Homemade bone broth is one of the most powerful superfoods on the planet. It’s made by simmering the bones of a (preferably pasture-raised) animal for 10 – 24 hours in a slow-cooker, or 24 – 48 hours for beef bones. This low, slow cooking draws out the collagen, marrow, and other healing elements from the bones, including amino acids, minerals, glycine, and gelatin—which helps heal the gut and reduce inflammation. 

Ingredients
1kg (or more) of bones from a healthy source
2 chicken feet for extra gelatin (optional)
1 onion
2 carrots
2 stalks of celery
2 tablespoons Apple Cider Vinegar
Optional: 1 bunch of parsley, 1 tablespoon or more of sea salt, 1 teaspoon peppercorns, additional herbs or spices to taste. I also add 2 cloves of garlic for the last 30 minutes of cooking.
You'll also need a large stock pot to cook the broth in and a strainer to remove the pieces when it is done.

Instructions:
If you are using raw bones, roast them in the oven first. I place them in a roasting pan and roast for 30 minutes at 180.
Pplace the bones in a large stock pot (I use a 5 gallon pot). Pour (filtered) water over the bones and add the vinegar. Let sit for 20-30 minutes in the cool water. 
Rough chop and add the vegetables (except the parsley and garlic, if using) to the pot. Add any salt, pepper, spices, or herbs, if using.
Now, bring the broth to a boil. Once it has reached a vigorous boil, reduce to a simmer and simmer until done.
During the first few hours of simmering, you'll need to remove the impurities that float to the surface. A frothy/foamy layer will form and it can be easily scooped off with a big spoon. Throw this part away. I typically check it every 20 minutes for the first 2 hours to remove this. Grass-fed and healthy animals will produce much less of this than conventional animals.
During the last 30 minutes, add the garlic and parsley, if using.
Remove from heat and let cool slightly. Strain using a fine metal strainer to remove all the bits of bone and vegetable. When cool enough, store in the fridge for up to 5 days, or freeze for later use.