I scrumped a few windfall quinces at Brogdale the other day! (wouldn't that be a great opening line for a novel?) anyway, came home decided to make quince jelly.
What a terriffic success! HOORAY! Quinces have a high pectin content, but a low acid content. I blitzed them up in a food processor into chunks, and made jelly.
2lbs quinces - chopped roughly
3 pints water
juice of 3 lemons
Boil the quinces in the water with the added lemon juice (or citric acid) slowly for about an hour. Drain this through a muslin and allow the juice to drip out for about an hour. Do not squeeze the muslin, you do not want it to go cloudy. Put the quince pieces back in the saucepan, add another pint of water and boil for another 20 minutes. Drip through the muslin as before.
For each pint of quince juice you produce, add 1lb of sugar. Return the juice and sugar to a clean pan and boil rapidly for 10 minutes. After this, either use a thermometer and get the temperature up to the jam temperature of over 220F. Every 10 minutes or so, take a spoonfull out of the saucepan on to a cold plate. Put the plate in the freezer for 10 minutes to get an idea if the jelly is set. When it is - b0ttle it!
Mine was fantastic - it turns a dark peach colour on cooking. Tastes divine!