Rosemary-Grapefruit Sparkling Cooler

Quick Recipe Version (TL;DR)

• Yield: 2 drinks (about 12 fl oz each)
• Prep Time: 10 minutes
• Cook Time: 5 minutes
• Total Time: 25 minutes (includes cooling time)

Quick Ingredients

• 1/2 cup (120 ml) water
• 1/2 cup (100 g) granulated sugar
• 2 small sprigs fresh rosemary (about 4 in / 10 cm each)
• 1 cup (240 ml) freshly squeezed grapefruit juice (ruby or pink)
• 3 tbsp (45 ml) rosemary syrup (from above), or to taste
• 1 1/2 cups (360 ml) chilled sparkling water (unsweetened)
• 1 cup ice cubes
• Extra rosemary sprigs and grapefruit slices for garnish
• Small pinch fine sea salt (optional, but recommended)

Do This

• 1. Simmer water, sugar, and rosemary for 3–5 minutes until sugar dissolves; remove from heat and steep 10 minutes, then strain and cool.
• 2. Juice grapefruits to get 1 cup juice; strain if you prefer a smoother drink.
• 3. In a small pitcher, stir together grapefruit juice, 3 tbsp cooled rosemary syrup, and a tiny pinch of sea salt.
• 4. Fill two tall glasses with ice.
• 5. Divide the grapefruit-rosemary mixture between the glasses, filling each about halfway.
• 6. Top each glass with chilled sparkling water, stirring gently to combine without knocking out all the bubbles.
• 7. Garnish with a small rosemary sprig and a slice or wedge of grapefruit; serve immediately while very cold and fizzy.

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Why You’ll Love This Recipe

• Bright, refreshing citrus layered with cozy herbal rosemary notes for a grown-up, not-too-sweet cooler.
• Uses simple ingredients you can find anywhere: fresh grapefruit, rosemary, sugar, and sparkling water.
• Easily scaled up for a pitcher, and simple to make ahead by prepping the rosemary syrup in advance.
• Perfect as a non-alcoholic sipper, but can be turned into a cocktail with a splash of gin, vodka, or tequila.

Grocery List

• Produce: Ruby or pink grapefruits (2–3 medium), fresh rosemary (1 small bunch)
• Dairy: None
• Pantry: Granulated sugar, sparkling water (unsweetened), ice, fine sea salt (optional)

Full Ingredients

Rosemary Simple Syrup

• 1/2 cup (120 ml) water
• 1/2 cup (100 g) granulated sugar
• 2 small sprigs fresh rosemary, about 4 in / 10 cm each (plus extra for garnish)

Rosemary-Grapefruit Sparkling Cooler (2 Servings)

• 1 cup (240 ml) freshly squeezed grapefruit juice (from about 2 medium grapefruits)
• 3 tbsp (45 ml) cooled rosemary simple syrup, or more to taste
• 1 1/2 cups (360 ml) very cold sparkling water, club soda, or seltzer (unsweetened)
• 1 cup ice cubes (or more, to fill the glasses)
• Small pinch fine sea salt (optional, enhances flavor)
• 2 thin grapefruit slices or wedges, for garnish
• 2 extra small rosemary sprigs, for garnish

Step-by-Step Instructions

Step 1: Make the rosemary simple syrup

Add the water, sugar, and rosemary sprigs to a small saucepan. Set over medium heat and bring just to a gentle simmer, stirring occasionally until the sugar is completely dissolved, 3–5 minutes. You do not need a rolling boil; a few small bubbles and steam are enough.

Once the sugar has dissolved and the mixture looks clear, remove the pan from the heat. Leave the rosemary sprigs in the hot syrup to steep and infuse their flavor for about 10 minutes. The longer you steep, the stronger and more piney the rosemary note will become.

Step 2: Strain and cool the syrup

After steeping, remove and discard the rosemary sprigs. Strain the syrup through a fine-mesh sieve into a heat-safe jar or small bowl to catch any loose rosemary needles. Let it cool to room temperature.

For faster chilling, set the jar in a shallow bowl of ice water and stir occasionally until cool. Once cooled, the syrup should be slightly thickened and clear. You will have more than you need for two drinks; store the extra in the refrigerator for the next round.

Step 3: Juice the grapefruits

While the syrup cools, roll each grapefruit firmly on the counter with your palm to help release the juice. Cut them in half and juice them using a citrus juicer or reamer until you have 1 cup (240 ml) of juice.

