With any recipe that calls for stock, you're faced with a choice of either using store-bought stock or making your own. Obviously, making your own is more time-consuming, but a good-quality homemade stock can rival or even surpass a store-bought one. If you're thinking about making your own stock, here are a few tips.
Bones: Cartilage Provides Gelatin
With the exception of vegetable stock, all stocks are made by simmering bones in water with aromatic vegetables, herbs, and spices.
The key ingredient in bones is the cartilage, which is a connective tissue found at the joints and in the places where muscles are attached. Cartilage is high in collagen, which—when simmered—breaks down and forms gelatin. This gelatin is what gives stock its body.
Therefore, the best bones for making stock are the so-called knucklebones, such as shoulder, elbow, and knee joints of beef and veal—as opposed to so-called marrow bones, which are cross-sections of large bones such as the thigh but with no cartilage attached. Veal bones are high in cartilage since they come from younger animals, making them especially desirable.
With chicken and turkey stock, you're generally simmering the whole carcass, so you don't have to worry about which bones to use.
What's the Difference Between Brown and White Stocks?
Different sauces require different stocks. Demi-glace and its family of sauces are made from brown stock. Veloute and its various derivative sauces, including the allemande, white wine, and supreme sauces, are made from white stock.
Brown stock is made from beef or veal bones and the brown color of the stock is produced by roasting the bones. Additional color is obtained by adding some sort of tomato product, such as tomato paste, during the roasting process. After roasting, the bones are transferred to a stockpot, covered with cold water, and simmered.
White stock is made from veal bones, which are not roasted but instead blanched (cooked briefly in boiling water), then transferred to a stockpot, covered with cold water, and simmered. Chicken and turkey stock are also variations on white stock.
The goal of simmering is to extract the collagen from the connective tissue. This takes longer with beef and veal bones then it does with chicken or turkey bones, which is why chicken stock takes a relatively short time to make.
Fish stock, which is made from fish bones, requires the least amount of simmering.
Tips for Making Stock
Start with cold water: Some of the proteins in collagen are soluble in cold water and some in hot. For the richest stock, it's important to start the bones in cold water and bring them to a simmer.
Don't stir: Although it might be tempting to give the pot of stock a whirl with your spoon as it simmers, resist this temptation. Agitating the stock will make it turn out cloudy. Do, however, skim off any scum that rises to the surface.
Don't over simmer: As mentioned, the simmering time for a stock is related to how long it takes to extract the gelatin from the bones. Continuing to cook beyond this point will not help your stock, and can actually hurt it as the aromatics such as the carrots and celery can start to turn bitter.
Don't season: In general, it's a bad idea to season stock with salt. Why? In almost every case, that stock is going to be used to prepare some other recipe, whether it's a sauce, a soup, or a stew. And since whatever that dish is, your stock will be reduced to some extent, possibly a great extent, salt in the stock will become concentrated. So season the final product, not the stock.
Is Vegetable Stock Really Stock?
Even though it's called stock, any product labeled vegetable stock is really merely vegetable broth. That's because vegetables don't have bones and they contain no cartilage, so there's no way to make stock from them.
Even so, the liquid you produce from simmering vegetables can be extremely flavorful. It's also easy and quick to make and is far preferable to water as a cooking medium or a base for soups, stews, and sauces—even if you aren't vegetarian.
A combo of onions, carrots, and celery, simmered for 30 minutes along with a few cloves of garlic, a bay leaf or two, several sprigs of thyme and parsley, and some whole black peppercorns, will produce a wonderfully flavorful vegetable cooking liquid—whatever you decide to call it.