Among a certain group of food lovers, bone broth is enjoying its moment of hip, but as Food Guys Jon Jackson and Greg Patent point out, slow-cooked, mineral-rich meat stock never went out of style. 19th-century cookbooks always included a section in the back for food as medicine, with recipes for chicken soup and 'beef tea.'
Making bone broth is simple: simmer bones, water and vegetables for long enough to extract minerals, protein and collagen from the bones and cartilage. You'll enhance the flavor if you use bones that have already been roasted with onions and carrots at 400 degrees F for about an hour.
To prepare the broth, combine roasted chicken, beef, lamb or pork bones, cold water, onions, carrots, celery, peppercorns and some vinegar (to draw more minerals out of the bones) in a pot over low heat.
If your goal is a clear broth, increase the heat very, very slowly, and never allow the liquid to boil. This way, you'll also avoid the formation of scum.
Remember: "simmering" means a bubble or two breaking the surface now and then. 3-4 hours of simmering chicken or lamb bones should be adequate. But given their diameter, be prepared to simmer beef bones for 10-12 hours or longer.
If you're buying marrowbones or oxtail, ask the butcher to cut the bones in half, the better to expose their interior to the cooking water.
After cooking and straining, you can clarify the broth by filtering it through a fine sieve. Cool it as quickly and efficiently as possible, in wide, shallow containers. Don't refrigerate the broth until it has cooled down.
Jon describes successful bone broth as a sort of meat Jell-O: "It's the difference between a lump of fat and a clear, shimmering thing with delicious umami qualities."