Soak beef bones in cold water for about 3 hours to remove blood.
Place the bones in a pot, pour in water, and bring to a boil over high heat.
Once boiling, remove the bones, rinse them thoroughly, and wash the pot.
Return the bones and fresh water to the pot and bring to a boil again.
Simmer over medium-low heat for 8–12 hours or longer.
Skim off any fat and strain the broth through a sieve.
Season with salt or other seasonings to taste.