To prepare the quince syrup, start rubbing the quinces with a cloth, then wash them.
Quarter and core them, then chop the quarters into pieces.
Place the chopped quinces in a pan with 100 g sugar, the lemon juice and lemon peel.
Pour on 1 l water and bring to the boil, then cover and simmer for approx. 45 minutes until soft, stirring occasionally.
Let cool and filter through a sieve lined with a cloth into a pan, squeezing the quinces thoroughly.
Stir in the remaining sugar, bring to the boil and boil vigorously for 5 minutes.
Fill the juice into prepared bottles (sterile).
Close tightly and let the quince juice cool.
The quince syrup will keep for at least 6 months if stored in a cool, dark place.