Place parsley in the bottom of a large soup pot or Dutch oven.
Place bones in the pot.
Add apple cider vinegar and vegetables.
Add enough water to cover the ingredients by an inch.
Bring just to a boil then reduce heat to low. Skim off any foam that rises to the top during the first hour of cooking.
Cover and simmer on the stove top lowest setting for 24 hours. You may need to add a little water during the cooking process if it water level goes below the top of the ingredients.
Strain into a large pot or metal mixing bowl. Discard cooked bones and vegetables.
Fill the sink with ice and cold water. Place the broth in the ice bath and cool the broth to about 50°F, about 15 minutes. Stir often while the broth is cooling.
Pour the broth into an airtight container and place it in the refrigerator overnight.