The Best Classic New England Creamy Clam Chowder

Name: The Best Classic New England Creamy Clam Chowder
Ingredients: 6 ounces bacon (diced (use salt pork for more traditional flavor)); 1 large onion (finely chopped); 6 celery stalks (finely chopped); 2 cloves garlic (minced); ⅓ cup all purpose flour; 4 cups clam juice (from 4 8-oz bottles or reserved from steaming clams (instructions below)); 2 cups water; 1 large sprig thyme; 1 bay leaf; 2 pounds red skin potatoes (diced); freshly cracked black pepper ( to taste); 1 ½ cups clams, finely chopped (from 3 6.5 ounce cans or about 6 lbs of fresh clams in-shell); 2 cups heavy cream; fresh chives or parsley (minced, optional ); kosher salt (only as needed); crusty bread (optional, for serving)