Quinces are pretty inedible straight off the tree – like a cross between a pear and an apple but made out of concrete. Cook them though and they turn into a beautiful princess (‘quince’ means princess in Portuguese!*).
Recipe for jelly;
quarter about ten quinces (the weight doesn’t matter, we’ll measure the juice that comes out to work out the other stuff). Use a good board & knife, they’re super hard and will need some muscle. Leave everything on – skin, pips, fuzzy down on the outside.. Bung them in a pan, cover with water then add another 5cm of water. Bring to the boil and simmer for about 80 minutes until they’re soft and mushy. Use a hand blitzer or spud masher to turn it all into pulp. Then stick it through a muslin lined sleeve/jelly bag and leave to drip out. You should get out around a litre of juice (if you’re nowhere near that put it all back in the pan add more water and bring back to the boil and pass through a sieve again). (If you’re hardcore and wanna make membrillo as well put the pulp through a fine plate in a food mill, discarding the bits left behind – that recipe’s tomorrow!) Put the juice into a clean pan and add sugar – 90% of the volume of juice, so if you had a litre of juice then use 900ml of sugar. Bring to the boil again and simmer then add the juice of 1 lemon (roughly 1 lemon to each litre of quince juice). Keep it going until it hits 104C then skim any foamy crap off the top and pour into a clean jar. If you don’t have a thermometer put a spoonful onto a cold plate and stick in the fridge for a coupla minutes, give it a nudge with your finger and if it wrinkles up then it’s done. If you’ve bottled it and when it’s cooled decide it hasn’t set enough just empty it back into a pan and cook down a bit more.
Why does it turn red?
Something called anthocyanin in the quince which is bound up in the tannins and only released when cooked. Because it’s water soluble it turns the liquid red as it cooks.
* it so doesn’t