Watermelon jelly with vodka in a watermelon rind

Ingredients:

• 1 small seedless watermelon (about 2.3 kg)
• 2 x 80g packets of watermelon-flavored jelly mix, such as Jell-O
• 3 packets of 7 grams of gelatin
• 1 teaspoon granulated citric acid
• 1 tbsp. (240 ml) vodka

Preparation:

1. Using a large chef's knife, cut the watermelon in half lengthwise. Trim a piece from the convex part of each half to ensure they sit stable and don't wobble. Place the watermelon halves on a rimmed baking sheet. Scoop most of the flesh out with a large spoon into a bowl, leaving about 0.3 cm of flesh above the white part of the rind (this will help the jelly set).
2. Transfer the watermelon pulp and any juices from the bowl and rind to a blender and blend until smooth, about 2 minutes. Strain through a fine-mesh sieve lined with cheesecloth (or a coffee filter). Discard the solids and set aside the juice; you should have about 5 cups of juice.
3. Pour 3 cups of juice into a medium saucepan (reserve the remaining juice for another use). Bring to a boil over medium-high heat.
4. Meanwhile, in a large bowl, combine the gelatin with the jello mixture and citric acid. Then add the hot watermelon juice and stir until the gelatin dissolves, about 2 minutes. Stir in the vodka. Pour the gelatin mixture into the watermelon rinds. Refrigerate until completely set, about 4 hours and up to 24 hours.
5. Cut the watermelon in half lengthwise, then crosswise into small wedges. Serve chilled.
   
   Note
   
   If you are making dessert for children, replace the vodka with 1 cup of remaining watermelon juice.