Turn mixture in ice cream maker per maker's instructions or until mixture reaches the consistency of a firm slush. Return mixture to lidded container and harden in freezer 1 hour before serving.
If sorbet is to be held frozen for longer than 2 hours, move from freezer to refrigerator for about half an hour before serving. If you'd like a more assertive sorbet, double the amount of citrus zest.
Prep Time: 15 minutes Cook Time: 3 hours 15 minutes