For the blueberry jam, wash the blueberries and sort them well. Then put them in a saucepan and cover with the preserving sugar.
Cover the saucepan and let it stand for about 3 hours, so that juice is formed.
Then stir well, add lemon juice and cinnamon stick and cook the mixture according to the instructions on the jelling sugar packet.
Make a jelly test and remove the cinnamon stick. Pour the blueberry jam into clean jars and seal well.