Low-temperature cooking is a cooking technique, a variant of roasting, which is claimed to produce more tender and tasty results than traditional high-temperature roasting. In low-temperature cooking, the food to be cooked (typically a red meat, such as beef) is cooked for a long period of time (in the region of 10–20 hours) at a low temperature (in some cases, as low as 55 °C, 131 °F). The technique, developed in the 1970s by Georges Pralus for the Troisgros restaurant, is now favoured by avant-garde chefs including Marc Veyrat and Heston Blumenthal.
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Meat is cooked for four reasons — to tenderise it, to provide additional flavours, to kill harmful bacteria, and to kill parasites such as Trichinella spiralis and Diphyllobothrium. While all four can be achieved by cooking a piece of meat at high temperature for a short period of time, this is not the only way; it can also be achieved by cooking at low temperature for a long period of time. Each goal is achieved at a different temperature, and takes a different length of time to achieve. There is an inverse relationship between temperature and time; low and slow, or high and fast, with Southern BBQ being a excellent example of low and slow - taking a tough cut of meat and producing pulled pork BBQ by cooking low (at low temperature) and slow (for a long duration).
Several proteins that form the structure of muscle tissue (meat) give it toughness: actin, myosin and collagen. Heating these proteins causes them to denature, or break down into other substances, which changes the structure and texture of meat, usually reducing its toughness (increasing tenderness). This typically happens between 55 °C and 65 °C (131 °F and 149 °F) over an extended period of time.
Flavours may be enhanced by the Maillard reaction, which combines sugars and amino acids at temperatures above 100 °C (212 °F). A roast meat typically has a brown crust, which is caused by such a reaction and is generally considered desirable. Meat can be braised before being cooked at low temperature to obtain the benefits of both methods.
Bacteria are typically killed at temperatures of around 68 °C (154 °F). Most harmful bacteria live on the surface of pieces of meat (assuming the meat has not been ground or shredded before cooking). As a result, for unprocessed steaks or chops of red meat it is usually safe merely to bring the surface temperature of the meat to this temperature and hold it there for a few minutes. See food safety
Since low-temperature cooking reduces the amount of fat rendered out of the meat, producing gravy from the meat may be more difficult. However, gravy may be unnecessary, since the meat is often sufficiently moist when cooked using this technique.
A typical process for low-temperature cooking would involve briefly raising the temperature of the outside of the food to a high temperature (e.g., 400 °F), using a roasting pan or even a blow torch.[1] The food would normally then be placed into a low-temperature oven for a long duration, before being rested (cooled) briefly prior to serving. One eccentric variant of low-temperature cooking involves placing the food in a dishwasher. [2]