Clean the blueberries (if using fresh) in a bath of salt water or vinegar. Rinse well.

In a small saucepan, combine sugar, water, and berries. Heat over medium-high heat until simmering, stirring occasionally. Once softened, gently smash the softened berries with the back of a spoon or masher. Simmer for 5-7 minutes until the berries are disintegrated and the syrup is bright purple.

Remove from heat and strain out the berries and seeds through a fine-mesh sieve. Use a spoon to stir the mixture to release the syrup as needed, being careful to not let any of the fruit bits into the syrup, and discard them.

Optional: stir in a squeeze of fresh lemon juice to bring out the berry flavor if it's tasting flat; it's not about adding lemon flavor but rather enhancing the blueberry notes.

Let cool as needed and use immediately or store in an airtight container in the fridge for up to 2 weeks.