1. Bring the cranberries, sugar, orange juice, and rosemary to a boil in a large saucepan over medium-high heat.
2. Reduce heat and simmer for 1 minute (some berries will pop and some will remain whole)
3. Remove saucepan from heat and stir in zest.
4. Cover and let stand for 10 minutes.
5. Let sauce cool to room tempaerature, then cover and refrigerate.
6. Return to room temperature before serving.
Can be made up to a week ahead and refrigerated in a covered container.