I've just finished fermenting my Frontenac Gris from this years harvest. I ended up with a little over 2.5 gals after racking. My question is how to handle the 1/2 gal. in terms of air exposure? I don't have quick access to CO2 to fill the air space in the third one gallon jug. Should I rack back into one of my 3 gal. carboys and then add some wine (from last years harvest) to top off the carboy? Or is it too soon to add finished wine (basically I'm in secondary fermentation) and should I add something else to get me to three gallons?