I think this might be my favourite preserve of all. I love the fragrant quinces, the slightly bitter marmalade bite and that jewel colour … so pretty. Also, because quinces are so high in natural pectin, it sets beautifully.
Peel and core 600 g (1 lb 5 oz) of the quinces (about 2 quinces) and cut them into matchsticks, making them as thin as you can (these will replicate the citrus rind that traditionally floats around in marmalade).
Put the matchsticks in a large preserving pan or saucepan, add half the sugar and about 2 cups (500 ml) water – enough that everything is covered and the water comes about 4 cm (1½ inches) up the side of the pan.
Bring to the boil over high heat, then reduce the heat to low and slowly simmer for 1 hour.
Check every now and then to make sure the mixture isn’t sticking or burning and add a little more water if needed.
The mixture should be ruby red, jammy and gorgeous.
Set it aside to cool for a few hours or overnight.
Cut the remaining quinces into rough chunks, leaving the skin on, and place in a large saucepan with enough water to cover them by 2 cm (3/4 inch).
Bring to the boil over high heat, then reduce the heat and simmer for 2 hours or until the quinces and liquid have taken on that gorgeous ruby glow.
Add more water during cooking if needed to keep everything well submerged.
Rest a large sieve lined with muslin or a clean Chux cloth over a bowl.
Carefully pour the quinces into the sieve, cover with a tea towel and leave to drip and cool for a few hours or overnight.
You should end up with about 2 cups (500 ml) quince ‘juice’.
Pour the quince juice into a large preserving pan or saucepan and add the quince matchsticks, the remaining sugar and lemon juice.
Scrape the vanilla seeds into the pan, add the scraped pod and gently stir to combine.
Bring to the boil over high heat and cook for about 20 minutes, stirring often so it doesn’t catch and burn on the pan.
The marmalade is ready when it reaches reaches 118°C (244°F) on a sugar thermometer or passes the ‘set test’ (see here).
Transfer the marmalade into sterilised jars, seal and store in a cool, dark place for up to 6 months.