Reserved backbone, neck and wings from an 18-pound turkey, or 6 pounds turkey
6 quarts water
4 garlic cloves
2 celery ribs
1 carrot, peeled and thickly sliced
1 onion, halved
1/4 teaspoon peppercorns
2 parsley springs
2 thyme sprigs
1 bay leaf
Combine all of the ingredients in a large stock pot and bring to a boil. Reduce the heat to moderately low and simmer, skimming as necessary, until the stock is flavorful and reduced to 12 cups, about 3 hours. Strain the stock and skim off the fat.
The stock can be refrigerated for up to 3 days or frozen for up to 3 months.