Homemade Indian Tonic Water

This is a simple tonic water recipe made by adapting and combining two of my favorites out there, one by David Debovitz and the other from Pinch and Swirl. You can feel free to tweak the spices to your taste (Lebovitz uses black pepper but no lavender for example); you have lots of choices. You can also modify the citrus range and quantity--I'm keeping mine Indian with the use of pomelo, for instance--and leave out the juice, just using zests. But don't leave out the cinchona, citrus, lemongrass, and citric acid, whatever you do.

Print Recipe

Ingredients

3 cups water
Zest or thinly cut strips of 2 oranges, 2 large lemons, 2 large limes, and ¼ a large pomelo (or ½ a grapefruit)—and about 1 cup combined juice from each
2 lemongrass stalks, white portions only, chopped
3 tablespoons citric acid
1/4 cup chopped cinchona bark
10 allspice berries
5 cardamom pods, slightly crushed with the skins on
2 star anise
1 tablespoon lavender
1 teaspoon sea salt

For the simple syrup

1 ½ cups water
2 cups sugar

Instructions

Prep the ingredients

Mostly this involves cleaning and getting the citrus zests ready. I find a sharp peeler works better for this than any citrus zester out there. Careful you don’t get too much of any of the white portions of the citrus peel, as that would add rather more bitter tastes to the tonic than you want. Cut in strips as in the images above and set aside.
Also juice the citrus fruits and set aside about a ½ cup to 1 cup of juice, preferably with no pulp or as little pulp as possible. You can omit this, and just go with the zests, too.

Prepare the tonic

Bring the 3 cups of water to a simmer, then cool until it's on the hotter side of warm.
Add all the solid ingredients to a 1 litre jar, preferably one with a mouth wide enough to allow for some mixing and a good lid. Then pour the slightly warm-to-hot water over top. Close the bottle tightly and agitate to mix.
Cool completely. Refrigerate this mixture for 3-4 days, making sure to mix the ingredients well each day, either with a wooden spoon or with a vigorous shake.

Make it a syrup

First prepare your simple syrup. Mix 2 cups of sugar with 1 ½ cups of water, dissolving the sugar completely and bringing this to a gentle boil for a few minutes. Switch off the heat, and allow this to cool completely.
While it’s cooling, retrieve your tonic water infusing jar from the fridge and strain the liquid. You may have to do this a few times to get the finer powders out (especially if you used cinchona powder instead of bark pieces). You can use a cheesecloth or a coffee filter. The infused liquid should taste rich, citrusy, complex, with deep bitter tones.
Add the sugar syrup, then pour into clean bottles and refrigerate until ready to use. This keeps well in the fridge for several months.

Use the tonic water

Use the tonic water with either water or soda in a 1:2 dilution ratio, or to taste. If you’re combining water and soda, then it’s 1 part tonic: 1 part water: 1 part soda or sparkling water.
Gin and tonic would be just slightly differently proportioned: ½ oz tonic water (that’s roughly 1 tablespoon), 2 oz gin (or more, that’s your call!) and 2 oz soda or sparkling water (or more, or less!)
Either way keep in mind that we don’t really know how much quinine is extracted in this process, and it’s better to have less than more.
You don’t need an extra lime squeeze on this one because there’s already plenty of citrus in the tonic water, unlike what you get with commercial brands.
Keep in mind also that this home made tonic water syrup will be a lot less sweet than the commercial varieties—you may well end up wanting to add more tonic water to compensate, or (better) some other sweetener like agave or honey can work well, too. Don’t add too much though; the bitters are what make this drink both unique, effective, and distinctive.