Preserved Lemon Marmalade

Boil the lemon shells in the soaking water until they are so tender, they can be pierced with a straw -- about 45 minutes. Drain the shells and cut them into very thin strips, about 1 inch (2 1/2 cm) long. Make a syrup with the sugar and water and boil for about 10 minutes. Add the strips of lemon and boil until clear, about 15 minutes. Remove and reserve the lemon strips, and add as much of the lemon juice and grated zest as liked. When boiled thick, about 20 minutes, put in the lemon strips and boil for a further 10 minutes. Put into glass jars, cover and process. Makes about 5 pints (2 1/2 liters). Done.