Tonic Syrup

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.

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.