the process of cooking the surfaces of a piece of meat briefly at a high temperature until well browned, before reducing the heat and allowing cooking to finish more gently. There is one good reason for searing meat, which is that high temperatures concentrate the juices that do leak, and encourage a process known as the ‘Maillard reaction’ (see browning, section on sugar-amine browning) which gives a good flavour in the finished dish.
Culinary mythology tells a different tale, and states that searing ‘seals the juice’ into the meat, thus producing a moister end result and avoiding the loss of flavourful and nutritious matter. There is, however, no truth in this plausible theory. As McGee (1990) has demonstrated by a series of simple and elegant experiments, juice (water, water-soluble proteins and other substances, and melted fat) leaks from meat during cooking whether it has been seared or not, and experiments in the 20th century have shown that seared meat loses rather more weight (through fluid drip) than that cooked at a moderate temperature from beginning to end.
Searing, as a culinary process, originated in the 19th century when German chemist Justus von Liebig postulated, but never demonstrated, that high temperatures coagulated proteins on the surface of meat and formed a juice-trapping ‘shell’. Since 18th-century researchers thought they had isolated a water-soluble substance, which they called osmazome, held to be responsible for flavour and nutritive qualities of meat, preserving the juices was considered of prime importance (and played a large part in the development of meat extracts). Harold McGee remarks that Liebig's theory probably became popular because it offered a pseudo-scientific rationale for a new method of cooking, and thinks that the searing myth lives on because it offers a vivid and commonsensical picture of what happens to meat during cooking. Some of its persuasiveness may come from searing's resemblance to cautery, the time-honoured surgical technique of using boiling liquid, a red-hot piece of metal, a burning lens, or an electrical current to stop bleeding.
He notes that the myth has even seduced well-known experts in the field of meat science, but that cauterizing is not, in fact, a good analogy; the slow leaching of fluid from the surface of meat is very different from a steady flow of blood from a defined point. Meat proteins are arranged in bundles of long thin cells, contained in collagen sheaths; conventional methods for slicing meat usually run at right angles to these, allowing fluid to leak from the ends of innumerable cut cells. Under the influence of heat, meat proteins do coagulate from the surface inwards, but instead of welding into a watertight surface, they become shrivelled and disorganized, allowing juice to seep around the ends. After some experiments, McGee concluded that it is the thickness of the meat, and the degree to which it is done, that dictates final moisture content, and observed that fat content also influences the apparent juiciness of the meat when it is eaten.
Laura Mason has written about several aspects of British food in books including Sugar Plums and Sherbet (1998), Farmhouse Cookery (2005), and Traditional Foods of Britain (1999), which she co-authored with Catherine Brown.
McGee, Harold (1990), The Curious Cook, San Francisco: North Point Press.