If you prefer a smooth drink with no pulp, strain the juice through a fine-mesh sieve into a measuring cup. If you like a bit of texture, you can skip the straining or only strain out larger bits.

Step 4: Mix the grapefruit-rosemary base

In a small pitcher or large measuring jug, combine the 1 cup grapefruit juice with 3 tbsp (45 ml) of the cooled rosemary syrup. Add a small pinch of fine sea salt, if using. The salt does not make the drink salty; it simply rounds out the bitterness of the grapefruit and brightens the citrus flavor.

Taste the mixture. If you prefer a sweeter drink, stir in an extra 1–2 tsp of syrup at a time until it hits the balance you like. Remember that the sparkling water will slightly dilute the sweetness, so it is fine if this base tastes just a touch sweeter than you want the final drink to be.

Step 5: Prep the glasses with ice and garnish

Fill two tall glasses (10–12 oz / 300–350 ml capacity) with ice cubes. Thinly slice a few rounds or wedges of grapefruit for garnish. Rinse two small rosemary sprigs under cool water and gently pat dry. Lightly bruise the rosemary by pressing or rolling it between your fingers; this helps release the aromatic oils so you smell the rosemary with every sip.

Step 6: Add sparkling water and serve

Give the grapefruit-rosemary base a quick stir, then divide it evenly between the two ice-filled glasses, filling them about halfway. Top each glass with 3/4 cup (180 ml) of very cold sparkling water. Stir gently from the bottom up just once or twice to combine without knocking all of the bubbles out.

Garnish each glass with a rosemary sprig and a grapefruit slice perched on the rim or slipped down the side of the glass. Serve immediately while the drink is icy cold and sparkling. Sip and adjust to taste with a splash more sparkling water (for lighter flavor) or a drizzle more syrup (for extra sweetness), if desired.

Pro Tips

• Chill everything first. For maximum fizz and refreshment, refrigerate the grapefruit, syrup, glasses, and sparkling water before making the drink.
• Control the rosemary strength. A 10-minute steep gives a noticeable but gentle herbal flavor; for a stronger hit, steep up to 20 minutes, tasting as you go.
• Balance bitterness and sweetness. Grapefruits vary in bitterness and sweetness. Always taste the grapefruit-rosemary base and tweak syrup or a tiny extra pinch of salt until it is just right for you.
• Use good sparkling water. A crisp, neutral sparkling water or club soda (unsweetened) lets the grapefruit and rosemary shine without adding off flavors.
• Make it pretty. A thin grapefruit wheel tucked against the glass and a tidy, upright rosemary sprig make this simple drink look special enough for guests.

Variations

• Boozy rosemary-grapefruit spritz: Add 1–1 1/2 oz (30–45 ml) gin, vodka, or blanco tequila to each glass before topping with sparkling water. Gin pairs especially well with the rosemary.
• Honey-rosemary version: Replace the granulated sugar with 1/2 cup (170 g) mild honey in the syrup. Warm gently until the honey dissolves, then proceed as directed for a richer, more floral sweetness.
• Less-sugar, more-bitter cooler: Use only 2 tbsp (30 ml) syrup, add a splash (1–2 tbsp) extra plain sparkling water, and garnish with an additional grapefruit peel twist for more aromatic bitterness.

Storage & Make-Ahead

The rosemary simple syrup can be made well in advance. Store it in a clean, tightly sealed jar in the refrigerator for up to 2 weeks. The flavor may intensify slightly over time. Freshly squeezed grapefruit juice is best used the same day, but it can be refrigerated in a covered container for up to 24 hours.

For easy entertaining, you can mix a larger batch of the grapefruit-rosemary base (juice + syrup + pinch of salt) up to 1 day ahead and keep it chilled in the refrigerator. Right before serving, pour the base over ice in a pitcher or individual glasses and top with sparkling water so the drink stays fizzy. Once the sparkling water is added, the cooler is best enjoyed within 20–30 minutes.

Nutrition (per serving)

Approximate values per 1 drink (without alcohol): about 120 calories; 0 g fat; 0 g protein; 30 g carbohydrates; 29 g sugars; 0 g fiber; 5–10 mg sodium. Actual values will vary based on the exact sweetness of your grapefruits and how much syrup you use.