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

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

Bring the mixture to a gentle boil, then reduce the heat to low. Allow it to simmer for about 15-20 minutes, stirring occasionally. This will help the blueberries break down and thicken the syrup.

After 20 minutes, the mixture should be slightly thickened. Remove the saucepan from heat.

Using a fine mesh strainer, strain the mixture into a bowl or another saucepan. Press down on the blueberries with the back of a spoon to extract as much liquid as possible.

Discard the solids left in the strainer.

Return the strained syrup to the saucepan. Stir in the fresh lemon juice and vanilla extract (if using). Heat over low heat for another 2-3 minutes to combine the flavors.

Remove from heat and let the syrup cool slightly before transferring it to a storage jar.

Once cooled, store the blueberry syrup in an airtight jar in the refrigerator. It will keep for up to 2 weeks.

Serve the syrup warm or cold over pancakes, waffles, ice cream, or yogurt.