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I believe we’ve done the work to call this the ultimate Gin and Tonic recipe.

After several attempts to make an exceptional homemade tonic syrup – including this famous recipe from Jeffrey Morgenthaler, and this one from Lottie + Doof, via Tony Cecchini and the NYTimes – Keith and I were unsatisfied. In all cases, we liked the tonic, but we didn’t love it. Our biggest complaint – we couldn’t taste the gin.

Homemade-Tonic-Water served with gin and tonic cockatails

Gin is divisive, isn’t it. Do you know anyone who’s on the fence about it? People seem to either shrivel in horror or swoon with delight at the mention of it. Those who swoon like the flavor of gin, and why? Because it’s loaded with botanicals – primarily juniper, but look at this list of other essences you might experience.

After each attempt at a homemade version, we would end up back with our favorite store-bought tonic, Fever Tree Naturally Light. It’s light, not in a phony sugar way, but in a less-sugar way – a plus as most store-bought tonics are ridiculously sweet. It’s only slightly bitter, and has a fresh citrus flavor. But it’s also understated, too much so once you’ve tried a homemade version. So it was our muse, but we hoped for something even better.

How to Make Tonic Water

We started the experiment to create our own recipe with 3 criteria:

  1. The syrup had to be delicious, but subtle enough to accentuate, not overpower the gin flavor.
  2. It had to be cold extracted because cooked citrus zest tastes, well, cooked.
  3. It needed to be just barely sweet and pleasantly bitter.
Homemade Tonic Ingredients

We decided to try 2 versions – both had the basics: cinchona bark (the natural source of quinine), and citric acid (necessary for extraction and helpful for preserving).

Zested Citrus for Homemade Tonic Water
Citrus zest for homemade tonic

The first version had just citrus zest and lemongrass. The second had zest, lemongrass, and other botanicals: cardamom, lavender, allspice.

Homemade Tonic Ingredients Ready For Water
Tonic Ingredients with Water

We filled our jars with filtered water, shook them daily, and allowed them to steep for 72 hours. I firmly believed that the version without the additional botanicals would prevail.

I was wrong, sort of.

Think of vanilla extract. Take in that incredible aroma and you’re tempted to take a swig. Or you were tempted before you tried it straight the first time. On it’s own, the extract is bitter and pungent. But in the proper proportion, added to a sugary or savory recipe, is matchless. Tonic syrup is like that.

You can’t try a couple of syrups straight and determine which is superior. You have to make a proper drink and try them side by side. Work, work, work!

Ultimate-Gin-and-Tonic-pictured with-Homemade-Tonic-Water

We did our careful taste-testing and were surprised by the result. Both were excellent. Both were missing something. So we took a chance and combined the two. And, Success! Really, the BEST gin and tonic either of us had ever tasted.

What began as rivalry ended in alliance.

Bottoms up!

More Classic Cocktails

And if you’re interested in trying other delicious classic cocktails, I recommend the very herbaceous Last Word Cocktail, my Blackberry Margarita recipe, this Boulevardier Cocktail recipe, this Peach Bellini recipe, and this French 75 Cocktail!

Recipe Update: Several people asked about ingredient weights and I finally got around to weighing as I went – because really, there can be a huge difference in size from one citrus fruit to another or between stalks of lemongrass. 

I’ve also increased the amount of rich simple syrup based on recommendations (looking at you, Ken Smith 🙂 ), from several people who commented on the original post – it still only comes out to be 1 1/2 teaspoons of sugar per drink and really does make for a smoother, more balanced flavor. However, if you prefer your tonic more tart / bitter, stick with the original amount of syrup: 2 cups sugar and 1 cup water.

Homemade Tonic Water Recipe Video

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Homemade Tonic Water for the Ultimate Gin and Tonic

4.73 from 18 votes
Prep: 15 minutes
Cook: 15 minutes
Total: 30 minutes
Course: Drinks
Calories: 26
Servings: 96 servings
Note: Penn Herb Co. is a great, and economical, source of Cinchona Bark. For the other ingredients, look in the bulk spice area of your local grocery or health food store.
Note: Dry ingredients are listed by weight, liquid ingredients are listed by volume.

