Blend the watermelon
Add 6 heaping cups of chopped watermelon to the blender and blend on high until smooth. Work in batches if your blender is small. I always taste a spoonful to make sure the melon tastes juicy and sweet.
Strain (for best clarity)
Place a nut milk bag over a large bowl and pour the blended watermelon into the bag. Gently squeeze the liquid out and discard the remaining pulp. You’ll end up with bright, clear watermelon juice — so pretty.
Juice the limes
Juice 3 limes and keep the juice ready. Save a few lime slices for garnish.
Build each spritzer
In each glass add: 1 oz vodka, 1/4 cup watermelon juice, and 2 tablespoons lime juice. Stir to combine. If you skip alcohol, simply increase watermelon juice a bit and you’ve got a refreshing mocktail.
Top, ice, and enjoy
Add ice cubes and top with plain seltzer (roughly 3–4 oz per glass depending on desired fizz). Garnish with a lime slice and serve immediately.