When selecting the bones for broth, look for high-quality bones from grass-fed cattle or bison, and pastured poultry. Since you’ll be extracting the minerals and drinking them in concentrated form, you want to make sure that the animal was as healthy as possible.
You will need a 6-quart crockpot.
Place beef bones, carrots, celery, leek, onion, and garlic on a roasting pan or rimmed baking sheet and roast for 20 minutes.
Toss the contents of the pan and continue to roast until deeply browned, about 20 minutes more.
Fill a large (at least 6-quart) crockpot with 10-12 cups of water, turn on low.
Add celery, bay leaves, thyme, peppercorns, and vinegar.
Scrape the roasted bones and vegetables into the pot along with any juices.
Add more water if necessary to cover bones and vegetables.
Cover the pot and cook on low for 12-24 hours. The longer it cooks, the better.
Strain broth using a fine-mesh sieve and discard bones and vegetables. Let continue to cool until barely warm, then refrigerate in smaller containers overnight.
Broth can be stored for up to 5 days in the refrigerator and up to 6 months in the freezer.