In a medium saucepan, combine the port, maple syrup, star anise, salt and 1/2 cup water.

Bring to a boil over medium-high heat, stirring to blend. As soon as it starts to boil, remove it from the heat, cover and let stand for 20 minutes to infuse the star anise into the liquid.

Pick through the cramberries fro stems, rinse them well in a colander and drain.

Return the liquid to boil over medium high heat and add the cranberries. When the mixture again returns to a boil, lower the heat to a simmer and cook, occasionally stirring gently, until most of the berries have popped open and the sauce thickens slightly. 8-10 minutes.

Discard star of anise. Stir in zest and let sauce cool to room temperature.