Bring water, sugar, salt, and zest to boil over high heat in a small, non-reactive saucepan.

Add cranberries. Return to a boil, then reduce heat to medium.

Simmer ~ 5 minutes until saucy and thickened, and about 2/3 of the cranberries have popped.

Off heat, stir in liquor. Cool to room temperature before serving. Can be refrigerated for up to 5 days.