I had a notion to make some marmalade, so I looked around t’internets and found, then adapted someone else’s recipe. Here’s what I made:
1.3kg oranges (this turned out to be 5 large navel oranges)
1.3kg sugar
1.25l water
Juice of 1 lemon
I sliced the oranges very thinly, then put them in a pot with the water and the lemon juice to soak for 24 hours. This, apparently, allows the pectin to develop. I then boiled it up (with a lid on the pot) for 40 minutes, added the sugar, and cooked it at a rolling boil, uncovered, for a further 40 minutes.
Then I started testing the set every 10 minutes, by putting a small amount on a refrigerated plate and sticking it back in the fridge for two minutes. At the 4th go (after about another 30 minutes) I got the classic wrinkles after a couple of minutes in the fridge, and stopped cooking. I let it stand and cool a bit for a further 30 minutes before ladling it into jars.
These quantities made 5 jars of marmalade, which was handy, as that's how many empty jars I had.
This morning I tried it on my toast, and it worked! It had formed a proper jelly, and tasted nice and orangey, and wasn’t too sweet. This has been much more successful than my previous marmalading attempts which have either failed to set properly, or ended up by being a gloopy, sticky something that bore no real resemblance to real marmalade – possibly due to my being suckered in to using preserving sugar when I should have stuck to the ordinary granulated. I think the pre-soaking helped as well, so I’ll continue to use this technique.