Maybe when you were younger, in college say, did you ever take a watermelon, cut a hole in the top, then proceed to upturn a whole bottle of vodka into that hole? Once that bottle of vodka had emptied itself into the watermelon, you plugged it back up then put it in the fridge for a couple of days. When your 20 or 30 friends showed up at your pool a few day later, everyone got to enjoy slices of boozy, cold fruit. Because it was so fruity and refreshing, those slices went down fast and lethal. Now that I'm a grown woman, I like to think that I have moved beyond those years and can drink with a little bit more sophistication. Now, I blend the watermelon and vodka and put it in a glass. See the difference?
What makes this a cooler?
A Cooler is just a category of cocktails where you mix a wine or liquor with fruit juice, then pour over ice in a tall glass and top with sparkling water. Unlike a Collins, you're not adding any simple syrup, so you have to rely on your fruit juice for the sweetening of your drink. You can be very creative with the combinations. Pineapple juice and rum? Blueberry and gin? As long as it's tall, cold, fruity and sparkling, it should work.
Watermelon Vodka Cooler
1/2 cup watermelon juice (start with 2 cups watermelon, cubed and seeded)
1 1/2 oz vodka
1/2 oz sweet vermouth
juice of 1/2 lime
club soda & ice
I don't own a juicer, so I have to juice my watermelon by using a blender. In my case, I used an immersion blender. Just put your chunks of watermelon in a bowl (without seeds!) and give it a whirl.
You can just use it with the delicate pieces of watermelon pulp still in it or pour it through a sieve to just get the juice. Personally, I like the pulp. Using a 1/4 of a small seedless watermelon, I got about 2 cups of watermelon juice.
Now, in a tall glass, put in plenty of ice. Add your vodka and sweet vermouth. Squeeze in your lime juice. Over this, pour about 1/2 cup of the watermelon juice, then top with club soda. Give it a good stir. Garnish with a small lime wedge or some fresh mint.
Now, go sit on the front porch and enjoy that first long day of summer. Cheers!
p.s. if you really want to go old-school on the watermelon and vodka, here is a tutorial video that shows you how to make a drunken watermelon.