Mary Berry’s Seville Orange Marmalade is a traditional British preserve made by slowly cooking Seville oranges, sugar, and water until thick and glossy. The combination of orange zest, juice, and natural pectin from the peel ensures a rich, flavorful, and slightly tangy marmalade with a beautiful golden hue.
Wash the Seville oranges thoroughly to remove any wax. Cut them in half and squeeze out the juice, setting it aside. Remove any seeds and place them in a muslin bag (they contain pectin, which helps the marmalade set).
Using a sharp knife, finely slice the orange peel into thin strips. The thinner the slices, the smoother the texture of the marmalade.
Place the sliced peels, muslin bag with the seeds, and 2 liters of water into a large pan. Bring to a boil, then reduce the heat and simmer for 2 hours, or until the peel is soft.
Remove the muslin bag, squeezing out any juice before discarding. Stir in the granulated sugar and lemon juice, ensuring the sugar is fully dissolved.
Increase the heat and bring the mixture to a rolling boil for 15-20 minutes. To check if the marmalade is set, use the wrinkle test: spoon a little onto a cold plate, let it sit for 1 minute, then push it with your finger—if it wrinkles, it’s ready.
Turn off the heat and let the marmalade sit for 5 minutes before transferring it into sterilized jars. Seal tightly and allow to cool completely.