Watermelon-Mint Shrub with Watermelon Spoom

Ingredients

• For the shrub:
• 3/4 cup sugar
• 3/4 cup water
• 3 cups puréed, strained watermelon
• 2 tablespoons fresh juice from about 2 limes
• 3/4 cup plus 2 tablespoons rice wine vinegar
• For the mint syrup:
• 1 cup sugar
• 1 cup water
• 1/2 cup chopped fresh mint leaves
• For the pickled rind:
• Rind from 1/2 medium watermelon
• 1 cup champagne vinegar
• 2 packets unsweetened watermelon Kool Aid
• 1 1/2 cups sugar
• For the spoom:
• 3 cups watermelon purée
• 2/3 cup water
• 3 egg whites
• Pinch salt
• 1/2 cup sugar

Directions

1. In a small saucepan, stir together the sugar and water and bring the mixture to a boil. Let it boil just long enough for every sugar crystal to disappear, then set it aside until it has cooled completely. Once it’s cool, mix it with the watermelon purée, lime juice, and vinegar. Spoon off any foam sitting on top, then cover it and let it sit in the refrigerator for at least 2 days.
2. In a small saucepan, combine the sugar and water. Bring it to a boil and cook until the sugar has dissolved. Stir in the mint, lower the heat, and let it simmer for 1 minute. Take the pan off the heat, cover it, and leave it to steep for 30 minutes. Strain out the mint and throw it away, then chill the syrup thoroughly before you use it.
3. Peel away the green skin from the outside of the watermelon rinds. Cut off any leftover pink flesh on the inside, along with any extra-tough rind on the outside. Slice what’s left into 1/4-inch planks, then use a cookie cutter or knife to cut them into small decorative shapes. In a medium saucepan, combine the water, vinegar, Kool-Aid, and sugar and bring the mixture to a simmer. Add the watermelon rind and simmer for 30 minutes. Strain the rind into a heat proof container, then keep simmering the liquid until it has reduced by about a third, around ten minutes. Pour the reduced liquid over the rind, let it cool to room temperature, then cover and refrigerate for at least 24 hours.
4. Mix the watermelon purée and water together. With a stand mixer or electric handheld mixer, beat the egg whites with the salt on medium-high speed until they’re foamy, then add the sugar and beat on high speed until you have glossy, firm peaks. Pour the watermelon purée into the meringue and fold it in with a whisk. Don’t worry when it refuses to behave like most meringue mixtures; just keep going. It will turn into a pale pink, slightly fluffy, thick liquid. Freeze it in an ice cream maker according to the manufacturer’s instructions, then transfer it to a sealed container and let it firm up in the freezer for at least 4 hours before scooping.
5. For a 10 ounce glass, stir together 1/4 cup shrub and 1 tablespoon mint syrup. Fill the glass with ice, pour in the shrub mixture, and top it with still or sparkling water. Add a few pieces of pickled watermelon rind, give it a gentle stir with a straw, and serve it with watermelon spoom.