1 kg (2.2 lbs) quince
300 gr (10.5 oz) sugar
Peel the quince and cut them into little bits. Combine in a pot with the sugar, and bring to a boil. Strain the jam through a food mill, return to the pot, and bring back to the boil. Cook until thickened. When the jam reaches 220ºF, ladle into sterilized jars and process 10 minutes in a water bath canner.
To make quince paste, spread the jam about a 1/2" thick layer in a baking dish or lined sheet pan and place into a 220ºF oven until set. Allow to cool, then cut into squares and roll them in cane sugar. Turn-of-the-century bicyclists used to use these as energy bars.