Ingredients:

• 3 cups water
• 3 stalks lemon grass, coarsely chopped
• 1 cup sugar
• 1/2 tablespoon quinine powder
• 1 teaspoon citric acid
• 1 teaspoon lime juice
• 20 ounces sparkling water, chilled

Directions:

In a medium saucepan over medium-high heat, bring the 3 cups of water to a boil. Add the lemon grass, sugar, quinine powder, citric acid and lime juice and return to a boil. Reduce the heat to medium or medium-low and simmer for 45 minutes to 1 hour, until the mixture is syrupy and has reduced by half. Strain the syrup twice — first through a fine-mesh strainer and then through a coffee filter (it will strain very slowly through the filter) — and refrigerate, covered, for at least two hours. Measure out 5 ounces of the cold syrup and add to the sparkling water. (Reserve the remainder of the syrup for a second batch, if desired.) Transfer to a soda siphon and dispense with a CO2 charger. If you do not have a siphon and charger, do not combine the syrup and water until immediately before use.