Scrub the quinces to remove any velvety fluff from the skin.
Place the whole quinces in a deep saucepan, enough to hold each other up in a wedged, upright position. Just one layer on the bottom of the pan. Add enough water to the pan so that the quinces are three quarters submerged in the water. (scroll through the images above to see).
Cover the pan and gently simmer the fruit for about 40 minutes until tender.
Remove from the heat and leave until cool enough to handle.
Reserving the liquid, take the quinces and remove as much peel as you can. Then pull the flesh from the core. Don't worry if you get a few pips, core and skin in with your fruit because you are going to sieve it.
Liquidize the flesh that you have retrieved and pass it through a mouli or nylon sieve to remove any core, pips and skin.
Add the reserved cooking liquid to the liquidised flesh and weigh it. For every 100g of quince puree add 60g of granulated sugar.
Return the weighed puree and sugar to a deep saucepan and slowly bring to a boil. (the bigger the saucepan the better, to stop the bubbling lava from getting you)
Keep stirring from time to time with a long handled wooden spoon, until the mixture starts to thicken and darkens to a deep red. As it thickens stir constantly, until the spoon drawn through parts the fruit into two sections. (see images above)
Spread the thick fruit into a bakewell paper lined or oiled tin to set. The end result looks best if the paste is 4 or 5 cm deep.
Leave to cool overnight then turn out and cut into portions. Wrap each portion in cellophane to store. Although it's not essential to refrigerate I usually keep mine in the fridge for months.