Follow these simple steps to create your own Copycat Starbucks Blackberry Sage Refresher:

1. Prepare Blackberries: In a medium bowl, mash the fresh blackberries with a fork until they are juicy and partially crushed.
2. Add Sugar: Stir in the granulated sugar, mixing well to ensure the sugar incorporates with the blackberries.
3. Include Lemon Juice: Add the fresh lemon juice to the blackberry mixture, stirring until everything is well combined.
4. Boil Water: In a small saucepan, bring 2 cups of water to a boil.
5. Add Sage Leaves: Once the water is boiling, remove it from heat and add the fresh sage leaves. Let steep for about 3-5 minutes.
6. Combine Mixtures: Strain the sage-infused water into the blackberry mixture, discarding the sage leaves.
7. Chill: Allow the mixture to cool in the refrigerator for a few minutes.
8. Serve Over Ice: Fill glasses with ice cubes, then pour the blackberry sage mixture over the ice.
9. Top with Sparkling Water: Finish by topping off with sparkling water for added effervescence.
10. Garnish: Optionally, garnish with a sprig of fresh sage or a few whole blackberries for a beautiful presentation.