6 Tbsp. sweetened condensed milk
Make a “simple syrup” or “sugar water” by mixing cold water and sugar in a large jar or liquid measuring cup very well until sugar is dissolved. Chill until ready to use. (This step can be done ahead of time.)
Wash limes thoroughly with soap. Cut the ends off the limes and then cut each lime into 8ths.
Place 1/2 of the limes in a blender.
Add 1/2 of the sugar water into a blender, place the lid on the blender, and pulse 5 times. Place a fine-mesh strainer over a pitcher and pour the blended mixture through the strainer and into the pitcher. Use a spoon (or your hand) to press the rest of the liquid into the pitcher.