Polish Dill Pickle Soup (Zupa Ogórkowa)

Name: Polish Dill Pickle Soup (Zupa Ogórkowa)
Prep time: 20 min
Cook time: 28 min
Total time: 48 min
Cuisine: European
Ingredients: 2 large carrots; 2 large celery stalks; 1 medium yellow onion; 1 large leek; 4 to 6 whole dill pickles (made with salt and water brine, not vinegar brine); 1 pound Yukon gold potatoes (4 to 6 medium); 4 cloves garlic; 3 tablespoons unsalted butter; 1 (48-ounce) carton low-sodium chicken or vegetable broth (6 cups); 1 1/4 cups dill pickle brine, divided; 2 fresh or dried bay leaves; 1/2 teaspoon freshly ground black pepper, plus more as needed; 1 medium bunch fresh dill; 1/2 cup sour cream, plus more for serving; 2 teaspoons distilled white or white wine vinegar; Kosher salt; Rye bread, for serving (optional)