Stock, generic recipe (with sous vide pictures)
Myself, I enjoy the day long process of tending a near boiling pot, of skimming, of straining and adding then straining again; but the Modernists have popularized two other methods for producing stock faster with less effort:
Those made with a pressure cooker and
Those made sealed in a plastic bag then cooked in a hot water bath (sous vide).
Whatever the means, the method is the same.
Step one: Balance
Stocks use a portion of bones to meat. The bones add gelatin, minerals, and a particular flavor — and body, the mouthfeel of the stock. Many argue that you can make a very good stock with bones alone. I agree. However, using science, the Modernists have been attempting to prove that flavor comes solely from the meat. One classic ratio is 3 parts bone to one part meat.
Stocks also need mirepoix, a chop of onions, carrots, celery. The classic balance is 2 parts onion for one part each celery and carrot, but let taste be your guide. How much flavor is in each ingredient? Are the onions pungent, or sweet? Are the carrots and celery bland, sweet, or flavorful? Either way, rough chop them and set them aside.
Many good stocks use a bouquet garni, most commonly with thyme, parsley stems, and a bay leaf. A few cloves of garlic and/or tomato paste are sometimes part of the flavor profile as well.
Broadly speaking you can add all of your ingredients to the pot raw or you can add them to the pot after browning them from light golden to deep brown. Kitchen wisdom is the browner the bones, meat, vegetables going in, the more flavorful the end product. Typically chicken stocks are made white and used for sauces, or browned and made for soups. Beef and pork stocks are almost always browned to bring out the flavors in the meat.
Step three: Cook under the boil
When making stock you do not want the water in the pot to move. Typically the water is between 80 – 95 degrees Celsius, or just below the boiling point. In sous vide it’s even lower; in a pressure cooker much higher (the high pressure prevents bubbles from moving what’s in the pot). When water boils the air moves everything in the pot. Eventually the water will become cloudy and the flavors will boil out, producing much less flavorful, unattractive stock. As a rule, when you see bubbles in the pot, turn down the heat.
How long to cook? That depends on whether you’re using bones. Bones add gelatin. When concentrated the gelatin adds a very specific mouthfeel to soups. That sensation in the mouth is called body. To maximize body you must boil bones preferably with either chicken feet, pigs trotters, or cow hooves — all available through the butcher. Typically you blanch them, then add them to a pot of cold water. Bring it up to the simmer — or just below the boil — and let them cook from 3 – 9 hours. The longer you boil them, the more gelatin you extract into you stock.
In my experience, the vegetables I can purchase are much less flavorful than those I grew up with as a boy. To make up for that lack of flavor I prepare two to three portions of vegetables (yes, three times what’s needed) and simmer them with the bones in stages. Placing a colander in the pot makes removing each batch easy, or you can remove them with a strainer. Either way, every three hours I replace the vegetables. I add the meat to that last batch of vegetables and cook the final two to three hours.
Step four: Strain, cool, de-fat
When the stock is ready strain it through the finest strainer you have and let the stock cool to room temperature, the refrigerate overnight. A stock with body will set like jello with a layer of fat at the top. With less to no body the fat will still float to the top. Remove it. In my experience, it has no flavor and so I throw it away.