Step 1

Preparation Combine 2 cups blackberries, frozen + 1 1/2 cups raspberries, frozen + 6 ounces light rum + 4 ounces simple syrup + 1 1/2 ounces fresh lime juice + 2 cups ice. Optional garnish: Blackberries Cook's Notes:Head to the farmers' market for peak-season fruit. Freeze the fruit in a single layer on a parchment-lined baking sheet until solid. Purée ingredients in a blender until smooth and very thick. Divide among glasses and serve.Cold Facts:The drier the ice, the better. Melting ice makes for a watery cocktail.No need to upgrade your blender. The old one will do the trick just fine.Texture Matters:Frozen drinks should look too thick when poured into the glass. They will loosen immediately.

Step 2

Preparation Combine 2 cups blackberries, frozen + 1 1/2 cups raspberries, frozen + 6 ounces light rum + 4 ounces simple syrup + 1 1/2 ounces fresh lime juice + 2 cups ice. Optional garnish: Blackberries Cook's Notes:Head to the farmers' market for peak-season fruit. Freeze the fruit in a single layer on a parchment-lined baking sheet until solid. Purée ingredients in a blender until smooth and very thick. Divide among glasses and serve.Cold Facts:The drier the ice, the better. Melting ice makes for a watery cocktail.No need to upgrade your blender. The old one will do the trick just fine.Texture Matters:Frozen drinks should look too thick when poured into the glass. They will loosen immediately.