Orange Marmalade: A Proper Preserve with Seville Oranges

Instructions:

1. Clean and Core: Scrub the oranges and lemons. Cut the fruit in half. Scoop out all the pips, pith, and membrane using a spoon, reserving all these scraps.
2. Prepare Pectin Bag: Place the reserved pips, pith, and membrane into the center of a square of muslin/cheesecloth. Tie it tightly with string to form a bundle (the 'pectin powerhouse').
3. Slice the Peel: Slice the orange and lemon peels very thinly. Place the sliced peel, the pectin bag, and the cold water into the preserving pan.
4. Soak: Bring the mixture to a gentle simmer, then turn off the heat. Cover and let the mixture soak for 12–24 hours. (This is essential for pectin release).
5. Soften the Peels: Bring the mixture back to a boil. Reduce heat and simmer gently for 1.5 to 2 hours, or until the orange peels are completely translucent and easily crushed between two fingers.
6. Remove Pectin: Once the peels are soft, lift the pectin bag out of the liquid. Press it firmly against the side of the pan to squeeze out all the pectin-rich liquid. Discard the empty bag.
7. Heat the Sugar: While the peels are simmering, warm the granulated sugar gently in a low oven (about 120°C / 250°F) for 15 minutes. This prevents the sugar from cooling the mixture down later.
8. Dissolve the Sugar: Add the warmed sugar to the pan. Stir gently over low heat until every single sugar crystal is completely dissolved. Look for perfect clarity in the liquid.
9. Rapid Boil: Increase the heat to maximum and bring the mixture to a rolling boil (one that cannot be stirred down). Cook rapidly, stirring occasionally, until the temperature reaches 105°C (221°F).
10. Test for Set: To confirm the set, drop a teaspoon of the hot marmalade onto a saucer chilled in the freezer. Place the saucer back in the fridge for 30 seconds. Push the surface with your finger—if it wrinkles, it’s set. If not, boil for another 5 minutes and test again.
11. Rest and Skim: Turn off the heat and let the marmalade stand for 15 minutes to allow the peel to distribute evenly. Use a slotted spoon or ladle to skim any foam or scum from the surface.
12. Fill Jars: Carefully and safely ladle the hot marmalade into hot, sterilised jars, filling right up to the rim.
13. Seal and Cool: Immediately cover with sterilised lids or waxed discs, and seal tightly. Allow the jars to cool completely before labeling and storing in a cool, dark place.