Rinse cranberries. Pick out and discard any damaged or bruised cranberries.

Put the water, juice and sugar in a medium saucepan on high heat and bring to a boil. Stir to dissolve the sugar.

Add the cranberries to the pot and return to a boil. Lower the heat and simmer for 10 minutes or until most of the cranberries have burst.

Once the cranberries have burst you can add the orange zest and grand marnier. 

Remove the pot from heat. Let cool completely at room temperature, then transfer to a bowl to chill in the refrigerator. Note that the cranberry sauce will continue to thicken as it cools.