1/2 cup thinly sliced peeled ginger
4 plump stalks of fresh lemongrass, cut into 2-inch lengths and smashed, plus stalks for garnish
6 cups water
1 cup sugar
3 tablespoons freshly squeezed lemon juice
Lemon wheels and ice cubes, for serving
- In a medium saucepan, combine the sliced ginger with the smashed lemongrass and 4 cups of the water and bring to a boil over high heat. Stir in the sugar. Cover and let the ginger-lemongrass syrup steep off the heat until cool, about 2 hours.
- Strain the syrup through a fine-mesh sieve. Discard the ginger and lemongrass. Stir in the lemon juice and the remaining 2 cups of water. Refrigerate until chilled.
- Make the soda according to the manufacturers' directions. Serve in tall glasses over ice, garnished with lemon wheels and lemongrass stalks.
The recipe can be prepared through step 2; refrigerate up to 5 days.