For spice bag, cut a double thickness of 100 percent cotton cheesecloth into a 5- or 6-inch square. Pinch cardamom pods to break open. Place cardamom, cloves, and cinnamon in center of cheesecloth square. Bring up corners of cheesecloth and tie with a clean string.
In a 3-1/2-, 4-, or 5-quart crockery cooker combine wine, water, and corn syrup. Add spice bag.
Cover; cook on low-heat setting for 4 to 5 hours or on high-heat setting for 2 to 2-1/2 hours. (Do not let boil.) Add orange halves the last 1/2 hour of cooking. Remove spice bag and orange halves and discard.
To serve, ladle beverage into cups. If desired, float a fresh orange slice atop each serving and add a cinnamon stick. Makes 12 (6-ounce) servings.