Ingredients  

  • 3 cups water (675 ml)
  • ¼ cup chopped cinchona bark (1 ounce / 28 grams)
  • ¼ cup citric acid (2.2 ounces / 62 grams)
  • 3 limes peeled zests only (0.4 ounce / 11 grams)
  • 3 lemons peeled zests only (0.5 ounce / 14 grams)
  • 2 oranges peeled zests only (0.5 ounce / 14 grams)
  • 3 stalks lemongrass tops and bottoms trimmed and outer leaves removed then sliced into 1/8″ to 1/4″ rounds (2.5 ounces / 71 grams)
  • 4 whole allspice berries
  • 3 whole green cardamom pods
  • 1 tablespoon lavender
  • ¼ teaspoon kosher salt

Rich Simple Syrup

  • 3 cups natural cane sugar (21 ounces / 600 grams)
  • 1 1/2 cups water (355 ml)

You’ll also need:

  • Lime wedges
  • Sparkling water

Instructions 

  • Combine all ingredients except rich simple syrup in a sterilized, one-quart lidded glass jar. Shake to combine. Refrigerate 72 hours, shaking occasionally, at least once per day.
  • Make rich simple syrup: dissolve 3 cups sugar in 1 1/2 cups water over medium heat until sugar is completely dissolved. Allow to cool. Transfer to a container and refrigerate.
  • After 72 hours, strain tonic mixture into a large glass pitcher. Strain tonic a second time, using a coffee filter or very fine cheesecloth.
  • Whisk simple syrup into tonic until thoroughly combined.
  • Pour tonic syrup through a funnel into storage bottles and store in the refrigerator.

For the Ultimate Gin & Tonic

  • Fill a highball glass with ice. Add 1 tablespoon tonic syrup, 2 ounces gin, and 2 ounces sparkling water. Stir to combine. Serve with a lime wedge (about 1/6 of a fresh lime). To drink: squeeze the lime wedge into the drink, then drop it in. Enjoy!

Notes

Carefully wash citrus fruits and lemongrass before zesting / chopping.

Nutrition

Calories: 26kcal | Carbohydrates: 7g | Protein: 1g | Fat: 1g | Saturated Fat: 1g | Sodium: 7mg | Potassium: 17mg | Fiber: 1g | Sugar: 7g | Vitamin A: 10IU | Vitamin C: 3.9mg | Calcium: 4mg | Iron: 0.1mg

Nutrition information is automatically calculated, so should only be used as an approximation.

Leave a comment & rate the recipe below!

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130 Comments

  1. Alec says:

    I made my first batch of your Homemade Tonic Water and it is spectacular! My wife and I have been enjoying Gin & Tonics more than usual this summer as we’ve had several days of over 100-degree weather. I like Canada Dry but became frustrated when everyone seemed to be out of it wherever I went. That’s when I decided to go it alone and make it myself.

    I tried another recipe first but it was way too sweet. With your recipe I held off on combining the rich simple syrup with the botanicals in case the ratio was off for our taste buds. After 72 hours of cold extracting I didn’t want anything to go to waste!

    After a bit of tinkering I made a mini-batch of 3/4 cup botanicals combined with 1/2 cup rich simple syrup. Seems perfect for us!

    Thank you so much for posting this. It’s truly delicious and a game-changer!

    Cheers!

    1. Marissa Stevens says:

      I love to hear this, Alec! I’m so happy to hear that you’re enjoying the recipe and making it your own!

  2. Fred says:

    Just wanted to know for the spices.. allspice, cardamom… do they need to be crushed?

    1. Marissa says:

      Hi, Fred. No need to crush them… Cheers!

      1. Fred says:

        Thanks!

  3. Fripi says:

    Hi, I made the tonic during the week, yesterday it was ready, I prepared a little batch of syrup.

    After reading all comment I had high hopes and was a little disappointed, but I think that the problem was the sparkling water… a newly opened san pelegrino bottle, but it lost it’s bubbles to quickly, so my G&T was a little bland, it was like gin diluted in water with bitterness… So next time I’ll try prerier and maybe a soda stream from a friend, it really needed more bubbles.
    Also my simple syrup wasn’t made with cane sugar, which is something that also give some flavor, so that’s my fault, I triedwith Erythritol which is a zero calories sweetener to use like sugar.

  4. Alex says:

    4 stars
    Hi all,
    I made some tonic water about three weeks ago for Christmas presents. Overall I loved it, next time I’ll adjust the ratios a bit and use less sugar syrup (it come out with a distinctly marmalade note!)

    However, since then all three of my jars have developed strange white clouds. Has anyone else experienced this? Are they now spoiled? They’ve been stored in the fridge. The taste is still fine – I drank some before realising.

    Thanks for anybody’s advice. Google is no help on this one!
    Alex

    1. Marissa says:

      Hi Alex. I haven’t had that happen and, honestly am not sure who to ask about it. Have a look at this article.

  5. Darren says:

    Hi, I’m really looking forward to trying your tonic, I’ve just made it and it’s in the fridge infusing, day 1… I was just thinking about the sugar syrup and that I do tend to drink sugar free tonic on the whole. Have you or anyone tried using a sugar substitute to make the syrup and if so did it work? I’ll probably give that a go with a part of the first batch in a few days. Thanks.

    1. Marissa says:

      Hi Darren. That’s so great! I hope you love it…On the sugar substitute, I honestly don’t know. I think you have the right idea about trying it with a small amount before adding it to the whole batch. Cheers!