Cut the watermelon into chunks using a large knife and cutting board, removing the rind if not already peeled. Ensure pieces are manageable for blending and look for ripe, fragrant fruit with a deep red interior.
Place the watermelon chunks into the blender. Secure the lid tightly to prevent splattering. Blend on high speed until the mixture is completely smooth and no large chunks remain, about 30-60 seconds. The color should be bright pink with a watery consistency.
Set a fine mesh strainer over a large bowl or pitcher. Pour the blended watermelon mixture through the strainer to separate the pulp from the juice. Use a spoon or spatula to press the mixture gently, extracting as much liquid as possible. Discard or compost the remaining pulp.
Pour the strained watermelon juice into glasses or a serving pitcher. Chill in the refrigerator for at least 15 minutes for a refreshing, cool beverage. Optionally, add ice cubes or a squeeze of lime for extra flavor.
Serve the watermelon juice chilled, garnished with mint leaves or a wedge of lime if desired. The final appearance should be clear, vibrant pink with a slightly thick, watery consistency that looks inviting and summery.
