Originally Posted by atreid
I disagree about oxydation... CO2 is heavier than O2 and contrary to a sealed bottle, O2 will get pushed out through the bubbler. So the whole oxydation deal is more about the transfer itself, not the carboy's headspace...
There are advantages to secondary, like maturation and dry hopping for some but if you're doing a simple beer which is ready to bottle in 2 weeks or less, I agree it's not that useful...
If I dont secondary though, I ALWAYS use a bottling bucket. (That's why I do often secondary... I figure that if I'm gonna transfer anyway, why not secondary. The beer is going to wait "better" if I delay the bottling due to lack of time...)
It's better to start paranoid about sanitation than the contrary, makes you develop good laboratory practices... ;-)
Well, oxidation is an issue. During active fermentation CO2 is being produced and, as your mentioned, being more dense than air it sits nicely over the top of the beer preventing oxygen from getting to it. When you move to secondary, fermentation is presumably done and you are presumably going to keep the beer in there for a while (otherwise, why go to secondary?). If so, the oxygen levels in the headspace will eventually reach an equilibrium with the ambient air. Limiting the headspace - or more appropriately, the surface area of the beer in contact with the headspace - will limit oxidation.
Now, if you keep the beer in secondary for only a short while, oxidation will not be an issue as there will not be enough time for the oxygen levels in the headspace to reach equilibrium. And I see little reason to move a beer to secondary for only a short while.