In a medium saucepan, combine the water, sugar, and cranberries.
Heat until it comes to a boil, stirring occasionally, then simmer for 5-10 minutes. During the last minute or two of cooking, I add the zest of a few kumquats (it’s hard to get all of the zest off, obviously, so just a few swipes to release the essential oils) and then throw them in whole – they’ll permeate the syrup while cooling.
Remove from heat and let cool.
Strain into a glass jar and discard the cranberries/kumquats.