Peeling the oranges means that you remove the peel and the thin white membrane (pith) that protects the citrus fruit segments. With a knife, simply cut off both ends of the orange. Place the fruit on one of its flat bases, to remove the peel of citrus fruit flesh, slide the blade of a knife from top to bottom, then remove any excess pith. This technique is called "blanching" the skin, an important step to reduce the bitterness of most citrus. Plate test - Place a small plate in the freezer for 5 minutes. To check the marmalade is at setting point place a spoonful on the plate and put it back in the freezer for a minute. Id=f the marmalade doesn't run you are good to go - if it does confute cooking and check every few minutes.