Step 1

Add the water, sugar, and salt to a saucepan over medium-high heat and boil until the sugar is dissolved. Set aside to cool.

Step 2

To make the watermelon juice, add the cubed watermelon to a blender and blend until it is pureed. You may have to do this in batches depending on the size of your blender.

Step 3

Place a fine-mesh sieve over a large bowl and pour the puree over the sieve. Use a whisk (if desired) to hurry the watermelon through the sieve. Set the strained juice aside.

Step 4

Add 2 cups watermelon juice to the simple syrup and stir. Discard of any extra or reserve for another use. Refrigerate the syrup for up to 4 days, shaking before each use as necessary.