Oxidize my beer or water it down?

[Dmp]

Okay so I'm doing a 3 gallon batch. I started with 3.5 gl and between the boil and steeping a gallon of water vanished. Now I know that left me with only 2.5 gallons of wort....with the extra air in the primary carboy (a five gallon carboy) should fine because it the yeast needs the air at first, but when transferred into the 2ndary there will either be half a gallon of oxidizing bad air in the carboy....or else I will have to add half a gallon of boiled sanitized water to the batch. What to do...Hmm.....

[ajdelange]

It isn't the volume of air in the carboy that is important but rather the area of the interface between the air and the beer. An extra half gallon or even gallon of air in a carboy won't make a difference as long as the beer is blanketed with CO2. If you transfer to secondary while the beer is still gassy then the mechanical disturbance of transfer should release this gas as the beer enters the new carboy and that gas, being heavier than air, should protect the surface of the beer. If you want to be extra sure shoot some CO2 into the carboy through a tube connected to your gas bottle. If you don't have a gas bottle mix vinegar and baking soda in a pitcher and pour the gas which evolves (not the liquid) into the carboy. You won't be able to see what's happening but the CO2 is enough denser than air that it does pour almost like water.

[Blowmax10]

or..

Don't even use a secondary - that's what I would do

[Dmp]

I was leaning more towards adding the water since the wort seemed super fucking heavy too.

[brewinhard]

Both are great ideas. If the beer is average alcohol strength why even go to secondary. I rarely secondary unless I am lagering, adding bugs, or oak/fruit aging. If you feel the need to transfer to secondary then definitely transfer before the beer is done fermenting all the way so the yeast can consume any oxygen introduced and the head space in carboy can be purged with CO2 by the outgassing of the fermenting beer.

[Dmp]

Awwww thanks brewinhard. Yes I will transfer, a bit before the fermentation hits the 2nd phase (while the airlock is bubbling before every two minutes). And see the batch looks super freakin heavy. ALthough I didn't do a gravity reading I calculated it out and its somewhere 1.065 (at three gallons) So I can only imagine how high the gravity is/was with 2.5 gallons.

[brewinhard]

Why not then slowly add your water to make up your batch size into the carboy first (boiled and cooled of course to reduce shock on carboy and remove as much possible dissolved oxygen from the water) and carefully rack the still fermenting beer on top?

[Dmp]

oh ya. umm duh! that's what I will do since tonight is day 2 or 3 only...
I get it because the layer of co2 will protect it plus its still fermenting....DUH!