Rinse the cranberries thoroughly in cold water and discard any soft or damaged berries.

In a medium saucepan, combine the water and granulated sugar.

Bring the mixture to a boil over medium-high heat, stirring occasionally until the sugar is completely dissolved.

Add the cranberries to the saucepan and return the mixture to a boil.

Reduce the heat to medium-low and simmer for approximately 10 minutes, or until most of the cranberries have burst and the sauce has begun to thicken.

Stir in the orange zest and a pinch of salt.

Remove the saucepan from the heat and allow the sauce to cool completely at room temperature.

Transfer to a covered container and refrigerate until chilled; the sauce will continue to set and thicken as it cools.