Confectioners' sugar Thread a needle with -20ºC oot length of white, heavy-duty carpet thread. Tie a knot 20 cm from the end. Carefully string 20 walnuts. Tie a knot after the last walnut. Tie thread ends together forming a necklace. Repeat for remaining 20 walnuts. Divide the grape juice concentrate. From one half, pour one third cup into a jar. Pour the remaining amount of that half into a small saucepan. Heat to boiling. Spinkle 5 teaspoons of cornstarch into the jar of juice. Shake vigorously. Gradually stir into boiling juice. Cook until thick enough to heavily coat spoon. Remove from heat. Dip one "necklace" into grape juice until every nut is coated. Hang loop in an airy spot. Dip and hang second necklace. Allow to hang 30 minutes. Repeat the whole procedure. Dry necklaces several days until coating is no longer sticky. When dry, repeat dipping. Use the remaining half of grape juice and cornstarch. Dip necklaces twice. Let hang to dry a week. When dry, snip knotted thread. Carefully pull out. Dust rolls with confectioners' sugar. Slice into 1 cm rounds. Makes two 18 cm rolls.