In a small saucepan, set over medium heat, bring the sugar, water, lime juice, and lime zest to a boil. Remove from the heat and stir until the sugar is dissolved. Cool completely before making limeade. (If desired, strain the Lime Simple Syrup through a mesh strainer set over a bowl to remove the lime zest. Some people love the zest in their limeade and some don’t.)
1 cup granulated sugar, 1 cup water, 6 tablespoons fresh lime juice, 4 teaspoons lime zest