Rinse the Cranberries under cold water and pick out any stems or soft berries.
Place the rinsed Cranberries in a medium saucepan with the Water. Use roughly 2 parts water to 1 part cranberries as a starting ratio for a pitcher-sized batch.
Bring to a gentle boil over medium heat, then reduce the heat and simmer for 10–15 minutes, until the berries have burst and released their juice.
Use a potato masher or the back of a spoon to gently mash the berries in the pot, simmering another 2–3 minutes to extract as much flavor as possible.
Strain the mixture through a fine-mesh sieve or cheesecloth into a bowl or pitcher, pressing on the solids to extract all the juice; discard the pulp or reserve it for another use.
While the juice is still hot, stir in Granulated Sugar to taste so it dissolves easily—start with about 1/2 cup sugar per 2 cups of strained juice and adjust depending on how tart you like it.
Cool the morse to room temperature, then refrigerate until cold. Taste and, if desired, dilute with a little extra cold Water or sparkling water before serving to reach your preferred intensity.
Serve over ice and store any leftover morse in the refrigerator for up to 4–5 days; shake or stir before pouring, as natural settling may occur.
