Ingredients

Orange Reduction:

2 1/ 4 cups fresh orange juice

Strips of zest from 2 navel oranges

Three 3-inch-long cinnamon sticks, broken into pieces

Punch:

3 cups fresh orange juice

2 cups fresh red grapefruit juice

1 tablespoon grenadine syrup

2 1/2 cups cold grapefruit soda (20 ounces)

Orange slices and ground cinnamon, for garnish

Preparation

Orange Reduction: In a saucepan, boil the orange juice, zest and cinnamon sticks over moderately high heat until reduced to 1 cup, 8 minutes. Strain and let cool.

Punch: In a large glass pitcher, combine the orange reduction with the orange and grapefruit juices and the grenadine. Stir well and refrigerate until chilled, about 1 hour. Just before serving, pour in the grapefruit soda. Dust the orange slices with cinnamon and serve in the punch.