In a small bowl, whisk 1/4 cup of blueberry juice into the cornstarch. Whisk until completely blended and lump-free.

Add blueberries, 3/4 cup blueberry juice, and sugar to a medium saucepan. Stir to combine. Cook over a medium-high heat until it reaches a boil.

Then lower flame, stir in the cornstarch mixture and simmer over a medium to medium-low flame for 7 minutes or until sauce thickens.

Carefully use either a blender or an immersion blender to grind up the blueberries.

If the syrup is too thick, you can add more blueberry juice 1 tablespoon at a time until you reach the desired consistency.

If your family does not like the chopped up bits in the syrup, you can pour it through a sieve before serving.