Tonic Water
Makes about 1 quart (1L)
Adapted from Bitter: A Taste of the World’s Most Dangerous Flavor by Jennifer McLagan I changed up the spice mixture from what Jennifer used and tinkered (ie: customized) a few other things. Some people add a teaspoon of dried lavender to their tonic water infusing along with the allspice, and I also included some cardamom, since I like that elusive flavor in my cocktails. I used chopped chinchona bark, not powdered chinchona, which comes broken into little pieces. I’ve listed sources for that, as well as the citric acid, after the recipe. If you can’t gather all four citrus fruits, feel free to substitute one for another, ie: 2 oranges instead of 1 grapefruit and 1 orange. Since you’re using the peel, it’s best to use organic or unsprayed citrus fruits. To make the simple syrup, bring 1 1/4 cup (250g) of sugar to a boil with 1 cup (250ml) of water, stirring frequently, for one minute, until the sugar is completely dissolved. To use this tonic water, mix it 1:1 (in equal parts) with sparkling water or club soda.
1 quart (1L) water
1 grapefruit
1 orange
1 lemon
1 lime
2 1/2 ounces (75g) chopped lemongrass (use the bottom 2/3rds of the stalks, trimming off the root end first)
3 tablespoons (33g) citric acid
1/4 cup (22g) chopped chinchona bark
10 allspice berries
5 cardamom pods, slightly crushed
2 small star anise
1 teaspoon coarse sea or kosher salt
1/4 teaspoon black peppercorns
1 1/2 cups (375ml) simple syrup (see headnote)
1. Pour the water into a medium-sized nonreactive saucepan. Add the zest from the grapefruit, orange, lemon, and lime. (You can remove it with a sharp vegetable peeler, in strips, or with a citrus zester.) Halve, then juice the citrus fruits and add the juice to the saucepan.
2. Add the lemongrass, citric acid, chinchona bark, allspice, cardamom, star anise, salt, and black peppercorns. Bring the mixture to a boil and reduce to a simmer. Cover with a lid, leaving it slightly askew, and let it simmer gently for 15 minutes. Remove from heat, uncover, and cool to room temperature.
3. Pour into a container, such as a large screw-top jar, and chill for 2 days in the refrigerator, shaking it gently a couple of times a day.
4. Strain liquid through a fine mesh strainer, preferably into a large measuring cup (which will make the next step easier). Discard the spices, lemongrass, bark, and citrus peels. Strain the mixture again, this time through a strainer lined with several layers of cheesecloth, muslin, or a coffee filter. (If using a coffee filter, it’ll remove most traces of the spice powder but it’ll take a bit of time, so be patient.)
5. Add the sugar syrup, then pour into clean bottles or screw-top jars and refrigerate until ready to use.
To use the tonic water: Pour off the tonic water, avoiding disturbing any bark and spice sediment that might settle into the bottom of the bottle or jar, then add an equal amount of sparkling water to obtain the quantity that you need. So to make 1 cup (250ml) of tonic water, you’ll use 1/2 cup (125ml) of the tonic water mixture, and 1/2 cup (125ml) sparkling water.

Storage: The tonic water can be kept for several months in the refrigerator. Don’t tighten the lid as the tonic water can ferment a bit and you want any air to be able to escape.