The variety of citrus fruit used in this recipe gives the cordial a lovely taste. It was Frances Bissell's idea.
Bring the sugar and the water to the boil. Add the flowers and bring back to the boil. Turn off the heat. Slice the citrus fruit as thin as you possibly can and put the lot in a suitable plastic container. Dissolve the acid in a little water and add to it together with the boiled mixture. Cover the container and leave for about one day; now and again press the mixture with a wooden spoon. Bottle or freeze in portions. Note that if you thoroughly rinse the solids at the bottom of you container , after bottling, a nice portion of ready to drink cordial can be obtained. Dilute to taste and serve with lots of ice.