Sous-vide
Encyclopedia
Sous-vide
is a method of cooking
food sealed in airtight plastic bags in a water bath for a long time—72 hours is not unusual—at an accurately determined temperature much lower than normally used for cooking, typically around 60 °C or 140 °F. The intention is to cook the item evenly, not overcook the outside while still keeping the inside at the same 'doneness' and to keep the food juicier.
(of Pierre and Michel Troisgros) in Roanne, France. He discovered that when foie gras
was cooked in this manner it kept its original appearance, did not lose excess amounts of fat and had better texture.
Another pioneer in the science of sous-vide is Bruno Goussault, who further researched the effects of temperature on various foods and became well-known for training top chefs in the method. As chief scientist of Alexandria, Virginia
-based food manufacturer Cuisine Solutions, Goussault developed the parameters of cooking times and temperatures for different foods.
, sealing the food in sturdy plastic bags keeps in juices and aroma that would otherwise be lost in the process.
The use of temperatures much lower than for conventional cooking is an equally essential feature of sous-vide, resulting in much higher succulence: at these lower temperatures, cell walls in the food do not burst. In the case of meat cooking, tough collagen
in connective tissue can be hydrolyzed into gelatin, without heating the meat's protein
s high enough that they denature to a degree that the texture toughens and moisture is wrung out of the meat. In contrast, with the cooking of vegetables, where extreme tenderness or softness is seen as undesirably overcooked, the ability of the sous-vide technique to cook vegetables at a temperature below the boiling point of water allows vegetables to be thoroughly cooked (and Pasteurized, if necessary) while maintaining a firm or somewhat crisp texture. While the cell walls are generally not burst, the depolymerization of the pectic polysaccharides that connect the vegetable's cells together and/or the gelatinization of starch in the vegetable can be achieved without overcooking.
By placing the food in a water bath whose temperature is set at the desired final cooking temperature of the food, overcooking can be avoided, because the food cannot get hotter than the bath it is in. In conventional high-heat cooking, such as oven roasting or grilling, the food is exposed to heat levels that are much higher than the desired internal cooking temperature; the food must be removed from the high heat prior to its reaching the desired cooking temperature. If the food is removed from the heat too late, overshoot occurs, and if it is removed too early, undercooking results. As a result of precise temperature control of the bath and the fact that the bath temperature is the same as the target cooking temperature, very precise control of cooking can be achieved. Additionally, temperature, and thus cooking, can be very even throughout the food in sous-vide cooking, even with irregularly shaped or very thick items, given enough time.
From a culinary viewpoint the exclusion of air is secondary, but this has practical importance: it allows cooked food to be stored, still sealed and refrigerated, for considerable times, which is especially useful for the catering industry; and it excludes oxygen from food that requires long cooking and is susceptible to oxidation, e.g., fat on meat, which may become rancid
with prolonged exposure to air.
Prolonged cooking of eggs in the shell at low temperatures, for example, is usually included in the category of sous-vide, although no vacuum is involved.
One limitation of sous-vide cooking is the fact that browning (Maillard reaction
s) happens at much higher temperatures (above the boiling point of water). The flavors and "crust" texture developed by browning are generally seen as very desirable in the cooking of certain types of meat, such as a steak
. The flavors and texture produced by browning cannot be obtained with only the sous-vide technique. In some cases, meats and other foods cooked with the sous-vide technique will be browned either before or after being placed in the water bath, using techniques such as grilling
or searing
on an extremely hot pan. This secondary browning is done briefly, and sometimes at higher heat than normally used, so as to affect only the surface of the food and to avoid overcooking the interior.
,
Paul Bocuse
, Michael Carlson
, Thomas Keller
, Grant Achatz
, Ferran Adrià
, Joël Robuchon
, Alessandro Stratta
, Charlie Trotter
, Michael Mina
and others. Sous-vide has become a common feature on television cooking shows. It has also been used to quickly produce significant quantities of meals for hurricane evacuees.
Non-professional cooks are also beginning to use sous-vide cooking.
Initially, enthusiasts used laboratory-grade thermal immersion circulator
s, often bought used on eBay
and requiring very careful cleaning, even then not being recommended for kitchen use. Beginning in 2008, Auber Instruments and Fresh Meals Solutions
made available comparatively inexpensive, yet highly accurate PID controller
s with an attached thermocouple probe that could be used to control a commercial rice cooker, slow cooker, electric stock pot, or similar apparatus. In late 2009 the Sous Vide Supreme sous-vide machine (which does not circulate the cooking water) and Addélice swid
immersion circulator, both intended for home use and less expensive than laboratory-standard equipment at a few hundred US dollars, went on sale.
