Put the kumquats into a pot and cover with water and add the salt. Bring to a simmer.

Strain the kumquats. Add the kumquats, sugar, corn syrup (if using) and enough water just to cover the fruit. Simmer on medium low until the syrup is the consistency of honey.

Pour into a Jar and allow it to cool. The kumquat marmalade with thicken as it cools. It can be refrigerated for a week.