The quince is a very old fruit. It was cited around 600BC by the Greeks and Romans, and it is a component of middle eastern cuisine. The raw quince fruit is very fragrant, but the flesh is dry, astringent, and very hard. It is transformed with heat and becomes supple and edible. A little sugar doesn't hurt, either.
5 large quince is about 1kg gross and yields 6C quince and ginger.
6.75 large quince is about 800g net, and yields 5C quince, orange and cardamom.
1.25 large quince yields 2C quince jam.