People experimenting with sous-vide techniques have found that the use of an insulated container such as a beer cooler filled with water a little warmer than needed as checked with an accurate thermometer, and ziploc
bags with the air sucked out to package the food for cooking, can produce much the same effect for a much lower price.
They recommend adding more insulation in the lid of the cooler to reduce the time spent monitoring and adjusting temperature.
Cooking time is often not at all critical, within limits, as the temperature is not high enough to change the nature of the food rapidly. For example fish, which becomes dry very quickly if cooked conventionally for a little longer than necessary, will remain in perfect condition for a significant time before degrading.
The time and temperature to pasteurise food may be longer than required to make it palatable, although cooking for the longer time will not impair the food. Pasteurisation is not always essential for safety if fresh uncontaminated food is cooked and eaten immediately; fresh raw foods such as sushi
and steak tartare
are widely eaten without ill effects.
Clostridium botulinum
bacteria
can grow in food in the absence of oxygen
and produce the deadly botulinum toxin
, so sous-vide cooking must be performed under carefully controlled conditions to avoid botulism
poisoning.
Generally speaking, food that is heated and served within four hours is considered safe, but meat that is cooked for longer to tenderize must reach a temperature of at least 131 °F (55 °C) within four hours and then be kept there, in order to pasteurize the meat. Pasteurization kills the botulism bacteria, but the possibility of hardy botulism spores surviving and reactivating once cool remains a concern as with many preserved foods, however processed. For that reason, Baldwin's treatise specifies precise chilling requirements for "cook-chill", so that the botulism spores do not have the opportunity to grow or propagate.
Extra precautions need to be taken for food to be eaten by people with compromised immunity
. Women eating food cooked sous vide while pregnant
may expose risk to themselves and/or their fetus and thus may choose to be more careful than usual.
is a method of cooking
Cooking
Cooking is the process of preparing food by use of heat. Cooking techniques and ingredients vary widely across the world, reflecting unique environmental, economic, and cultural traditions. Cooks themselves also vary widely in skill and training...
food sealed in airtight plastic bags in a water bath for a long time—72 hours is not unusual—at an accurately determined temperature much lower than normally used for cooking, typically around 60 °C or 140 °F. The intention is to cook the item evenly, not overcook the outside while still keeping the inside at the same 'doneness' and to keep the food juicier.
History
The method, first described by Sir Benjamin Thompson (Count Rumford) in 1799, was re-discovered by American and French engineers in the mid-1960s as an industrial food preservation method. The method was adopted by Georges Pralus in 1974 for the Restaurant TroisgrosTroisgros family
The Troisgros family are a family of French restaurateurs. Since 1957, Jean and Pierre Troisgros have played a significant role in the history of French cuisine. Pierre's son, Michel Troisgros, has played a major role since 1983. Michel Troisgros is the owner of the restaurant now called "La Maison...
(of Pierre and Michel Troisgros) in Roanne, France. He discovered that when foie gras
Foie gras
Foie gras ; French for "fat liver") is a food product made of the liver of a duck or goose that has been specially fattened. This fattening is typically achieved through gavage corn, according to French law, though outside of France it is occasionally produced using natural feeding...
was cooked in this manner it kept its original appearance, did not lose excess amounts of fat and had better texture.
Another pioneer in the science of sous-vide is Bruno Goussault, who further researched the effects of temperature on various foods and became well-known for training top chefs in the method. As chief scientist of Alexandria, Virginia
Alexandria, Virginia
Alexandria is an independent city in the Commonwealth of Virginia. As of 2009, the city had a total population of 139,966. Located along the Western bank of the Potomac River, Alexandria is approximately six miles south of downtown Washington, D.C.Like the rest of northern Virginia, as well as...
-based food manufacturer Cuisine Solutions, Goussault developed the parameters of cooking times and temperatures for different foods.
Essential features
As may also be done in traditional poachingPoaching (cooking)
Poaching is the process of gently simmering food in liquid, generally milk, stock or wine.-Utilization:Poaching is particularly suitable for delicate food, such as eggs, poultry, fish and fruit, which might easily fall apart or dry out...
, sealing the food in sturdy plastic bags keeps in juices and aroma that would otherwise be lost in the process.
