Blackberry Shrub

Name: Blackberry Shrub
Prep time: 5 min
Cook time: 15 min
Total time: 20 min
Cuisine: American
Ingredients: 8 ounces water; 12 ounces granulated sugar; .35 ounces fresh ginger (peeled and finely grated | optional); 12 ounces fresh blackberries; 12 ounces apple cider vinegar (or another mild vinegar like white wine vinegar); Ice cubes; 1 1/2 ounces homemade blackberry shrub (plus more as needed); 8 ounces seltzer, club soda, or soda water (preferably a citrus seltzer*)