Place blueberries into a large pot or a salad spinner.

Fill colander with water and let the berries soak in cold water for about 5 minutes. This helps loosen debris and leaves, which will float to the surface.

Rinse the blueberries thoroughly until the water runs clean.

Place half of the blueberries into a suitably sized pot and add roughly ¼ cup of sugar.

Use a potato masher to mash the berries with the sugar.

Add the remaining blueberries and another ¼ cup of sugar.

Mash the berries and sugar until you have a homogeneous mixture.

Cover the pot and let it sit for at least 8 hours or overnight. This allows the sugar to draw out the juices from the blueberries, a key ingredient for making blueberry jelly.

After the resting period, there should be plenty of blueberry juices in the pot. Bring the blueberries and their juices to a boil over medium heat, stirring often to dissolve the sugar.

Once boiling, lower the heat to medium-low and cook for 15 minutes.

Turn off the heat and use a fine mesh strainer or jelly bag to strain the blueberry juices into a separate pot. This juice will be the base of your syrup. You can discard the blueberry pulp or use it to make a delicious summer drink by mixing it with hot water.

Mix ¼ cup of sugar with the pectin and set aside. This will help the jelly mixture set.

Add the remaining sugar to the strained blueberry syrup and bring it to a boil.

Once boiling, reduce the heat to medium and cook for 15 more minutes.

Add the sugar-pectin mixture to the cooking blueberry jelly liquid. Mix vigorously to ensure the sugar and pectin are well incorporated into the jelly mixture.

Cook for an additional 10 minutes. Perform a chilled plate test to check the jelly consistency. Cook for 5-10 minutes more if you prefer a denser jelly.

Pour the hot blueberry jelly into clean, sterilized canning jars.

Process the jars using your preferred canning method.