Prep your produce. Peel the beet and ginger.
Chop the beet into small chunks so it blends easily. Cube the watermelon. If using a juicer, you can leave pieces a bit larger.
Choose your method: blender or juicer. For a blender, add watermelon, beet, ginger, lemon or lime juice, a pinch of salt, and 1/2 cup water.
For a juicer, run the beet, ginger, and watermelon through the machine, then stir in citrus juice and salt at the end.
Blend until smooth. Start on low, then increase to high for 45–60 seconds. If it’s too thick, add more water a little at a time. You want a pourable, juicy consistency.
Strain if you prefer a smoother sip. Pour the blended juice through a fine-mesh sieve or nut milk bag into a pitcher.
Press gently with a spoon to extract more liquid. Skip this step if you like some pulp.
Taste and adjust. Add more citrus for brightness, a touch more salt to enhance sweetness, or a few extra watermelon cubes if you want it sweeter.
Serve cold. Pour over ice, garnish with mint if you like, and enjoy immediately while it’s at peak freshness.