How to Make Your Own Tonic Water - Jeffrey Morgenthaler

Combine ingredients in a medium saucepan and bring to a boil over high heat.Once mixture starts to boil, reduce heat to low, cover and simmer for 20 minutes.Remove from heat and strain out solids using a strainer or chinois.You'll need to fine-strain the mixture, as it still contains quite a bit of the cinchona bark. You can use a coffee filter and wait for an hour or more, or do as I do and run the whole mixture through a French coffee press.Once you're satisfied with the clarity of your mix, heat it back up on the stovetop or microwave, and then add ¾ cup of agave syrup to each cup of your hot mix. Stir until combined, and store in the attractive bottle of your choice.You now have a syrup that you can carbonate with seltzer water; I use my iSi soda siphon for some nicely-textured bubbles.To assemble a gin and tonic, use ¾ ounce of syrup, 1½ ounces of gin and 2 ounces of soda water over ice.