Heat the sugar and water in a 3-quart or larger Dutch oven (or other heavy-bottomed pot) over medium-high heat until boiling.
Add the cranberries, frozen blueberries, cinnamon, and lemon peel (or zest). Allow the mixture to return to a boil, then turn the heat down to medium-low and simmer for 15-30 minutes, until cranberries are burst and softened.
Divide into pint-sized mason jars for storage, leaving a half inch of air space in the top of each jar. Allow to cool on the counter top before refrigerating or freezing.
Serving: 1serving | Calories: 267kcal | Carbohydrates: 69g | Protein: 1g | Fat: 1g | Sodium: 6mg | Fiber: 5g | Sugar: 59g