“It's perfect for a hot summer day outside." —Lily, recipe tester, age 11
Cut 1 lime in half through both ends. Lay lime halves, flat side down, on cutting board, then cut each half crosswise into thin semicircles.
Add lime slices and sugar to large bowl. Use potato masher to mash sugar and lime slices together until sugar is completely wet, about 1 minute. Set aside.
Cut remaining 6 limes in half crosswise. Use citrus juicer to squeeze lime juice into bowl with sugar and lime slices.
Pour water into bowl and use rubber spatula to stir mixture until sugar is completely dissolved, about 1 minute.
Set fine-mesh strainer over large pitcher. Carefully pour mixture through strainer into pitcher. Use rubber spatula to stir and press on limes to get out as much juice as possible. Discard lime slices in strainer.
Carefully pour half of lime mixture into 2 ice cube trays. Place trays in freezer and freeze until frozen solid, 2 to 3 hours. Place remaining lime juice mixture in refrigerator.
When limeade cubes are frozen, pop them out of ice cube trays and add to blender jar. Pour remaining lime juice mixture over top.
For this recipe we wanted a drinkable frozen treat like Del’s Frozen Lemonade. We found that the best way to create a slushy frozen drink texture was to freeze half of our limeade mixture in ice cube trays and then blend it with the rest of the chilled liquid. Blending solid cubes with some liquid helps the cubes break down faster and create a slushy consistency. Another important factor in our slush-tastic drink? Sugar. The sugar in the limeade prevents it from freezing completely in the ice cube trays. And the slightly soft cubes are easier to blend into a slush!