If you’ve ever wished your coffee had a fizzy edge, this recipe is your answer. Cold brew tonic combines smooth coffee with bubbly tonic water for a refreshing twist. Follow these simple steps to make your own barista-style drink at home
How to Make Cold Brew Tonic
The base here is cold brew coffee—smooth, low in acidity, and perfect for mixing. The details matter, from the beans to the tools, if you want it to taste great. It’s not hard, but a little attention goes a long way.
Equipment
You don’t need fancy gear. Grab a big glass jar or a French press for brewing and steeping. For straining, a mesh strainer or cheesecloth will do the trick.
If you’ve got a digital scale, use it for accuracy, but eyeballing works in a pinch. Stir things up with a spoon or stick to make sure all the grounds get wet. And, obviously, you’ll want a tall glass and plenty of ice for serving.
Burr grinders are great for a consistent coarse grind, but honestly, use what you have. Just keep your cold brew in a clean, airtight bottle in the fridge and it’ll stay fresh for several days.
Ingredients
Good water and decent beans make a difference. Go for filtered water and beans you actually like—medium or light roast tends to work best if you want something bright and nuanced.
Basic Cold Brew Recipe
- 80 grams (about 1 cup) coarsely ground coffee
- 1 liter (4 cups) filtered water
- Tonic water (chilled)
- Ice cubes
- Optional: Garnish (lemon, lime, or grapefruit peel)
If you can, pick beans with tasting notes that play well with citrus or herbal flavors. And use tonic water without artificial sweeteners—it really does taste better.
Instructions
It’s pretty hands-off, but you’ll need a bit of patience. Here’s how it goes:
- Combine ground coffee and water in your jar or French press.
- Stir so all the grounds get wet.
- Cover and let it steep—room temp or fridge—12 to 18 hours.
- Strain through mesh or cheesecloth into another container.
- To serve, fill a glass with ice, pour in 100 ml (about 3 oz) cold brew concentrate, and top with 100 ml (about 3 oz) tonic water.
- Garnish with citrus if you’re feeling fancy.
Keep the concentrate in the fridge; it’ll last up to a week.
Tasting Notes
This drink is crisp, refreshing, and just a little bit unexpected. The coffee brings mild chocolatey or nutty notes, while tonic water adds bubbles, gentle sweetness, and a touch of bitterness.
Depending on your beans and garnish, you might catch some floral, citrus, or herbal vibes. The aftertaste is clean, with that classic quinine zing from the tonic.
It’s not too sweet or acidic—just layered and interesting, especially if you start with good ingredients.
Quick Pro Tips
Go for a coarse coffee grind—otherwise, you’ll risk that bitter, over-extracted taste nobody wants. If you’re mixing cold brew with tonic, wait until the last second so the bubbles actually stick around.
Using a French press? Hold off on plunging until it’s time to filter; you’ll get a much cleaner cup. Honestly, don’t be afraid to mess with the coffee-to-water ratio until it tastes right to you.
Sometimes, tossing in a bit of lemon or even a slice of grapefruit brings a surprising brightness. And if you’re storing cold brew, glass bottles with tight lids are a must—unless you like your coffee with a hint of leftover takeout.
