Watermelon Agua Fresca

My introduction to watermelon agua fresca has been nothing short of a revelation. 

In the past few weeks, watermelons have moved front-and-center at my local groceries. The fancy market and the “regular” one are both displaying huge boxes of melons as you walk in the door. And with good reason. When it gets hot, there is nothing like a cool slice of watermelon, except maybe a watermelon ice pop, a cup of watermelon chunks, or a watermelon-based drink.

So I played around with a watermelon version of the fruit drink called agua fresca and we’ll get to that in a minute. But first, a few watermelon basics.

Tips for Picking the Best Watermelons

• The best watermelons are symmetrical, free of bruises and have a creamy yellow spot where they sat as they ripened in the field.
• Relative to its size, the watermelon should be heavy. It is, after all 92% water. If it’s a large-size one, pick up a few and go for the heaviest. Even the “personal size” should be heavier than a soccer ball, even if they are the same size.
• Some people believe that you can hear a hollow sound if you thump a ripe watermelon. Personally, I’ve thumped quite a few and often can’t hear any difference between one watermelon and the next. Maybe a trained musician could hear the tones better than I can, but without one on my food shopping errands, I’ll leave thumping to others.

Watermelon Storage Tips

• Unlike bananas, watermelons do not ripen on your kitchen counter. If you buy one that is already ripe, you can leave it uncut on a counter, out of direct sunlight and in a reasonably cool location, for about 2 weeks.
• Once you’ve cut into a watermelon, it must be refrigerated. Cover the cut side or turn it down onto a plate or other container with a small rim to catch any juice that runs out.

Cutting watermelon

• Like all fruits and vegetables, even those with skin or rind that you cut off, a watermelon, should be rinsed under cool running water before you cut into it.
• A large serrated-edge knife works best.
• Cut the watermelon on a surface with a rim – I use a cutting board inside a rimmed baking sheet. Inevitably, at least a bit of juice will run out as you cut and this prevents a mess on your counter. I’m all about saving work cleaning up, after all.
• If you cut one end of the watermelon to flatten it, the melon won’t slip as you cut more. Then after cutting the melon in half, you can easily slice off the rind.

Agua fresca is popular in Mexico and other countries south of the U.S. Incredibly refreshing and light, it stars one or more summer fruits blended with water or seltzer. Many versions include extra sweeteners, such as honey or simple syrup (sugar dissolved in water), but it turns out that it isn’t necessary to add any of them as long as you expect the drink to taste of fruit and not like a commercially prepared soda.

I found that trick to making great agua fresca is to start with a low ratio of fruit to water or soda and then add more of the fruit until you get the taste you like. On the advice of my Mexican cooking maven, Pati Jinich, author of Pati’s Mexican Table: The Secrets of Real Mexican Home Cooking, I began with a 1-to-1 ratio of watermelon to water. (This advice runs counter to lots of recipes that start much more fruit and add a sweetener. But I’m comfortable following my own path, especially when the result is this good.) I added more watermelon until I got to a 2-to-1 ratio, switched to seltzer instead of water, and added mint and lime – eureka! My taste testers loved it and I’m planning to make this watermelon agua fresca frequently during the upcoming hot months.

Watermelon Agua Fresca

Servings – 4 small glasses (5 ounces each)   Cost – $3

Ingredients

• 16 ounces of watermelon. You may opt for slightly more, depending on the flavor and sweetness of your watermelon. Measurement by weight is more accurate than by volume (e.g. cups), because the volume measurement changes depending on how small you cut the chunks. In general, if you cut 1-2″ cubes, 16 ounces equals about 3 cups.
• 8 ounces of seltzer
• 4 slices of lime (½ – ⅔ of a lime)
• 4-8 fresh mint leaves

Equipment

• Cutting board
• Rimmed baking sheet
• Large serrated-edge knife
• Small knife (for cutting the lime)
• Blender or food processor
• Large pitcher or measuring cup
• Strainer
• Spoon
• Mortar and pestle, a mallet, or a large spoon

Preparation

• Cut the watermelon into chunks.

• Place the chunks in a blender or food processor with half (4 ounces) of the seltzer. (In a blender like mine, you can’t chop the watermelon without at least a small amount of liquid.) If you don’t have a blender or food processor, you can even use a potato masher or similar implement – it will just take more time and elbow grease.
• Blend the melon until it is thoroughly puréed (mushed up.)
• Strain the mixture into the pitcher or large measuring cup, pressing any watermelon “flesh” left in the strainer with a spoon until all the juice comes out. Discard the flesh.

• Slice the lime and “muddle” the mint leaves slightly with a mortar and pestle or by pressing the leaves with the back of a spoon. In bartender talk, muddling means to smush slightly, which releases the mint essence from the leaves.

• Add the remaining seltzer (about 4 ounces), pour the agua fresca into glasses, and garnish with the lime and mint. If you want more volume in the glass and like your drinks cold, add ice cubes or a large spoonful of crushed ice.

Disclosure – This post is part of a series sponsored by the National Watermelon Promotion Board. All opinions expressed and all editorial decisions are my own.