Watermelons were a dollar a kilo at the fruit shop on Beaumont Street last Thursday, and I bought three because that’s what you do when they’re that price. One went into a salad with feta, one got eaten straight off the board standing at the bench, and the third became this. A watermelon mint cooler isn’t complicated and I’m not going to pretend it is, but there’s a right way to do it and a lazy way, and the lazy way tastes like sweet water with a leaf floating in it.
Why watermelon mint cooler actually works
Watermelon is over ninety percent water, which sounds like it should make for a thin, forgettable drink. It doesn’t, because ripe watermelon carries real sweetness alongside that water content, and mint does something clever to it: the menthol cools the palate on the way down while the sugar’s still doing its job on the way in. Add a squeeze of lime and you’ve got acid cutting through the sweetness so it doesn’t sit heavy. That’s the whole trick. Three elements, each one doing a different job, none of them fighting.
I’d argue most bottled versions of this get the balance wrong by going too sweet and skipping the acid altogether, which is why they taste flat after the first mouthful. You won’t have that problem here because you’re tasting the fruit itself, not a syrup standing in for it.
Picking and prepping the watermelon properly
Don’t muck about with a watermelon that sounds hollow and light when you knock on it. You want one that feels heavy for its size, with a dull skin rather than a shiny one, and a creamy yellow patch where it sat on the ground ripening. That yellow patch, called the field spot, is the single best indicator you’ll get without cutting into it.
Skip the pre-cut tubs from the supermarket chiller if you can help it. They’re usually cut from fruit that was picked underripe so it’d survive transport, and by the time it’s sitting in that plastic tub under lights it’s gone soft and lost most of the flavour it had. A whole watermelon cut fresh at home, chilled properly beforehand, will run rings around it every time.
Chill the whole melon in the fridge overnight before you start. This isn’t fussy, it’s just physics: a cooler starting temperature means less ice needed later, and less ice means less dilution of the flavour you’ve worked to get right.
Ingredients
- 800g seedless watermelon, deseeded and cubed, well chilled
- 15 fresh mint leaves, plus extra sprigs to serve
- Juice of 1 lime
- 1 teaspoon honey (optional, only if your melon isn’t sweet enough)
- A small pinch of sea salt
- 250ml chilled soda water or coconut water
- Ice, to serve
Method
- Get your watermelon properly chilled the night before. This is the one step people skip and it makes more difference than anything else on this list.
- Put the watermelon cubes, mint leaves and lime juice into a blender. Blend on high for about 30 seconds, until smooth.
- Taste it. If the melon’s a touch underripe or tart, stir through the honey now. Add the salt – it sounds odd in a fruit drink but it sharpens the sweetness rather than making it taste salty.
- Strain through a fine sieve if you want it silky, or leave it with a bit of pulp if you don’t mind some texture. I go about halfway, straining once through a coarse sieve and leaving it at that.
- Fill four glasses with ice, pour the watermelon mixture over to about two-thirds full, then top each glass with soda water or coconut water and give it one gentle stir.
- Garnish with a mint sprig and drink it straight away. This one doesn’t hold in the fridge – the fizz drops and the colour separates within about twenty minutes.
Serves: 4
A decent way to serve it
This works best as an afternoon drink rather than a breakfast one: the natural sugars in watermelon hit faster on an empty stomach than most people expect, so I’d have it alongside something rather than instead of a meal. It’s a good match for anything off the barbecue, particularly the whole fish with coriander I do most weekends through summer, where you want something cold and clean between mouthfuls rather than another beer. I’ve also served small glasses of it as a palate cleanser between courses at a longer lunch, which felt a bit much the first time I tried it and worked better than I expected.
A variation worth trying
Swap half the watermelon for cucumber and you get a greener, less sweet version that leans more savoury – good with a pinch of Ceylon cinnamon dusted over the top, oddly enough. My mint’s gone feral in the garden bed this year, taken over half the herb patch and most of the thyme’s territory along with it, so I’ve been finding reasons to use it in everything. This is one of the better ones. If you want something with a bit more electrolyte value for after a run or a hot afternoon in the yard, a splash of coconut water instead of soda gets you there without turning it into a sports drink.
Where this sits if you’re watching fluids generally
Watermelon’s water content makes drinks like this a genuinely useful part of staying on top of fluids through an Australian summer, though it’s not a replacement for water itself, and I wouldn’t want anyone reading this thinking a glass of this counts the same as plain water on a stinking hot day. I’ve written more on that over on the staying hydrated in Australian summer piece if you want the fuller picture. The CSIRO’s dietary guidance and the Eat for Health guidelines both note that fruit like watermelon contributes to your daily fluid and fruit intake, but they’re not suggesting you swap out water altogether, and neither am I.
If you like this style of thing, the beetroot and apple juice I run through most weeks is worth a look too, and there’s a whole run of similar drinks over in the drinks category. For anyone trying to get more fruit and veg into the week without overhauling everything, the piece on eating more plants without a meal plan covers that ground properly.
Three watermelons for three dollars was a good week. This cooler’s the reason the third one didn’t just get eaten off the chopping board like the other two.
– Dave Forsythe, Golden Door Living kitchen
