Begin by washing the limes thoroughly under cool running water. Next, slice each lime into quarters to maximize juice extraction. Set the quartered limes aside, ready for blending.

In a blender, combine the quartered limes with 4 cups of water. Secure the lid and blend on high for about one minute, or until the limes are fully liquefied.

Using a fine mesh sieve, strain the blended mixture into a large bowl. Gently press down on the pulp with a spatula to extract as much juice as possible.

Pour the strained lime juice back into the blender and add the remaining 2 cups of water, granulated sugar, and sweetened condensed milk. Blend on low for one minute until combined.

Fill tall glasses with ice, pouring the Brazilian Lemonade over it to chill. Garnish each glass with a slice of lime.