1 (12 fluid ounce) can frozen concentrated grapefruit juice
1 (12 fluid ounce) can frozen cranberry juice concentrate
1/4 cup coconut milk
9 cups cold water
In a 6 quart container combine concentrated grapefruit juice, concentrated cranberry juice and water. Put about 1 cup of juice and coconut milk in food processor or blender. Blend until smooth and pour back into main juice mixture. Stir to incorporate.
Chill at least 2 hours. Serve in punch bowl or pitcher.