Roast the bones at 400°F for about an hour until the bones are well-browned and fragrant. Roasting the bones ensures a good flavor in the resulting beef stock. Failure to do so may lend a sour or off-taste to the end product.
Once the bones are browned, drain off any fat.
Add the bones to a big pot along with the vegetables.
Add water to cover and bring to a boil. Once you’ve brought the water to a boil, add the vinegar and bay leaves.
Turn down the heat and continue to simmer for 12 to 24 hours.
Throughout the cooking process, skim off any foam and add water as needed.
When the stock is finished simmering, filter through a fine mesh sieve. The stock should set just like gelatin, and the fat should rise to the top.