Combine the orange zest, juice, sugar and water in a saucepan over medium heat and simmer until the sugar dissolves then add the cranberries. Simmer until the cranberries begin to burst and the mixture has thickened, around 10 -15 minutes.
Let the sauce cool completely to room temperature, or chill in the refrigerator before serving.
Notes
Spiced cranberry sauce: You can add a cinnamon stick to the mixture when you add the cranberries if you prefer some spice. When finished remove the cinnamon stick before serving.Smooth cranberry sauce: If you prefer cranberry sauce without skin, press the mixture through a fine mesh strainer into a bowl using a wooden spoon and discard the skins.