Simple syrup can be stored in an airtight container in the refrigerator for as long as two months. The recipe can easily be doubled or tripled so that you always have some on hand.
Prepare an ice-water bath. In a large saucepan, combine sugar and water; bring to a boil over medium-high heat. Cook until sugar has completely dissolved, about 10 minutes. Transfer the syrup to a bowl, and set the bowl over the ice-water bath. Let stand, stirring occasionally, until thoroughly chilled before using or storing.