Orange Marmalade
From Hugh Platt Delight for Ladies. Original Translation from: Wilson, C. Anne. (ed) Banquetting Stuff. Edinburgh University Press. 1990.

I have misplaced my original on this, someday I will find it!
5
 Oranges (not Naval)
5
 Apples
150 ml
 water
A large amount of Sugar
Pectin
Wash the Oranges very well in hot water. Commercial orange growers wax their oranges for protection and to make them look shiny & lovely, if you leave the wax on the oranges it will ruin your marmalade. Peel, core and seed apples, then place in large stainless pot. Place a large strainer over the pot and quarter the oranges over the strainer. Remove the seeds and then squeeze into pot. Place all of the orange, except the seeds in with the apples. Add 150 ml of water to the pot and then bring it all to a gentle simmer. Cover and simmer for 1 hour (or until the apples are squishy and the orange peel is very soft), stirring to prevent sticking.
Pick out the orange peels and remove the pulp from the peel. Pick out the apples and leave the juice in the pot. Place the apple and orange pulp into a blender and blend until smooth. Pour blended mixture through a strainer into a bowl, then pour juice out of pot into bowl, stir well. Weigh the pulp mixture and return it to the cooking pot. Add an equal weight of sugar and stir over low heat. Stir until all of the sugar has been dissolved (if you run your spoon along the bottom or sides of the pot and feel graininess - keep stirring).
Theoretically the marmalade will set up into a very stiff paste that can be turned out onto a surface and then formed into a block. Our apples did not have enough pectin to set up, so we added Sure-JellŽ. We used ˝ a packet of Sure-JellŽ per batch, stir it in until dissolved and then bring the marmalade to a vigorous boil. Boil for exactly one minute and then take off of heat. Pour marmalade into greased pans to create freestanding blocks. For good, non-period, storage this can also be poured into canning jars.