavier than Oxygen, so even when O2 is drawn back into the conical, it should rest on top of the CO2 that is already filling the dead space.

Any thoughts on this?

Should I be worried? I mean, I am sure others experience this as well. Just want to see what everyone else thinks.

Thanks,
Wes

 
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Old 12-24-2011, 04:10 AM   #2
strat_thru_marshall
 
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can you attach a quick disconnect to the conical that you can hook CO2 up to? Put 2 psi of pressure on the conical when you're draining it. Thats what I've seen pros do on big conicals.

 
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Old 12-24-2011, 05:29 AM   #3
outside92129
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i was/am nervous too, i've been filling a small bag with co2 and put it on the airlock while i dump. Not sure if i need to, but it's easy and good insurance until i learn otherwise.

 
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Old 12-24-2011, 09:06 AM   #4
frankstoneline
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While CO2 is heavier than O2 these both exist in ambient air, and realistically you will end up with mixing in the head space of your conical. I wouldnt think too much of the amount of oxygen that would be drawn in when you dump your yeast, although if it is a concern purging with CO2 wouldnt be difficult.

 
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Old 12-24-2011, 02:08 PM   #5
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The bag of Co2 trick would be the best bet unless you have a small spare bottle that you can set to a quarter PSI.
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Old 12-24-2011, 05:24 PM   #6
frankstoneline
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Quote:
Originally Posted by Bobby_M View Post
The bag of Co2 trick would be the best bet unless you have a small spare bottle that you can set to a quarter PSI.
You could also acquire a small co2 cartridge bike tire inflator and fashion some sort of device which would allow you to use those disposable co2 cartridges as opposed to needing a tank. I think the low tech method would be to just use a balloon to transfer the co2, though there must be a better way.

 
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Old 12-25-2011, 03:26 AM   #7
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I'm not sure what could be easier than blowing up a bag with CO2. I'm thinking something like a saline drip bag since it's already got a tubing port on it and won't be a contamination risk.
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Old 12-31-2011, 09:50 PM   #8
palmereldritch
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FWIW, the instructions for the Fermenator specifically say "the CO2 from the actively fermenting beer is generally sufficient to purge any ingested air from the tank."

 
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Old 12-31-2011, 11:02 PM   #9
LordUlrich
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To start the comment co2 is heavier than air is a drastic oversimplification of fluid dynamics completely ignoring the concept of diffusion and mixing.
However the process of transferring beer is also a bit more complicated than it seems. While there is a blanket of nearly pure co2 in the conical, when the beer is disturbed co2 will come out of solution pushing the air away from the beer.
In practice any o2 pickup is minimal, how do people with carboys or buckets make good beer if those is a huge issue. At work I just let air make up the volume when transferring, and have a beer 6 months old with no detectable oxidation.
So relax push with co2 or don't worry about it.
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Old 01-01-2012, 05:08 PM   #10
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Quote:
Originally Posted by palmereldritch View Post
FWIW, the instructions for the Fermenator specifically say "the CO2 from the actively fermenting beer is generally sufficient to purge any ingested air from the tank."
That works assuming any draining activity is happening during active fermentation but when you're transferring or dumping yeast, fermentation is generally over. I do think something as simple as tapping on the side is enough to knock a cubic foot of co2 out of solution.
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