Immediately pour the slushie into a clear glass serving bowl or a large glass pitcher. The texture should be thick and icy with a bright purple color.
Serve right away with a ladle and small glasses or cups. If it starts to melt, give it a quick stir to bring back the slushy texture.
For a sweeter slushie, use pink lemonade or a lemonade made from concentrate, or blend in 1–2 tablespoons of sugar or honey with the lemonade. For a more tart, grown-up flavor, use extra-lemony homemade lemonade and finish each glass with a squeeze of fresh lemon. To make it fizzier for parties, blend as directed, then gently stir in a splash of lemon-lime soda or sparkling water right before serving (do this in the bowl or pitcher, not in the blender, so it doesn’t foam over). For picky eaters who don’t like berry skins, blend the blueberries and lemonade first, then strain through a fine-mesh sieve before adding back to the blender with ice and blending again for a smoother texture. You can also swap in frozen mixed berries for a deeper purple color, or use half blueberries and half frozen strawberries for a brighter, more familiar flavor for kids. If you’d like a thinner drink instead of a thick slush, add an extra 1/2–1 cup of lemonade and blend again. For adults, you can turn this into a cocktail by adding a splash of vodka or white rum to individual glasses—keep the main batch alcohol-free so everyone can enjoy it. Food safety tips: Keep the lemonade and frozen blueberries cold until you’re ready to blend, and serve the slushie right away for the best texture and to avoid it sitting at room temperature too long. Discard any leftovers that have been out for more than 2 hours, especially at warm outdoor gatherings. Always rinse the outside of lemon containers or fresh lemons (if you’re using homemade lemonade) and wash your hands before preparing. Make sure your blender is in good condition and do not overfill it; blend in batches if needed to avoid spills or accidents.