Recipe Instructions:
2 pounds (1 kilogram) organic, unwaxed lemons
10 cups (4.4 pounds or 2 kilograms) sugar
Wash your lemons well and cut off the little buttons on the tops where the stems were, then place in a large jamming pot (a heavy based one with tall sides is ideal) with about 2-2 1/2 litres (8-10 cups) water. Simmer these whole lemons gently until the skins become incredibly soft and a fork slips through easily—about 2 hours if large, 1 hour if they are small and the skins fine.
Remove the lemons from the pot, saving the water left in the pan and topping up, if necessary, to have about 1 1/2 litres (5 cups) of liquid.
If using a food mill, it is sufficient to cut the lemons in quarters and pass through a food mill set over a bowl to collect the pulp. The seeds and some hard membranes will be separated from the pulp and can be discarded. If you don't have a food mill, halve the lemons and scoop everything out with a spoon. Place the insides (pith, seeds, pulp and all) in a colander over a bowl to drain and set aside the skins for the moment. Strain out the seeds like you would with an orange squeezer/hand juicer (actually you could use one of these too to remove the seeds) and discard them. Blend the pulp/juice along with the skins you set aside with a food processor or blender.
Return the blended pulp and skins to the pan with the lemon water, along with the sugar (if you are using sweeter lemons and want to use less sugar, taste as you go).
Place a saucer in the freezer to test the marmalade later.
Bring the marmalade to a boil and boil rapidly for about 20 minutes for a soft set. The liquid will first look very opaque and a little frothy, then as it cooks, it will turn transparent golden and shiny. To test if the jam has set, place a blob of hot marmalade on it, pop it back in the freezer for 30 seconds and then take a look at it. Poke it or turn the plate a little, if you can see the surface crinkle, it's done. If you prefer a firmer set jam, leave it a little longer and test the jam on the cold saucer.
Ladle the hot jam into the jars one by one (be careful of fingers, hot jam burns!). Seal the lids tightly (a dishcloth helps protect your hands) and set aside. Place the jars in a large boil and fill with water to their necks. Bring to the boil and simmer for 10 minutes. Let the jars cool. As the jam cools, the seals should tighten and contract. Store somewhere cool and dry; once opened, store in the fridge.