Eight days ago the SG on my 5 gallon batch of muscadine wine was at 0.994 so I racked to carboy, added campden tabs and sorbate, topped off with a finished wine, added air lock and put away to start clearing. Tonight I notice fine bubbles making their way up through the wine and forming a ring at the neck of the carboy. I stirred the wine vigorously after racking. Could this still be the carbon dioxide from the initial fermentation?