Step 1: Prepare Watermelon: Cut your watermelon into 1-inch cubes. For the best results, freeze at least 4 cups of these cubes for a minimum of 4 hours, or preferably overnight. Keep 1 cup fresh for easier blending if needed, or freeze all 5 cups.
Step 2: Combine Ingredients: In a high-speed blender, combine the frozen watermelon cubes, lime juice, and your chosen sweetener. Start with 1 tablespoon of sweetener and add more later if desired. The amount will depend on the sweetness of your watermelon.
Step 3: Add Ice and Blend: Add 1-2 cups of ice cubes to the blender. The amount of ice depends on how frozen your watermelon is and your desired consistency. Start blending on low, then increase to high speed.
Step 4: Achieve Slushie Consistency: Use your blender’s tamper (if available) or stop and stir (ONLY when the blender is off!) to push the ingredients towards the blades. Continue blending until the mixture is completely smooth and has a thick, icy slushy consistency.
Step 5: Taste and Adjust: Taste the slushie and adjust sweetness with more honey/agave or add another squeeze of lime juice for extra tang. If it’s too thick, add a tablespoon of cold water at a time and re-blend. If it’s too thin, add a few more frozen watermelon chunks or ice cubes and blend again.
Step 6: Serve: Pour the refreshing watermelon slushie into chilled glasses. Garnish with a fresh lime wedge or a small slice of watermelon. Serve immediately and enjoy!