1-First Step: Get your fruit and tools readyStart by cutting your seedless watermelon into cubes and making sure the seeds are out. You will need about 12 cups of cubed watermelon for this Cucumber Watermelon Mojito. Next, split the cucumber in half, setting one half aside for blending and the other half for slicing later. Pull out your blender, a fine strainer, a pitcher, and a serving spoon so everything is close at hand.This little bit of prep makes the rest of the process smooth and quick. If you are serving guests, this is also a fine time to chill your glasses or stash your pitcher in the fridge. Cold ingredients help the drink taste fresher and keep the ice from melting too fast.

2-Second Step: Blend the watermelon and cucumberPut the cubed watermelon and half the cucumber into the blender. Blend until the mixture looks smooth and juicy. Then strain the puree through a fine mesh strainer or sieve into a bowl or large measuring cup, pressing gently to get out the juice while leaving the pulp behind.This step gives your Cucumber Watermelon Mojito a smoother finish and keeps it from turning thick or slushy. You want the bright, fresh juice, not the fibrous bits. If you like a more rustic texture, you can strain less, but the classic version tastes cleaner and pours better.

3-Third Step: Add mint and limePour the strained juice back into the blender. Add the 1/2 cup fresh lime juice and the loosely packed mint leaves. Pulse just enough to mince the mint and mix everything together. You do not want to pulverize the mint into a paste, just wake it up enough to spread that fresh flavor throughout the drink.The lime keeps the sweetness in check, while the mint brings that unmistakable mojito taste. If you are making a mocktail version, this is the point where the flavor still shines even without the rum. For a stronger mint note, you can add a few extra leaves, but go easy so the drink stays balanced.

4-Fourth Step: Strain into a pitcher and stir in the rum and syrupStrain the minty juice into a pitcher. Add the 1/2 liter white rum and the 2/3 cup simple syrup, then stir well to combine. At this stage, your Cucumber Watermelon Mojito base should look bright, fragrant, and ready to chill. Cover the pitcher and refrigerate until you are ready to serve.This is also the best time to taste the base if you want to tweak the sweetness. A touch more syrup will make it friendlier for folks who like sweeter drinks, while a splash more lime will sharpen the flavor. If you are serving a mixed crowd, you can keep the base as-is and let each person adjust with more club soda later.

5-Final Step: Finish with fizz and garnishJust before serving, stir in the club soda and the sliced cucumber half. Pour the drink into ice-filled glasses so it stays cold from the first sip to the last. Top each glass with watermelon slices and mint sprigs if you like a pretty finish.The club soda should go in at the end so the bubbles stay lively. That little bit of fizz is what gives this Cucumber Watermelon Mojito its festive feel. For the freshest taste, serve right away once the soda is mixed in.