500 g blueberries
250 g sugar
5-6 drops of caramel flavor
½ cinnamon stick
¼ Tonka bean, ground
Wash the blueberries, carefully removing the leaves, stems and other impurities. Transfer to a large saucepan. Pour over the sugar, which is half their weight.
Bring to the boil and when sugar melts, reduce the intensity of the fire. Continue cooking over low heat. Flavor to taste with cinnamon, tonka bean and preferred natural flavor (caramel flavor goes well with it).
Pour the blueberry jam in warm clean jars. As it is still hot, seal tightly with the lids (soaked in boiling water). Cool the jars upside down on their lids. The curved part of the lids must get sucked in when the jars cool completely.