This small oval fruit, with its sweet-and-sour characteristic, is a member of the citrus family and perfect to preserve as it is edible in its entirety.
Cut the cumquats in half and remove the seeds. Put the seeds in a muslin bag and tie up.
Weigh the cumquats, put them in a bucket, cover with water and refrigerate overnight.
Transfer the cumquats, water and seeds to a large, heavy-based stockpot and add sugar to half the weight of the cumquats. Bring the stockpot to a boil and simmer for 1 hour. Turn of