- In a small saucepan, bring the water, sugar and mint to a boil. Remove from the heat. Let cool completely.
- Filter the mint syrup. Keep in an airtight container in the refrigerator.
- In a glass, combine the bourbon and ½ oz (15 ml) of the mint syrup (see note). Generously fill the glass with crushed ice. Garnish with the mint sprig and dust with icing sugar, if desired. Serve with a straw.
The syrup will keep for about 3 weeks in the refrigerator.