Wash and dry the fruit thoroughly. Cut off the ends and discard.
There are many ways to cut up the fruit and peel.1. Using a moderately coarse grater, grate off the peel and white pulp. Cut the flesh into thin slices, removing the seeds.2. Squeeze the juice out and cut the half skins into quarters and put them through the blender until fairly fine. 3. Cut the unpeeled fruit into quarters and then slice it thinly. The slices should be around 1mm or slightly less than 1/8 inch thick.Use only unblemished skin. If less rind and more jelly is preferred, cut the skins off and use only half of them.
Combine the peel and flesh and measure in cups how much there is.
Place the peel and flesh into a large saucepan and add 3 cups of water for each cup of peel and flesh.
Bring to the boiling, then put a lid on the saucepand and boil for 15-20 minutes until the peel is well cooked.
Remove from heat, cool slighlty and then measure the pulp in cups.
Return to the saucepan and bring to the boil.
Add 1 cup of warmed sugar for each cup of the cooked pulp that you measured (two steps above).
Boiling for 20 minutes, stirring occasionally with a wooden spoon. Remove any white residue that gathers. Depending on the amount of pectin in your fruit, you may need to cook for a bit longer than 20 minutes.
To test when done, place a tsp amount onto a chilled saucer (on that has been sitting in the freezer for a few minutes). Let the marmalade cool and the gently push it. If it wrinkles and seems thick, it is ready.
Take off the heat and stir to distribute the fruit and peel.
Ladle the marmalade into the warm jars.
Use a damp cloth to wipe spills around the rim of the jars. Seal with the lids.
Store the jars in the fridge for up to 4 weeks. You could also transfer the cold jam to a freezer safe container and freeze for up to 3 months.
If putting up for storage, use a hot water or steam canner to properly seal lids, according to canning instructions.