Wash the fruit carefully. Place it in the saucepan in which it is to be cooked and pour enough cold water over the fruit to cover it. Cover the saucepan and allow the fruit to soak for several hours or overnight. Then cook the fruit at simmering temperature in the water in which it was soaked. When the fruit is tender, remove the saucepan from the fire, add sugar if desired, and stir carefully until the sugar is dissolved. Serve cold.