Put the sugar in a saucepan with 2 cups/500 ml water. Boil 5 minutes and add the ascorbic acid.
Slice the peaches (peeled if you prefer) into sterilized mason jars. Pour over the syrup to cover. Cook's Note: Don't fill to the top as the contents need space to expand as they freeze.
Freeze the jars.
Recipe courtesy of Laura Calder