Prepare quinces the day before and cut them into large pieces. Sprinkle with lemon juice immediately. Boil quinces and 2 l water in a large pot. Simmer covered for about 1 hour. Hang one copy in each of two pots and line with moistened gauze cloths.
Spread the quinces together with the liquid over the strainers and leave to drain for at least 12 hours (overnight).
The next day, press out the gauze cloths with the quinces. Measure out 1800 ml quince juice. From this 1⁄2 l juice take off and boil up. Take off the stove. Leave tea bags in it for about 10 minutes and remove.
Mix with the remaining quince juice and jam sugar in a large pot. Bring to the boil at high heat and stir fizzy for at least 4 minutes.
Pour jelly immediately into prepared glasses. Seal tightly. Place on the lid for about 5 minutes. Turn over and let cool off. Tastes great with raisin rolls.