Low-temperature cooking is a cooking technique using

temperatures Temperature is a physical quantity that expresses quantitatively the perceptions of hotness and coldness. Temperature is measured with a thermometer. Thermometers are calibrated in various temperature scales that historically have relied on ...

in the range of about for a prolonged time to cook food. Low-temperature cooking methods include

sous vide Sous vide (; French for 'under vacuum'), also known as low-temperature, long-time (LTLT) cooking, is a method of cooking in which food is placed in a plastic pouch or a glass jar and cooked in a water bath for longer than usual cooking times (usu ...

cooking, slow cooking using a

slow cooker A slow cooker, also known as a crock-pot (after a trademark owned by Sunbeam Products but sometimes used generically in the English-speaking world), is a countertop electrical cooking appliance used to simmer at a lower temperature than o ...

, cooking in a normal oven which has a minimal setting of about , and using a

combi steamer Combi steamers (also called combi-steamers, hot-air steamers, combination steam-convection ovens, or simply combi ovens) are cooking appliances typically used in professional catering or food service operations. Combi steamers can produce both dr ...

providing exact temperature control. The traditional cooking pit also cooks food at low temperature. Cooking food by a low-temperature method does not necessarily imply that the ''internal'' temperature of the food is lower than by traditional cooking. In the American South, this style of cooking is sometimes referred to as "low and slow".

History

Low-temperature cooking has been used for a long time; evidence of its use can be found in

indigenous cultures Indigenous peoples are culturally distinct ethnic groups whose members are directly descended from the earliest known inhabitants of a particular geographic region and, to some extent, maintain the language and culture of those original people ...

Samoans Samoans or Samoan people ( sm, tagata Sāmoa) are the indigenous Polynesian people of the Samoan Islands, an archipelago in Polynesia, who speak the Samoan language. The group's home islands are politically and geographically divided between t ...

and

Tongans Tongans, a Polynesians, Polynesian group, represent more than 98% of the inhabitants of Tonga. The rest are European (the majority are British people, British), mixed European, and other Pacific Islanders. There also are several hundred Chinese i ...

slow-cook meat in large pits for celebrations and ceremonies. However, the technique was not scientifically examined until the 18th century, when

Benjamin Thompson Sir Benjamin Thompson, Count Rumford, FRS (german: Reichsgraf von Rumford; March 26, 1753August 21, 1814) was an American-born British physicist and inventor whose challenges to established physical theory were part of the 19th-century revolut ...

"described how he had left a joint of meat in a drying oven overnight and was amazed when, the next morning, he found that the meat was tender and fully cooked.". Professor Nicholas Kurti from the University of Oxford repeated these experiments in 1969, and showed that the temperature of Thompson's trial never exceeded 70 degrees Celsius (158 °F).

Theory

Meat is cooked for four reasons: to tenderise it, to provide additional flavours, to kill harmful

bacteria Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of prokaryotic microorganisms. Typically a few micrometr ...

, and to kill

parasite Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson has ...

s such as

Trichinella spiralis ''Trichinella spiralis'' is a viviparous nematode parasite, occurring in rodents, pigs, bears, hyenas and humans, and is responsible for the disease trichinosis. It is sometimes referred to as the "pork worm" due to it being typically encount ...

and Diphyllobothrium. All four can be achieved by cooking meat at high temperature for a short time, and also by cooking at low temperature for a long time. Each goal is achieved at a different temperature, and takes a different time to achieve. The lower the temperature used, the longer the cooking time. An example of slow, long cooking is Southern pulled pork BBQ.

Tenderisation

Toughness in meat is derived from several

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, res ...

s, such as

actin Actin is a family of globular multi-functional proteins that form microfilaments in the cytoskeleton, and the thin filaments in muscle fibrils. It is found in essentially all eukaryotic cells, where it may be present at a concentration of ov ...

, myosin and collagen, that combined form the structure of the muscle tissue. Heating these proteins causes them to denature, or break down into other substances, which in turn changes the structure and texture of meat, usually reducing its toughness and making it more tender. This typically takes place between over an extended period of time.

Flavour

Flavours may be enhanced by the

Maillard reaction The Maillard reaction ( ; ) is a chemical reaction between Amino acid, amino acids and Reducing sugar, reducing sugars that gives browned food its distinctive flavor. Searing, Seared steaks, fried dumplings, cookies and other kinds of biscuits, b ...

, which combines sugars and

amino acid Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although hundreds of amino acids exist in nature, by far the most important are the alpha-amino acids, which comprise proteins. Only 22 alpha a ...

s at temperatures above . Meat roasted traditionally in a hot oven has a brown crust which is generally considered desirable, caused by the Maillard reaction. Meat can be cooked at a high temperature for a short time to brown just the surface, before or after being cooked at low temperature, thus obtaining the benefits of both methods.

Bacteria

Bacteria are typically killed at temperatures of around . Most harmful bacteria live on the surface of pieces of meat which have 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. Meat which has been ground needs to be cooked at a temperature and time sufficient to kill bacteria. Poultry such as

chicken The chicken (''Gallus gallus domesticus'') is a domesticated junglefowl species, with attributes of wild species such as the grey and the Ceylon junglefowl that are originally from Southeastern Asia. Rooster or cock is a term for an adu ...

has a porous texture not visible to the eye, and can harbour pathogens in its interior even if the exterior is heated sufficiently.

Gravy

Low-temperature cooking reduces the amount of fat and juices, normally used to make gravy, rendered out of the meat. However, when using a plastic bag, little to no evaporation occurs while the meat is cooking, which results in plentiful bag juices.

Practice

Sous-vide low-temperature cooking is carried out by vacuum-sealing food in a plastic bag placed in a water bath or

with precisely controlled temperature for a long time. The food may then be browned by heating the surfaces to a much higher temperature of perhaps , using a roasting pan or a

blow torch A blowtorch, also referred to as a blowlamp, is an ambient air fuel-burning gas lamp used for applying flame and heat to various applications, usually metalworking. Early blowtorches used liquid fuel, carried in a refillable reservoir attach ...

(see recipe for cooking steaks) prior to serving. A

dishwasher A dishwasher is a machine that is used to clean dishware, cookware, and cutlery automatically. Unlike manual dishwashing, which relies heavily on physical scrubbing to remove soiling, the mechanical dishwasher cleans by spraying hot water, ty ...

has been used to cook salmon.

Temperature Table

Below is the table of minimum

temperature Temperature is a physical quantity that expresses quantitatively the perceptions of hotness and coldness. Temperature is measurement, measured with a thermometer. Thermometers are calibrated in various Conversion of units of temperature, temp ...

for different food. Beef, Pork, Veal, and Lamb: with a 3-minute rest time Ground Meat: Ham, uncooked: with a 3-minute rest time Ham, fully cooked: Poultry: Eggs: Cook until yolk & white are firm Egg Dishes: Fin Fish: or flesh is opaque & separates easily with fork Shrimp, Lobster, and Crabs: Flesh pearly & opaque Clams, Oysters, and Mussels: Shells open during cooking Scallops: Flesh is milky white or opaque and firm Leftovers and Casseroles:

References

External links

Slow-cooked roast wing rib of beef (by Heston Blumenthal)

Slow Cooked beef cheeks (by Sous Vide Australia)
* * {{DEFAULTSORT:Low-Temperature Cooking Cooking techniques