The other day we walked around on the Saturday market in Dieppe and there was a stall with great-looking lemons. They were from Menton, which is at the Mediterranean while Dieppe lies at the English Channel. Nevertheless, Menton lemons are known for their quality and for being non-treated (that means they have not been sprayed with chemicals to make them look nice and resist insects) and therefore you can use their skin as zest.
We bought a kilo and took it home. They looked nice in a plate but then the question arose what to do with them. Non-treated also means perishable. One went on the sole I made that Sunday, the rest went into a jam.
Basically, I had six lemons left. Of three I zested the skin and then blanched the zests for 15 minutes. The other three I peeled “naked” (removing the whites and keeping the flesh) and then cut off the fruit in parts while removing the tiny inner skins. I pressed the lemons I had zested. Then I weighed the lemon pulp, zest, water and juice. It was some 750 grammes.
I measured 750 grammes of special sugar for jams (with added pectins that helps to set the jam).
I put the lemon mass in a pan and added the sugar and cooked for 20 minutes while stirring regularly. Then I poured it in clean pots, closed the lids and put them upside down to cool for 24 hours. This way you prevent air from entering the pots through the lids, making the jam more resistant to germs. The following day I turned the pots back. There was some air trapped beneath and the jam slowly sunk to the bottom.