In a small pot, combine ½ cup of white sugar and ½ cup of water over medium heat. Stir continuously until the sugar fully dissolves and the mixture is clear, taking about 3-5 minutes. Remove from heat and let it cool completely.

Rinse 22 calamansi limes under cool water, then slice each in half. Using a citrus juicer, squeeze the juice into a sieve placed over a bowl to catch seeds.

In a pitcher, combine the freshly squeezed calamansi juice with ⅔ cup of cold water. Stir well to combine.

Gradually add ¼ cup of the prepared simple syrup, mixing and tasting as you go to achieve the ideal sweetness.

Pour the mixture into a glass filled with ice cubes, and add a slice of calamansi or a sprig of mint for an extra touch.