Wash, peel, clean the quinces of seeds and cut them into cubes. Put the fruits in a deep tray and sprinkle with 3.5 lb (1.5 kg) of sugar.
Add 2 cups (500 ml) of water and put it on the stove. Once the water comes to a boil, began to stir with a slotted spoon.
Reduce the heat. Remove the foam that forms. Then add 2 tablespoons cognac to preserve the color of the jam. Once the syrup thickens, add the citric acid and the geranium leaves. Mix well and remove from the heat.
Distribute the jam into dry jars, put the lids on and turn upside down. Leave for 24 hours in a cool place.