Start by rinsing the cranberries under cold water and removing any stems or soft berries. I always take a minute to sort them properly because it ensures the final sauce tastes clean and fresh.
In a medium saucepan, combine the water and sugar over medium heat. Stir until the sugar completely dissolves and the mixture comes to a gentle boil, forming a light syrup base.
Add the cranberries to the boiling syrup and reduce the heat to a simmer. Cook for about 10 minutes, stirring occasionally, until most of the berries burst open and release their juices.
If you’re using orange zest, spices, or dried fruit, stir them in once the berries have popped. This is when the sauce develops deeper flavor and a wonderful aroma.
Remove the saucepan from heat and let the sauce cool at room temperature. As it cools and chills in the refrigerator, it naturally thickens into a glossy, spoonable consistency.