I May have stumbled onto a good idea.

[johnd4]

I use a Coleman 5 US Gallon water jug as a primary. Since I make 2 /12 gallons at a time, there is lot of headspace. I take a dry cleaner plastic bag, split it to form a sheet and push down in the container to about 2 inches above the level of the liquid-I do this after the very active stage of the yeast is over-about the 3rd-4th day. The flexibility of the plastic allows for temperature expansion and contraction so outside air never actually gets to the beer. Seems to work pretty well. Anybody else ever try this?

 

[android]

are you trying to prevent oxidation? i would assume after fermentation, the headspace has been purged of most oxygen and if you're not leaving it in there for a super long time, oxidation shouldn't be much of an issue... don't you rifle through that 2.5 gallons in no time??

 

[MistyMountainHops]

... don't you rifle through that 2.5 gallons in no time??

Man - 2.5 gallons at a time sounds depressing. I would feel so restricted.