These are really pseudo quinces, genus Chaenomeles, produced on thorny shrubs; the fruits are rock hard, but some people do succeed in making a clear jelly, although one must ask whether it is worth the effort.
The true quince is Cydonia oblonga, a tree fruit but also rock hard. Usually pear-shaped, and has surface soft fuzz; kept uncovered in a room it emits agreeable gentle aroma.
Produces a ‘gritty’ textured paste rather than jelly, available in small tubs at Waitrose cheese counters.
Thank you very much, Jeff, for your comment, very interesting.
I have in the past successfully made jelly from the true quinces together with apples. But the tree did not have any fruit this year hence the plan with the Japanese quinces, but in light of your comment perhaps I’ll give it a miss.
Yes, you can make great ‘lemonade’ out of them. Cut them into gravel size pieces, then leave in a large cup of water. After you drink the water, do it again. Then cut them into half as big of pieces, and soak for 15 minutes. More lemonade. I like it. See what you think. You get all the flavour. After about the third time, the flesh is bland and fibrous, I compost it.
My Japanese quince are quite small,but at least this year there are enough fruits to bother and might make 3 pots for gifts. I presume I can add apples and pears to enhance the flavour, does anyone know if any spices could ‘pep’ things up a bit?