It is important to use several sorts of bones: knuckle bones and feet impart large quantities of gelatin to the broth; marrow bones impart flavor and the particular nutrients of bone marrow, and meaty rib or neck bones add color and flavor.

Place the knuckle and marrow bones and optional calves foot in a very large pot with vinegar and cover with water. Let stand for one hour.

Meanwhile, place the meaty bones in a roasting pan and brown at 350 degrees in the oven.

When well browned (this can take as little as 20 minutes), add them to the pot along with the vegetables.

Pour the fat out of the roasting pan, and add to the stock pot.

Add enough cold filtered water to the pot to cover the bones by 2-3 inches, leaving at least one inch of room from the top of the pot, as the volume expands a bit during cooking.

Bring to a boil.

A large amount of scum will come to the top, and it is important to remove this with a spoon. After you have skimmed, reduce heat and add the thyme, bay leaves and crushed peppercorns.

Simmer stock for at least 12 and as long as 72 hours. (I prefer to let mine go for the full 72 hours.)

Just before finishing, add the parsley and simmer another 10 minutes.

Remove the bones and save them for another batch of stock. I usually reuse my bones at least once for smaller bones and up to 3 times for much larger bones in another batch. I will get some fresh meaty bones to mix up with the already used bones to ensure I get some more flavor and nutrients.

Strain the stock and cool in the fridge.

Your jars of stock will have a layer of congealed fat on top and you can leave that in or remove it and save it for cooking with.

Your stock should also be very thick and gelatinous when cooled.