Wash the kumquats. Pierce each kumquat a couple of times, with a fork.

Place pierced kumquats in a large pot, and pour sugar on them. Cover, and let stand 10-12 hours, or overnight.

Bring the fruit mixture to a boil, remove from heat and let cool.

Return to the heat, and bring to a boil once again. Remove from heat and let cool.

At this point, the jam is supposed to be ready. You can check by taking some liquid out with a teaspoon and smearing it on a cold plate. If the doesn't spread all over the plate and stayed in a straight line, the jam is ready. If not put the pot back on medium heat and wait until liquid solidifies to jelly texture.

Store jam in sterilized Cannes while still warm.