Step 1

In a small saucepan over medium high heat, whisk together the sugar and water until the sugar is dissolved and the mixture is barely thickened, about 5 minutes. Remove from the heat, let cool, and transfer to an airtight container. This recipe makes about ¾ cup, or 6 ounces, and you won’t use it all in this drink: Store leftovers in an airtight container in the refrigerator for up to 1 month.

Step 2

Rinse the strawberries and dry them on a kitchen towel. Place the berries in a single layer on a parchment-lined sheet pan and freeze completely, about 2 hours. Transfer the frozen berries to an airtight freezer-safe container and store in the freezer until ready to use.

Step 3

Combine the frozen strawberries, rum, simple syrup, lime juice, lime zest, and salt in a blender. Purée until smooth.

Step 4

Pour into a glass and serve immediately.