Step 1 - Place the 2 litres of water in a large pan and add the squeezed juice from the oranges using a sieve to reserve any pips and pith.
Step 2 - Cut the skins in half and use a teaspoon to scrape away any pith. Place all of the pips and pith into a square of muslin and tie it tight. The muslin should be added to the liquid in the pan.
Step 3 - Slice the peel into strips depending on what cut of marmalade you want. Add the peel to the pan, bring to the boil and then simmer for 1.5 - 2 hours.
Step 4 - Take the muslin out of the liquid and when cool enough to handle squeeze as much juice as possible back into the pan.
Step 5 - Add the sugar and stir until completely dissolved. Boil the mix for 15 minutes and check to see whether marmalade is at setting point. You can check by placing a teaspoon of the mix on a cold plate, leaving it for a few seconds and then pushing your finger through the mix. If the marmalade wrinkles it has reached setting point, if not, boil for a further five minutes and test again.
Step 6 - Allow the marmalade to cool for 10 minutes and then spoon into sterilised jars that are still hot from the oven.