How to Make It
Place the carcass and skin of a roasted 12- to 14-lb. turkey in a very large stockpot. Add 2 qt. reduced-sodium chicken broth; 16 cups water; 2 chopped celery stalks; 2 chopped carrots; 1 yellow onion, quartered; and 1 Tbsp. kosher salt. Bring to a boil over high; reduce heat, and simmer until carcass falls apart and stock tastes very rich, 2 to 3 hours. Remove and discard large bones; pour liquid through a fine wire-mesh strainer, and discard solids. Cool completely, about 2 hours; cover and chill until ready to use. Skim and discard solidified fat before using. Refrigerate stock up to 1 week, or freeze up to 6 months.