Wash 6 limes thoroughly, then cut them into quarters on a cutting board.

Remove the white center membrane and seeds from the lime quarters to reduce bitterness.

Blend the prepared lime quarters with 1 l of water for 10 seconds only.

Strain the blended lime mixture into a mixing bowl, pressing lightly to remove pulp while avoiding excess bitterness.

Pour the strained lime liquid back into the blender and add 2 cups of ice.

Add 3/4 cup sweetened condensed milk, then blend until smooth and creamy.

Add up to 1 additional cup of water if a thinner lemonade consistency is desired.

Combine organic sugar and lime zest in a mixing bowl.

Moisten the rims of 4 serving glasses and coat them with the lime-zest sugar mixture.

Pour the creamy lemonade into the prepared glasses and garnish each serving with a maraschino cherry.