Recipes Cocktails Tonic Syrup Be the first to rate & review! Use this syrup to make a single Gin & Tonic cocktail or stir up a small batch in a pitcher. The syrup allows you to customize the ratio of tonic to gin to suit your, or your guest's taste. Plus: Ultimate Cocktail Guide By Tim Ludwig Updated on July 14, 2022 Print Rate It Share Share Tweet Pin Email Yield: 12 ounces Ingredients 1 cup water 1 cup sugar 1 lime half 2 fresh lemongrass stalks, coarsely chopped 1/2 teaspoon ground cinchona bark or quinine (see Note) 1 teaspoon citric acid powder or lemon salt (see Note) Directions In a small saucepan, bring the water to a boil. Stir in the sugar, lime, lemongrass, cinchona bark and citric acid powder. Simmer over moderate heat for 15 minutes. Strain through a coffee filter into an airtight container and refrigerate for up to 3 weeks. Notes The bark of cinchona trees produces quinine and it gives homemade tonic water an alluring bitterness. You can buy quinine powder from rain-tree.com. Citric acid or lemon salt is a key ingredient in homemade grenadine, citric acid is a nonalcoholic preservative derived from citrus fruit that also adds tang. Available from bestturkishfood.com. Rate it Print