Coconut Cold Brew Tonic: The 3-Ingredient Summer Coffee Drink You Need

By PURE EARTH COFFEE  ·  May 13, 2026  ·  Coffee Recipes

Why It Works

Cold brew's low acidity and natural sweetness make it an ideal partner for carbonated mixers. The tonic water adds bitterness and effervescence. The coconut water adds a subtle sweetness and electrolyte quality without the heaviness of milk or cream. Together they create something that reads as refreshing the way a really good sparkling water does — light, crisp, and layered.

The key is using high-quality tonic water. Cheap supermarket tonic is too sweet and will dominate. Look for a premium tonic with real quinine bitterness — Fever-Tree, Q Mixers, or similar.

Ingredients (Serves 1)

• 90ml cold brew concentrate
• 90ml premium tonic water
• 60ml unsweetened coconut water
• Ice, a wedge of lime, a sprig of mint (optional)

Make it with our cold brew guide

How to Make It

Step 1 — Build Over Ice

Fill a tall glass with ice. Pour the cold brew concentrate over the ice first.

Step 2 — Add Coconut Water

Pour the coconut water over the cold brew. Stir gently once to combine.

Step 3 — Top With Tonic

Pour the tonic water slowly over the back of a spoon to preserve as much carbonation as possible. Do not stir after this — you want the bubbles to stay active through the first few sips.

Step 4 — Garnish and Serve

Squeeze a lime wedge over the top and drop it in. Add a sprig of mint if you have it. Serve immediately.

Variations

Salted version: Add a pinch of flaky sea salt before the tonic — it suppresses bitterness and amplifies the coconut sweetness. Spiced version: Add a small splash of cardamom simple syrup. The cardamom plays beautifully with coconut. Boozy version: Add 30ml of white rum or coconut rum before the tonic. You have just made a coffee cocktail worth serving at any summer gathering.

Cold Brew Tips for This Recipe

Because the tonic and coconut water are relatively light, the cold brew needs to anchor the drink. Use a concentrate: 1 cup of coarsely ground coffee to 2 cups of water (rather than the usual 4), steeped 18–24 hours. This gives you a cold brew that does not disappear into the mixer.

Three ingredients. Five minutes. Make it this weekend.