I have split up a 4 gal mead into blackberry melomel, blueberry melomel and peach melomel.. I have put 1 oz of American oak in both the blackberry and blueberry. Not having ever used oak before I think I need a little guidance. Fermentation seems to have ceased in the mel but I haven't just stood there and stared at it. I thought some mead was done once and tried bottling it. Wrong, don't want to make that mistake again. How long should I leave these on the oak? My intent is to leave these three under airlock for at least 6 months. The rest of the mead is still under lock until I make up my mind what else to do.