How Much Air Space In The Fermenter?

[pablo_h]

Mustard gas was actually distributed as an aerosol, Wiki Mustard gas link which behaves differently to a gas.

Your refridgerant is a very large molecule, and may have a larger concentration in some spots, but it will diffuse into the air.

Carbon dioxide doesn't form a protective layer over the top of your beer. The air in the headspace of the fermenter is purged of oxygen and any other gas as your fermenting wort produces carbon dioxide. The headpspace is about 7 litres, there is about 120 litres of carbon dioxide produced during fermentation. Please don't go sniffing in the fermenter, carbon dioxide at 5% concentration is deadly.

Aerosol was the delivery method, it has nothing to do with the gas itself. If you read the wiki link you read that it "persisted" in the area for days, ie it didn't wiz around, it stayed where it was delivered for a while. Everything diffuses after a while, refrigerant, mustard gas, co2 etc, but thats because of winds, air pressures, temperature variations carry it, not because of the gases' natural tendancy.

I don't understand the people that say "there is no co2 layer over fermenting beer", but at the same time acknowledge that the yeast continously produces co2 during fementation, so there is nothing above the wort except co2. What is the difference between saying there is a layer, and saying that the fermenter is full of co2 and leaving at that as you do?