Blanch bones by boiling in water for 20-30 minutes.
Roast Bones for 30 minutes at 400 degrees.
Place bones, garlic, and apple cider vinegar in large stockpot. Add enough water to cover bone.
Bring to a boil. Cover, reduce to a simmer and cook for 24-48 hours.
Strain liquid into a shallow dish with ice to cool down quickly.
Store in the fridge for up to 7 days or freeze for long term storage.