Preheat the oven to 400°F. Rinse the quail and pat dry with a paper towel. Season each generously with salt and pepper. Brush the outside with olive oil or bacon grease. Stuff the cavity of each quail with the grapes and a sprig of rosemary. Place in a heavy roasting pan. Roast for 25 to 30 minutes, basting occasionally with the white wine, until the legs wiggle easily in the sockets. Leave to rest for about 10 minutes before serving. Serve with rice pilaf or garlic mashed potatoes.