For the quince bread, rub each quince with a cloth and remove the white fuzz. Cut the fruit into quarters.
Simmer the quince pieces in a pot with 500 ml of water. Keep stirring and add a little water if necessary so that nothing burns.
When the quinces have broken down into puree, continue to cook for about 10 minutes while stirring. Then put the puree through a whisk and weigh it out. Bring the same amount of sugar as the puree to the boil.
Spread the puree on a baking sheet and dry in the oven at about 50 degrees until the mass is solid. This takes up to 20 hours. Then let it cool down.
Cut the quince bread into lozenges and roll in sugar.