Cut the kumquats into quarters or slices. Fill a large pitcher with (ice) water and add the kumquats.
Place the pitcher in the refrigerator for a while to allow the flavour to infuse the water.
You can also use sparkling (carbonated) water.
Tip 2: You can also make ice cubes with kumquats in them beforehand. Halve the kumquats and put one half in each square or round of an ice cube tray. Fill with water and carefully place in the freezer.