Pat dry the quince with a piece of cloth, remove the flowers and peduncle, and cut the fruit into eighths. Boil lemon juice with 1¼ liters (approximately 6¼ cups) water in a pot, add the quince pieces and let simmer covered for 40 minutes.
Let the quince cool, drain and squeeze through a cloth. Collect the squeezed out quince juice. Measure 1 liter (approximately 5 cups) of quince juice, mix with jam sugar and boil for 4 minutes.
Skim off the foam repeatedly. Pour the quince jam into hot rinsed jars and seal well.
Tip: To preserve the jam for longer, you will need to process the jars according to manufacturer's instructions, or visit