The use of temperatures much lower than for conventional cooking is an equally essential feature of sous-vide, resulting in much higher succulence: at these lower temperatures, cell walls in the food do not burst. In the case of meat cooking, tough collagen
Collagen
Collagen is a group of naturally occurring proteins found in animals, especially in the flesh and connective tissues of mammals. It is the main component of connective tissue, and is the most abundant protein in mammals, making up about 25% to 35% of the whole-body protein content...
in connective tissue can be hydrolyzed into gelatin, without heating the meat's protein
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...
s high enough that they denature to a degree that the texture toughens and moisture is wrung out of the meat. In contrast, with the cooking of vegetables, where extreme tenderness or softness is seen as undesirably overcooked, the ability of the sous-vide technique to cook vegetables at a temperature below the boiling point of water allows vegetables to be thoroughly cooked (and Pasteurized, if necessary) while maintaining a firm or somewhat crisp texture. While the cell walls are generally not burst, the depolymerization of the pectic polysaccharides that connect the vegetable's cells together and/or the gelatinization of starch in the vegetable can be achieved without overcooking.
By placing the food in a water bath whose temperature is set at the desired final cooking temperature of the food, overcooking can be avoided, because the food cannot get hotter than the bath it is in. In conventional high-heat cooking, such as oven roasting or grilling, the food is exposed to heat levels that are much higher than the desired internal cooking temperature; the food must be removed from the high heat prior to its reaching the desired cooking temperature. If the food is removed from the heat too late, overshoot occurs, and if it is removed too early, undercooking results. As a result of precise temperature control of the bath and the fact that the bath temperature is the same as the target cooking temperature, very precise control of cooking can be achieved. Additionally, temperature, and thus cooking, can be very even throughout the food in sous-vide cooking, even with irregularly shaped or very thick items, given enough time.
From a culinary viewpoint the exclusion of air is secondary, but this has practical importance: it allows cooked food to be stored, still sealed and refrigerated, for considerable times, which is especially useful for the catering industry; and it excludes oxygen from food that requires long cooking and is susceptible to oxidation, e.g., fat on meat, which may become rancid
Rancidification
Rancidification is the chemical decomposition of fats, oils and other lipids . When these processes occur in food, undesirable odors and flavors can result. In some cases, however, the flavors can be desirable . In processed meats, these flavors are collectively known as "warmed over flavor"...
with prolonged exposure to air.
Prolonged cooking of eggs in the shell at low temperatures, for example, is usually included in the category of sous-vide, although no vacuum is involved.
One limitation of sous-vide cooking is the fact that browning (Maillard reaction
Maillard reaction
The Maillard reaction is a form of nonenzymatic browning similar to caramelization. It results from a chemical reaction between an amino acid and a reducing sugar, usually requiring heat....
s) happens at much higher temperatures (above the boiling point of water). The flavors and "crust" texture developed by browning are generally seen as very desirable in the cooking of certain types of meat, such as a steak
Steak
A steak is a cut of meat . Most are cut perpendicular to the muscle fibers, improving the perceived tenderness of the meat. In North America, steaks are typically served grilled, pan-fried, or broiled. The more tender cuts from the loin and rib are cooked quickly, using dry heat, and served whole...
. The flavors and texture produced by browning cannot be obtained with only the sous-vide technique. In some cases, meats and other foods cooked with the sous-vide technique will be browned either before or after being placed in the water bath, using techniques such as grilling
Grilling
Grilling is a form of cooking that involves dry heat applied to the surface of food, commonly from above or below.Grilling usually involves a significant amount of direct, radiant heat, and tends to be used for cooking meat quickly and meat that has already been cut into slices...
or searing
Searing
Searing is a technique used in grilling, baking, braising, roasting, sautéing, etc., in which the surface of the food is cooked at high temperature so a caramelized crust forms. Similar techniques, browning and blackening, are typically used to sear all sides of a particular piece of meat, fish,...
on an extremely hot pan. This secondary browning is done briefly, and sometimes at higher heat than normally used, so as to affect only the surface of the food and to avoid overcooking the interior.
Modern use
The sous-vide method is used in many high end gourmet restaurants by chefs such as Heston BlumenthalHeston Blumenthal
Heston Marc Blumenthal OBE is an English chef and owner of The Fat Duck, a three-Michelin-starred restaurant in Bray, Berkshire voted Best Restaurant in the UK by The Good Food Guide 2007 and 2009, and voted best restaurant in the world by Restaurant magazine in 2005...
,
Paul Bocuse
Paul Bocuse
Paul Bocuse is a French chef based in Lyon who is famous for the high quality of his restaurants and his innovative approaches to cuisine...
, Michael Carlson
Michael Carlson
Michael Carlson is a chef and restaurateur from Chicago, Illinois. After dropping out of culinary school, Carlson got his start in the industry working under Paul Bartolotta. From there he studied abroad in Italy under Valentino Marcattilii, and in England under Heston Blumenthal...
