Free Molecular Gastronomy: Exploring the Science of Flavor by Hervé This Page A

center
    of the roast; the density of the cooked center does not differ significantly from
    that of raw meat. This means that the center has undergone little or no modi-
    fication during cooking (which is not surprising in the case of French-style
    roasts, which remain almost raw in the center) and also that the center is full
    of juices compressed by the shrinking of the collagen.
    Why, then, is it a good idea to let meat rest after cooking? Weighing the
    center and outside portions of roasts, we find that the cooked center loses more
    juice while resting than do the peripheral parts (which, having already been
    dried out, are less likely to lose any). Letting the meat rest therefore does re-
    distribute juices from the center outward so that the outer parts regain their
    tenderness. But this is not because cooking had previously forced fluids to flee
    to the center.
    Given that the juiciness of the meat depends on the amount of juice it has,
    why not use a syringe to reinject the juices that have drained out from the
    roast during cooking? Seasoned with salt and pepper, these juices would give
    the meat a taste it never had—except in the old days, when cooks used to lard
    meats before cooking with seasoned pieces of bacon.
    Roasting Beef | 49
    10
    Seasoning Steak
    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.
    w h e n y o u g r i l l a s t e a k, 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 experi-
    ence, 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 re-
    main 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 fi-
    bers—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 tender-
    ness, which depends on the concentration of water in food. Some participants
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    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