Step 1: In a medium saucepan, combine the blueberries, granulated sugar, and water. Stir gently to ensure the sugar is somewhat distributed.
Step 2: Place the saucepan over medium heat. Bring the mixture to a gentle simmer, stirring occasionally. The blueberries will start to release their juices as they heat.
Step 3: Once simmering, reduce the heat to low. Continue to cook for 10-15 minutes, stirring frequently, until the blueberries have burst and the syrup has thickened slightly. For a smoother syrup, you can gently mash the blueberries with a spoon or potato masher.
Step 4: Remove the saucepan from the heat and stir in the fresh lemon juice. This brightens the flavor and helps enhance the color of your blueberry syrup.
Step 5: For a smooth syrup, carefully pour the mixture through a fine-mesh sieve into a clean bowl or jar. Press on the solids with the back of a spoon to extract all the liquid. Discard the pulp (or save for another use). If you prefer a chunky, rustic syrup, skip the straining step.
Step 6: Allow the blueberry syrup to cool completely to room temperature before transferring it to an airtight container. The syrup will thicken more as it cools. Store in the refrigerator for up to 2-3 weeks.