Watermelon Mint Cooler Slush
By Marty Cole · March 30, 2026
5.0 (1)
Had half a watermelon going soft on the counter and didn't want to waste it, so I strained the juice, hit it with fresh lime and a little simple syrup, and ran it through the Ninja Slushi. This Watermelon Mint Cooler Slush tastes like the inside of a watermelon got frozen at the exact right second, light and not too sweet. Strain the juice well or the pulp makes it grainy instead of smooth. My neighbor came over to return a ladder and left with a full cup and zero ladder.
Your machine size
Slushi 64 oz (Standard) · quantities scaled ×1
Ingredients
- Strained Watermelon Juice44 oz
- Fresh Lime Juice2 tbsp
- Simple Syrup3 oz
- Fresh Mint Leavesoptional6 garnish
Makes ~52 oz
Directions
- 1Blend watermelon cubes and strain out the pulp to get smooth juice.
- 2Stir in the lime juice and simple syrup until fully dissolved.
- 3Pour the chilled juice into the Slushi vessel, not past the max line.
- 4Lock the lid and run the SLUSH preset.
- 5Let it freeze until thick and icy, up to 40 minutes.
- 6Serve over a few muddled mint leaves for fresh aroma.
Tips
- Pour your strained watermelon juice, fresh lime juice, and simple syrup directly into the Slushi bowl at the start, making sure not to overfill past the max line
- Check on your slush every 10-15 minutes starting around the 20-minute mark; it's ready to scoop when it reaches a thick, granita-like consistency
- If your slush feels too icy or separated, let it churn for another 5-10 minutes to help the machine re-incorporate everything into a smoother texture
Variations
- Swap half the watermelon juice for fresh strawberry juice for a pink-hued cooler with a berry note
- Add a small splash of white rum or vodka to your liquid base for an adult version, then pour the whole mixture into the bowl as usual
FAQ
- Can I use bottled watermelon juice instead of fresh?
- Yes, bottled juice works fine as long as it's 100% juice with no added sugar or thickeners. Strain it one more time to remove any pulp that could clog the machine.
- What if my slush won't freeze solid or is too slushy?
- The Slushi works best when your kitchen is cool and the machine runs uninterrupted. If it's not freezing enough after 45 minutes, your base liquid may be too warm or the room temperature is too high, so try starting over with chilled ingredients.
- Can I make this less sweet?
- Cut the simple syrup by one third or one half and adjust the lime juice up slightly for more tartness. You can always pour the slush out, mix in more lime juice, and run the machine again for 10 minutes to blend it in.
- How long does the finished slush keep?
- A finished slush stays scoopable in the Slushi bowl for about 1-2 hours before it starts to refreeze into a solid block. For longer storage, transfer it to an airtight container in the freezer.
Nutrition
Per serving · makes about 4 servings · estimated
Ratings & Reviews
5.0 (1)- Jason X
This was great!!
Jun 26, 2026
Meet Marty Cole
I'm a home cook who got a little obsessed with the Ninja Slushi and Creami. I test every recipe in my own kitchen on a real machine, dial in the texture, and only post the ones my family actually finishes.
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