Use to make Candied Kumquat Tartlets.
Place sugar in a medium saucepan and add 2 cups water. Bring to a boil over medium-high heat; cook, stirring occasionally, until sugar has dissolved. Reduce heat to a simmer and add kumquats; let simmer for 1 hour. Carefully remove kumquats from liquid and place in an even layer on a wire rack, set over parchment paper, to dry, at least 4 hours and up to overnight.