For 4 people
Wash the blueberries previously raised in cold water, then weigh them to obtain the recommended weight.
Put the blueberries in the jam bowl and pour the sugar into it. Mix everything with a wooden spatula and leave to marinate for a few hours.
Once the maceration is finished, heat the mixture over high heat while regularly mixing with a spatula until boiling.
Keep the cooking for 7 minutes if your choice fell on a gelling sugar. Otherwise, count about fifteen to twenty minutes in the case of semolina or crystallized white sugar.
When the mixture becomes a syrupy, crush the blueberries using a skimmer until a homogeneous mixture is obtained.
Pour a few drops of jam on a plate and lean it slightly. The jam must be viscous and sink gently.
Sapp the jam and pour it into the pots. Place the pot upside down for 1 minute. Straighten the pot and let stand until the jam cools