Cranberry juice (optional) Balsamic vinegar, to taste CUT EACH QUINCE INTO QUARTERS, then cut quarters into pieces about 1 cm thick. Grasp each piece firmly and cut away peel and core with sharp knife. When all slices have been cored and peeled, cut each piece into small chunks. Don't worry about the fruit discoloring. In saucepan, combine water, sugar, spices and orange peel. Bring mixture to boil, stirring to dissolve sugar. Add quince. Reduce heat, cover pan and cook very slowly until fruit has turned a deep pink color, about 2 hours. You don't need to worry about overcooking as the fruit will hold its texture well. If cooked slowly, there should still be quite a bit of liquid in pan when fruit is done. Sort through cranberries, remove those that are not in good shape and rinse the rest. Add cranberries to cooked quince. If mixture seems too dry, add a little more water or cranberry juice. Increase heat a little and cook cranberries until they begin to pop open, 12-to-15 minutes. Use rubber scraper to gently mix them with quince. When done, refrigerate compote to cool, then stir in enough vinegar to balance the sweetness.