A brief guide to cooking meat so that it will be tender and juicy.
HOW LONG SHOULD A JOINT OF BEEF BE COOKED? The problem is an old one, as we know from Brillat-Savarin’s Physiology of Taste, and raises the question of what laws govern the various methods that have been devised for cooking foods. Putting aside certain exotic cases, such as the preparation of fish with acids in the Tahitian manner, in which filets are marinated in lime juice, the cook should keep in mind that cooking is fundamentally a transformation of foods by heat.
Heating with Hot Gas
This naturally leads us to ask another question: How is heat most efficiently transmitted for the purposes of cooking? Traditionally foods have been heated by means of gases, liquids, solids, and waves. Let us limit our attention here to the first of these four sets of procedures, which includes smoking, drying, braising, steaming, and oven roasting.
In the case of both drying and smoking the cooking is slow because the temperature of the hot fluid is not much above room temperature. Steaming is more efficient because the food receives both the kinetic energy of the steam and the energy resulting from the condensation of the steam on the food. Nonetheless, the upper limit of temperature in this case is 100°C [212°F]. In an oven, by contrast, the air—filled perhaps with water vapor—is able to reach much higher temperatures, whence the problem of determining the right temperature for cooking, which cooks have resolved empirically by formulas such as “twelve minutes a pound, plus ten minutes for the pot.”
What is the basis for such rules? Notice first of all that the maximum thickness of a food determines how much time is needed for it to reach a given temperature throughout. A sausage that is a mile long takes the same time to cook as one that is only a foot long as long as their diameters are equal. On the other hand, a doubling of thickness implies a quadrupling of cooking time because both the distance the heat must travel and the quantity of matter to be heated are doubled. For a spherical body, the cooking time is proportionate to the mass raised to the power of two-thirds, a relationship described by a curve that flattens out after an initially rapid rise. This approximates the old rules, which cannot be applied to foods smaller than a certain size.
Old-fashioned braising, which also relies on a hot gas, is a remarkable operation. Surface microorganisms are destroyed by browning over high heat, and the meat is then placed in a covered baking dish (classically a brazier, nowadays a casserole) and left to cook with “ashes above and ashes below,” as the best authors used to say. Although it is less than 100°C (212°F), the temperature of the heating fluid is nonetheless sufficient to evaporate the ethyl alcohol of the brandy customarily used for braising and the various aromatic compounds of the accompanying vegetables. The meat therefore cooks in a fragrant atmosphere, without losing its water, because the ambient temperature remains below the boiling point.
The Fateful Threshold
This technique is fashionable in many restaurants, where it is known as vacuum-packed low-temperature cooking. Foods are sealed in a plastic pouch that has been emptied of air and then poached at a temperature lower than 100°C (212°F). The cooking takes a long time, as in the case of the old braziers, but it makes it possible to prepare dishes in advance. This advantage was so familiar to chefs in earlier times that M. Menon specified no cooking times in his Science du Maître d’Hôtel Cuisinier (1750). He knew that as long as foods are cooked over gentle heat, the results do not greatly vary: Meats remain remarkably tender and juicy because their juices have not evaporated.
In earlier times braising was a difficult procedure to master (one had to be careful to guard against the embers suddenly bursting into flame). Today it yields remarkable results as long as one uses a preset oven and keeps in mind a few key temperatures: At 40°C (104° F) meat becomes opaque because the proteins in it, initially folded into a ball, begin to unfold before they coagulate (thus becoming denatured); at 50°C (122°F) the muscle fibers begin to contract; at 55°C (131°F) the fibrillar part of myosin (a protein that, along with actin, is essential for muscle contraction) coagulates, and collagen (a protein that gives meats their toughness) begins to dissolve; at 66°C (151°F) various other proteins coagulate; at 70°C (158°F) myoglobin no longer fixes oxygen, causing the inside of meat to turn pink; at 79°C (174°F) actin coagulates; at 80°C (176°F) the cell walls are ruptured and the meat becomes gray; at 100°C (212°F) water evaporates; and at temperatures higher than 150°C (302°F) so-called Maillard (and other) reactions produce brown and flavorful results.
What is the point of referring to these benchmarks? If the oven’s temperature control is calibrated properly, cooks can choose the exact degree of doneness that they want to achieve, without having to depend on unreliable empirical indications and without having to worry about the flare-ups that used to ruin braised dishes in the past. Naturally, meat that is cooked rare has its devotees, but they should not forget that cooking meat at low temperatures favors the proliferation of dangerous microorganisms. Low-temperature cooking is perilous, but the results are wonderful.