Lemons (9 1/2 cups)
into a large heavy-bottomed pot and cover with
Water (8 1/3 cups)
. Close the lid of the pot and set the lemons over high heat to cook for 20 minutes or until soft.
Use tongs to remove the lemons from the water, reserving the water in the pot. Let the lemons cool.
Slice away the lemon stalk and scoop out the pith and seeds. Reserve the pith and seeds. Thinly slice the lemon peel and add it back into the cooking water.
Spoon about half of the reserved pith and seeds into a square of muslin and tie tightly with string. This will cook in with the lemon and add pectin to naturally set the marmalade.
Set the pot with the cooking liquid and peel over high heat and pour in the
Granulated Sugar (10 cups)
. Stir the mixture until the sugar has dissolved and add in the muslin bag.
Leave the mixture to gently boil over low heat for 30-40 minutes or until set. To check the setting level of the marmalade, spoon a drop of the liquid onto a chilled plate. Push the drop with your finger and if it crinkles, the marmalade is ready. If not, continue to boil the mixture.
Once set, remove and discard the muslin bag and leave the marmalade to cool slightly.
Spoon the marmalade into sterilized glass jars and refrigerate upon opening.