Remove any meat still left on the turkey and discard anything you stuffed in the cavity. Place the turkey carcass and bones in a large stockpot with COLD water. I just fill the pot to about 2 inches below the rim. You can break the carcass up to fit the pot, if necessary.
Put the heat on high and bring to a boil. Immediately lower the heat to the gentlest simmer and skim any foam that surfaces.
Add the vegetables and apple cider vinegar and continue to simmer, partially covered for about 2-5 hours (or as long as you have.)
Strain the stock (use a fine mesh sieve to make it very clear) into a large bowl or individual containers and cool before refrigerating. Keeps in the refrigerator 3-4 days or frozen up to 3 months.