A proper bone stock does not contain fat. This may surprise those who would just as soon make stock from a rotisserie chicken carcass tossed into a pot of hot water. But stock is not that steaming, rejuvenating bowl of broth on a cold day. It is an ingredient rather than a finished product. Stock is not even salted.
Fat and salt can be added later, as they are in demi-glace, perhaps the most storied of sauces. Here, bare-bone stock is combined with its alter ego: the fat- and flour-saturated roux known as espagnole. But devoid of salt and fat, bone stock can only offer subtle complexity of flavor, viscous body and the glistening sheen of melted cartilage.
The bones of young animals are collagen-rich, making them best for stock. Collagen gives young bones their characteristic elasticity, and when heated breaks down into gelatin, which imparts a thick, non-fat creaminess.
Stock will add body and flavor to soups, sauces, risotto, mushrooms and most any other savory dish. And with that complexity of flavor comes many important nutrients. Bones are an organ, containing a rich array of minerals like calcium, magnesium and phosphorous, as well as biomolecules like chondroitin and glucosamine—which people pay big bucks for in the form of joint-healing supplements. There are also goodies in bones you may never have heard of, like hyaluronic acid, which has been used for years to treat osteoarthritic racehorses, and is now showing promise in human trials.
Save leftover dinner bones until you have enough to make a batch of stock, or gather bones from hunters, butchers and cooks. Buy them as soup bones, dog bones or T-bones. Good stock bones should be fresh, or frozen fresh, and clean of meat, fat and blood. Tendon and cartilage are welcome.
Stock made from mammal bones is often called "brown stock." Recipes for classic brown stock typically call for veal bones, but cow, deer, elk and lamb all work in the following recipe.
Long bones like femurs are best because they have the most marrow, but shoulders work well too. If you're processing game at home, use a bone saw to cut two-inch rounds; if you're buying the bones, have the butcher cut them down to size. Alternatively, roast the bones for an hour, smash them with a hammer and then roast for another hour or two and proceed.
However you get the bones down to size, they should be roasted two or three hours in a 350-degree oven, or until golden brown but not burnt. Let the bones cool, and strip any clinging meat or fat.
Some stock recipes skip this bone-roasting step, but you'll get a richer stock by roasting. The caramelization facilitates a complexity unattainable by simmering alone.
Put the roasted bones in a large, empty pot, and heat the roasting pan on the stovetop. Pour some wine or water into the hot roasting pan to deglaze the fond.
(Fond is French for the stuff stuck to the bottom of the pan; deglaze means to pour a liquid, usually water or wine, into a hot fond-laden dish to release its caramelized, gelatinous goodness.)
Pour the deglazed fond and accompanying bone juice drippings into the bone pot. Add a bay leaf, a teaspoon of peppercorns and enough water to cover everything. Cook slowly for 12 to 24 hours at a lazy bubble—the point at which a single bubble lets go from the bottom every three to four seconds. Even a simmer is too much heat. Add water as needed to keep everything covered, and skim any scum that gathers on the surface.
Cool to room temperature and put the pot in the fridge overnight. By morning, any residual fat will be floating on top and easy to skim.
Reheat to the lazy bubble stage. Meanwhile, chop the following (for up to eight pounds of bone): a pound of onion, and half a pound each of carrot and celery.
This mixture of aromatic vegetables is called mirepoix (pronounced "mere-pwah"), and named after a 19th century French aristocrat who employed a very good cook who famously used it. Parsnips are often subbed for carrots, or added alongside. The same interchangeability applies to celery and celery root, and to onions, shallots and leeks. Parsley is also used.
Simmer the stock two hours, and then strain the bones and mirepoix. Pour the remaining liquid, cooled, into jars or bags for freezing, skimming any remaining fat as the opportunity presents itself. If stored in the fridge, stock should be used within a week. Frozen, it can last a year.
In addition to making stock by the batch load, its power can be also be harnessed from scratch in a single meal, by cooking tough cuts of meat attached to big bones. Shank is the best cut for this, as in osso buco, which literally means "bone with a hole" in Italian, a reference to the hollow marrow bone at the center of the shank.
What I do with shank isn't osso buco per se, but it's beaucoup bueno enough for this unfrozen caveman and well worth a try if you have a mammal shank bone or two on your hands.
Put the bone under the broiler at 350, turning it often until the browned meat starts to shrink from the golden bone. After an hour or two, add a mix of water and wine to the pan, along with a bay leaf, two tablespoons of olive oil and some peppercorns, and cook covered, at 350, until the meat is tender, turning occasionally, adding more water/wine as necessary to keep the shank mostly submerged. When the meat is spoon-tender, add the mirepoix and cook until the veggies are done. Add salt to taste, and serve. Unlike stock, in which the mirepoix and bones are strained out, this dish features the veggies and their soaked-up bone juice alongside the shank meat.
Young bones may be best, but don't let old bones get in the way of a good stock. Whether made from veal shank or bull knuckle, fawn femur or buck shoulder blade, a good stock will hit where it counts, helping your bones feel healthy and warm this winter.