DIY Sour Mix

Notes:
If youd like to use oranges, grapefruits, or agave nectar, keep in mind that they are sweeter than the ingredients in this recipe so youll have to adjust the quantities to taste. Refrigerate the mixture, and it should last a week or two. You can tell its turning if it starts to get cloudy particles. Adding a little vodka will make it keep a month, but it wont taste as fresh after a long storage.

Special equipment: Juicer, fine-mesh strainer

Yield:
Makes about 2.5 cups

Ingredients
1 cup sugar
1 cup water
1 cup freshly squeezed lemon juice
1/2 cup freshly squeezed lime juice

Procedures

Make simple syrup by bringing the sugar and water to a boil, about 7 minutes. Stir to dissolve sugar. Remove from heat and let cool.

While the syrup is cooling, strain freshly squeezed lemon and lime juice into a resealable bottle, discarding the pulp. Pour in the cooled simple syrup. Shake and use immediately or refrigerate.

via DIY Sour Mix | Serious Eats : Recipes.