As with the controversy in GULLIVER’S TRAVELS over how to crack open an egg, there are two opposing schools in the matter of how to grill a steak: those who salt it before cooking and those who salt it afterwards.
WHEN YOU GRILL A STEAK, naturally you salt it. But when? Before putting the meat on the grill? During cooking? Just before eating it?
Cooks are naturally inclined to respond on the basis of their own experience, but sometimes this is insufficient. As Oscar Wilde remarked, experience is the sum of all our past errors; as long as errors are not recognized, they remain alternative truths. Therefore it helps to conduct experiments in which the various parameters are controlled—the only way to cut to the heart of things, meat among them.
Some argue that introducing salt beforehand gives it time to penetrate, so that the meat is seasoned, if not quite all the way through, then at least much of the way. Others are equally convinced that salting meat before cooking causes its juices to be drawn out by osmosis. Meat is composed of cells—muscle fibers—that contain water, proteins, and all the other molecules necessary to cellular life. If the meat is placed in contact with salt at the outset, the naysayers claim, then the fact that the concentration of water in the meat is greater than in the surrounding layer of salt means that the water will osmotically migrate toward the salt, drying out the meat.
But that is not all. Not only would the meat gradually lose its juices, but during the course of their escape it would be partly boiled in them, instead of being grilled, so that it would not brown properly. It would also lose tenderness, which depends on the concentration of water in food. Some participants in the seminar on molecular gastronomy that I have been conducting in Paris for several years have mentioned a harmful effect on the internal color of the meat, noting that the juice that comes out from the meat is made up largely of blood (along with intracellular water). However, advocates of the water loss theory sometimes forget that muscle fibers are sheathed in a supporting tissue known as collagen.
The structure of different cuts of meat (beef ribs, beefsteak, pork chops, and so on) is so varied that the question must be refined. Let’s consider two simple and useful examples, a thin piece of red meat such as steak and the white meat of a fowl, and measure three things: the rate at which the salted meat discharges (“sweats”) water, the amount of weight lost, and the residual amount of salt in the meat.
Coating, Sprinkling, and Sweating
Let’s begin by considering the first question: How much juice comes out of the meat in the presence of salt? Drench pieces of red and white meat in table salt and let them sit, weighing them at regular intervals. The results probably will vary depending on the meat selected, which may have been cut along the axis of the fibers (with the grain), perpendicularly (against the grain), or diagonally (across the grain). Naturally, water will drain out more readily if the fibers have been opened up. In the case of the red meat, the type of steak matters, too. For example, a rib steak ought to lose more than a flank steak.
With flank steak we find that the discharge of water is very slow, whereas white meat such as chicken loses 1% of its weight in the first thirty minutes after salting. Of course, what happens to salted meats left to sit at room temperature is very different from what occurs during cooking, but the results are plain enough: There is no disgorging of liquid, even though the meat has been coated with salt. In the case of actual cooking, when one would season it with only a small amount of salt, the purging action would be weaker still. Thus it appears that salt has no notable effect—a provisional but nonetheless probable conclusion. You can salt your flank steak when you like, without fear of its drying out.
Turning to the second question, whether the salt penetrates the steak during cooking, consider the experiments I have conducted in collaboration with Rolande Ollitrault of the École Supérieure de Physique et Chimie in Paris and Marie-Paule Pardo and Éric Trochon of the École Supérieure de Cuisine Française. We salted the same cut of meat before and after cooking, measuring the loss of juice and, most importantly, analyzing the pieces of cooked meat with a scanning electron microscope and a device for detecting chemical elements by means of X-rays.
X-ray analysis reveals the presence of various chemical elements (notably sodium and chlorine in the case of kitchen salt), making it possible to determine whether the salt diffuses through the meat. Again, the answer is clear: Rather than penetrating to the center, it actually passes out of the meat during cooking. On the other hand, when a piece of meat that has been trimmed of fat is placed on the grill, a very small amount of metal is observed to enter the outer layer of the meat.
The nature of meats is so varied that the more subtle effects of preparation and cooking may make themselves felt only insofar as they suit our desires and answer to our illusions. “Nature,” in the sybilline words of Leonardo da Vinci (anticipating Hamlet), “is full of infinite reasons that were never in experience.” This does not mean that experimentation must be abandoned. It means that experiments must be carefully designed so that the fire of truth may be discovered beneath the smoke of subjective experience and individual opinion.