This recipe appears in:DIY vs. Buy: Should I Make My Own Tonic Water?
If you're unhappy with the flavor of commercial tonics and like to geek out in the kitchen, DIY tonic is a lot of fun. This basic recipe goes well with gin and is a great starting point for playing with your own unique herb and spice combinations.
- The tonic is going to be yellowish-brown in color. This is a normal and natural result from using cinchona bark instead of synthetic or pharmaceutical quinine. Lhasa Karnak sells cinchona bark online and at their Berkeley locations. Some Latin or Asian markets carry it as well. I used cut bark rather than powder, because it is easier to filter and provides a bold flavor.
- Citric acid powder, also known as sour salt, is easy to find at most markets, but you can order it online from Amazon, too.
- You can substitute agave nectar for the sugar, but be aware that you will need less—about 2/3 cup of agave for every 1 cup of sugar.
- If you don't have cheesecloth, you can strain the mixture through a fine-mesh sieve and then strain again through a coffee filter.
- For the carbonated water, you can buy seltzer or unsalted sparkling water, or you can carbonate your own water using an old fashioned soda siphon or Sodastream machine.
- 1 lemon
- 1 lime
- 2 cups water
- 2 teaspoons cut cinchona bark
- 1 1/4 teaspoons citric acid powder
- 1 stalk lemongrass, sliced (about 2/3 cup)
- 1 1/2 cups sugar
- 6 cups carbonated water
Zest lemon and lime and place in medium saucepan. Juice lemon and lime and add juice to saucepan, along with water, cinchona bark, citric acid powder, lemongrass, and sugar. Bring to a boil on high heat.
Reduce heat to medium-low and cook for 45 minutes. Remove from heat and let mixture steep for 20 minutes.
Strain mixture through two layers of cheesecloth placed in a fine-mesh sieve. Strain again if there are still particles to be removed. This liquid is the tonic syrup.
Place the tonic syrup in a sealable glass container and refrigerate for at least two hours before use.
To make tonic water, combine the syrup with carbonated water, mixing one part syrup to four parts water. Do not combine them in a large batch unless you intend to use all the tonic water at once. Instead, combine syrup and fresh carbonated water for each individual use.