Begin by washing the blueberries thoroughly under cool running water to remove any dirt or residue.

In a medium saucepan over medium heat, combine sugar, water, and the cleaned blueberries. Stir gently as the sugar begins to dissolve.

Once the mixture comes to a gentle simmer, allow it to cook for about 15 minutes. During this time, the blueberries will soften, and the syrup will begin to thicken slightly.

Remove the pan from heat and stir in either lemon juice or lemon extract, depending on your preference. Lemon juice offers a more natural citrus touch, while extract provides a stronger flavor in smaller amounts.

Let the syrup cool to room temperature. Once cooled, use a fine mesh strainer to remove the solids, pressing the blueberries gently to extract all the flavorful liquid.

Transfer the strained syrup to a clean, airtight container and refrigerate. It will keep for up to three weeks.