6.5 gallon secondary for 5 gal of brew?

[Bills Brew]

I just transfered my 5 gallons of brew from the plastic primary to a 6.5 gallon secondary glass carboy, because that is what I had. Obviously, there is a quite a bit of empty head space above my brew. It seems to me that because fermentation has slowed, and almost stopped, the chance that enough CO2 will be generated is doubtful. This means the headspace will be mostly oxygen and very little CO2 and could be bad for the brew.

So my question is: is this a bad practice and am I inviting nasty things to grow in there? Or should I not worrry about it and have a brew?

I suppose the right thing to do is to use the 6.5 carboy as my primary and buy a 5 gallon glass carboy for my secondary, but I was just curious what the experienced brewers thought.

Thanks for your comments.

 

[Walker]

I just transfered my 5 gallons of brew from the plastic primary to a 6.5 gallon secondary glass carboy, because that is what I had. Obviously, there is a quite a bit of empty head space above my brew. It seems to me that because fermentation has slowed, and almost stopped, the chance that enough CO2 will be generated is doubtful. This means the headspace will be mostly oxygen and very little CO2 and could be bad for the brew.

So my question is: is this a bad practice and am I inviting nasty things to grow in there? Or should I not worrry about it and have a brew?

Have a brew. True, fermentation has basically stopped at this point, but the act of racking the beer will knock loose a bunch of CO2 that is dissolved in the beer, and that will produce enough of a protection blanket to keep the air away from the beer. Just don't knock it around a lot after racking.

I suppose the right thing to do is to use the 6.5 carboy as my primary and buy a 5 gallon glass carboy for my secondary, but I was just curious what the experienced brewers thought.

Yep. Buy a 5 gallon carboy for use as a secondary and use that 6.5 for a primary.

-walker

 

[Bills Brew]

Thanks,

Actually, that will make life easier. It is a lot easier to remove the stopper from a carboy than it is to pry the lid off the plastic bucket.