In a medium saucepan, combine the fresh blueberries, granulated sugar, and water. Stir gently to mix the ingredients.

Place the saucepan over medium heat. As the mixture heats, the blueberries will begin to release their juices.

Bring the mixture to a gentle boil, then reduce the heat to low. Allow it to simmer for about 10-15 minutes, stirring occasionally. This helps to break down the blueberries and thicken the syrup.

After simmering, the blueberries should be soft and the mixture should have thickened slightly. If you prefer a smoother syrup, use a wooden spoon to mash some of the blueberries against the side of the pan.

Remove the saucepan from heat. Pour the mixture through a fine mesh strainer into a bowl or another saucepan to separate the solids from the syrup. Use the back of a spoon to press down on the solids to extract as much liquid as possible.

Stir in the fresh lemon juice and vanilla extract (if using) into the strained syrup. This adds brightness and depth to the flavor.

Allow the syrup to cool to room temperature. Once cooled, transfer it to a clean storage jar or bottle.

Store the blueberry syrup in the refrigerator for up to 2 weeks. Use it as a topping for pancakes, waffles, or desserts.