DIY Tonic Water Recipe

Customize your tonic to match your favorite gin.

Tonic syrup combined with sparkling water in a glass with ice, bottle of tonic syrup in the backround

Serious Eats / Liz Voltz

Why It Works

  • Making your own tonic syrup lets you match the profile of your favorite gin.
  • Try additional aromatics like lavender or orange peel.
  • Combining the syrup with sparkling water as needed allows you to use the tonic syrup over a longer period of time.

Tonic water has come a long way from its humble beginnings as an anti-malaria medicine. Everywhere you turn, there's an upscale bar boasting 'house-made' tonic, and some specialty tonics cost more than the liquor you'd mix them with. The simple G&T isn't so simple anymore.

What's Available to Buy?

From the supermarket to the corner store, you don't have to look far to find the usual suspects—Schweppes, Canada Dry and Seagram's—for under $2 a liter. These taste sweet with a slight citrus tang and a bitter finish. That familiar bitter flavor in tonic comes from quinine. It's naturally found in the bark of the cinchona tree, though quinine we encounter in store-bought tonics was synthesized in a lab. The rest of what we're tasting is high-fructose corn syrup, citric acid, and a preservative called sodium benzoate.

Small producers like Q Tonic, Fentimans, and Fever-Tree use agave nectar or cane sugar instead of corn syrup. Their tonics are made with natural ingredients and taste bolder and more complex, but you'll pay around three times as much as you would for the big brands to indulge your tonic connoisseurship. Fentimans is citrus-heavy, while Fever Tree and Q are more botanical.

Don't feel like a cheapskate if you prefer the familiar brands: Canada Dry consistently comes out toward the top of tonic taste tests. I love Q Tonic, Fentimans, and Fever Tree on their own and with vodka or less-intense gins, but find they sometimes clash with more powerful gins.

Why DIY?

Homemade tonic is really for the hardcore—it calls for obscure ingredients, takes hours to make, and costs a lot more than a bottle of Schweppes. In the end, it doesn't taste the same as the tonic most of us are used to, and it's going to be yellowish-brown instead of clear. If that bothers you, then you're just not going to like the homemade stuff. (But remember, clear isn't always better...how much did you like Clear Pepsi?) If you love the taste of the big brands and want to copy them in your kitchen, you'll be frustrated with making your own.

But 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. Because you control what goes in it, you can match it to your favorite gin's flavor profile and experiment with exotic ingredients. It's not difficult to boil some bark and wait around, but it does take imagination and patience to experiment with more unique flavor combinations. Homemade tonic costs more than Canada Dry, but it's still cheaper than any of the specialty brands.

The main complaint about store-bought tonic is that it's cloyingly sweet and doesn't have enough bite. So for my basic recipe, I matched the typical tonic flavor pretty closely and then upped the bitterness a bit. Try a batch with allspice berries, star anise, and juniper berries if you want something spicier. Lavender, orange, and cardamom would also make for an intriguing tonic.

Three dollars worth of cinchona bark will make about 10 batches of tonic, so it's not too risky to play with different flavor combinations. I tried substituting more citrus for the citric acid powder, but the tonic just didn't have the same zip without it. Citric acid tastes like the powder that coats Sour Patch Kids, so it gives the recipe acidity without adding a specific citrus flavor.

A jar of homemade tonic syrup next to a gin and tonic garnished with a lime wheel.

Serious Eats / Liam Boylan

Use It!

Of course, you can mix your homemade tonic with a plain old gin or vodka. 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. Try an exciting small-batch gin like one of these.

The Oxley Refuge gin & tonic is much more than a G&T, since it uses cream of coconut, lime, Lillet, and cardamom powder. Or serve up a refreshing batch of frozen gin and tonic with cucumber.

November 2011

Recipe Details

DIY Tonic Water Recipe

Prep 10 mins
Cook 70 mins
Active 70 mins
Chilling Time 2 hrs
Total 3 hrs 20 mins
Serves 6 servings

Ingredients

  • 1 lemon

  • 1 lime

  • 2 cups water

  • 2 teaspoons cut cinchona bark (see notes)

  • 1 1/4 teaspoons citric acid powder (see notes)

  • 1 stalk lemongrass, sliced (about 2/3 cup)

  • 1 1/2 cups sugar (see notes)

  • 6 cups carbonated water

Directions

  1. Zest lemon and lime and place in a 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.

    Zested lemon and lime, along with their juices in a medium saucepan, along with water, cinchona bark, citric acid powder, lemongrass, and sugar.

    Serious Eats / Liz Voltz

  2. Reduce heat to medium-low and cook for 45 minutes. Remove from heat and let mixture steep for 20 minutes.

    Tonic water mixture boiling and steeping in the saucepan.

    Serious Eats / Liz Voltz

  3. 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 (see notes).

    Tonic mixture being strained through cheesecloth and a strainer.

    Serious Eats / Liz Voltz

  4. Place tonic syrup in a sealable glass container and refrigerate for at least 2 hours before use.

    Tonic syrup in a sealed bottle.

    Serious Eats / Liz Voltz

  5. To make tonic water, combine syrup with carbonated water, mixing 1 part syrup to 4 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.

    Tonic syrup combined with sparkling water in a glass with ice, bottle of tonic syrup in the backround

    Serious Eats / Liz Voltz

Notes

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.

Nutrition Facts (per serving)
269 Calories
1g Fat
72g Carbs
2g Protein
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Nutrition Facts
Servings: 6
Amount per serving
Calories 269
% Daily Value*
Total Fat 1g 1%
Saturated Fat 0g 0%
Cholesterol 0mg 0%
Sodium 10mg 0%
Total Carbohydrate 72g 26%
Dietary Fiber 5g 16%
Total Sugars 58g
Protein 2g
Vitamin C 87mg 435%
Calcium 83mg 6%
Iron 2mg 9%
Potassium 345mg 7%
*The % Daily Value (DV) tells you how much a nutrient in a food serving contributes to a daily diet. 2,000 calories a day is used for general nutrition advice.
(Nutrition information is calculated using an ingredient database and should be considered an estimate.)