, Thomas Keller
Thomas Keller
Thomas Keller is an American chef, restaurateur, and cookbook writer. He and his landmark Napa Valley restaurant, The French Laundry in Yountville, California, have won multiple awards from the James Beard Foundation, notably the Best California Chef in 1996, and the Best Chef in America in 1997...
, Grant Achatz
Grant Achatz
Grant Achatz is an American chef and restaurateur often identified as one of the leaders in molecular gastronomy or progressive cuisine...
, Ferran Adrià
Ferran Adrià
Ferran Adrià i Acosta is a Catalan chef born on May 14, 1962 in L'Hospitalet de Llobregat. He was the head chef of the El Bulli restaurant in Roses on the Costa Brava, and is considered one of the best chefs in the world.-Career:...
, Joël Robuchon
Joël Robuchon
Joël Robuchon is a French chef and restaurateur. He was titled "Chef of the Century" by the guide Gault Millau in 1989 and also awarded the Meilleur Ouvrier de France in cuisine in 1976...
, Alessandro Stratta
Alessandro Stratta
Alessandro Stratta is a celebrity chef and restaurateur of mixed Italian and French heritage. Stratta played the role of Iron Chef Italian on the television show Iron Chef USA...
, Charlie Trotter
Charlie Trotter
Charlie Trotter is a chef and restaurateur.-Biography:A graduate of New Trier High School, Trotter started cooking professionally in 1982 after earning a degree in political science from the University of Wisconsin–Madison. For the next 5 years, he worked and studied in Chicago, San Francisco at...
, Michael Mina
Michael Mina
Michael Mina is an award-winning American celebrity chef, restaurateur, and cookbook author. He is the executive chef at his two namesake restaurants in San Francisco and Las Vegas, Nevada, and partners with Andre Agassi in Mina Group, a restaurant management company that owns 16 restaurants in...
and others. Sous-vide has become a common feature on television cooking shows. It has also been used to quickly produce significant quantities of meals for hurricane evacuees.
Non-professional cooks are also beginning to use sous-vide cooking.
Initially, enthusiasts used laboratory-grade thermal immersion circulator
Thermal immersion circulator
A thermal immersion circulator is an electrically powered device that circulates and heats a warm fluid kept at an accurate and stable temperature. It is used in process, environmental, microbiological, hazardous waste, and other laboratories...
s, often bought used on eBay
EBay
eBay Inc. is an American internet consumer-to-consumer corporation that manages eBay.com, an online auction and shopping website in which people and businesses buy and sell a broad variety of goods and services worldwide...
and requiring very careful cleaning, even then not being recommended for kitchen use. Beginning in 2008, Auber Instruments and Fresh Meals Solutions
made available comparatively inexpensive, yet highly accurate PID controller
PID controller
A proportional–integral–derivative controller is a generic control loop feedback mechanism widely used in industrial control systems – a PID is the most commonly used feedback controller. A PID controller calculates an "error" value as the difference between a measured process variable and a...
s with an attached thermocouple probe that could be used to control a commercial rice cooker, slow cooker, electric stock pot, or similar apparatus. In late 2009 the Sous Vide Supreme sous-vide machine (which does not circulate the cooking water) and Addélice swid
immersion circulator, both intended for home use and less expensive than laboratory-standard equipment at a few hundred US dollars, went on sale.
People experimenting with sous-vide techniques have found that the use of an insulated container such as a beer cooler filled with water a little warmer than needed as checked with an accurate thermometer, and ziploc
Ziploc
Ziploc is a brand of reusable, re-sealable zipper storage bags and containers originally developed by Dow Chemical Company, and now produced by S. C. Johnson & Son. According to Dow's website, the bags were originally test marketed in 1968....
bags with the air sucked out to package the food for cooking, can produce much the same effect for a much lower price.
They recommend adding more insulation in the lid of the cooler to reduce the time spent monitoring and adjusting temperature.
Temperature control
The degree of accuracy and constancy of cooking temperature required varies with the food cooked. In some cases it is not critical; a 15 mm-thick piece of fish will cook in 17 to 18 minutes at any temperature from 44 °C (111.2 °F) to 61 °C (141.8 °F); such food can be cooked in a switched-off slow cooker filled with hot water and a thermometer. But for an egg, which has proteins that coagulate at different temperatures, it is much more critical.Cooking times
Times vary considerably. A thin cut of fish may cook in a few minutes. Some otherwise tough cuts of meat, for example beef brisket and short ribs, benefit greatly from very long (48 to 72 hours) sous vide cooking at medium-rare temperatures of around 55 °C (131 °F), but the enzymes in chicken, and particularly fish, turn the food into mush after much shorter times.Cooking time is often not at all critical, within limits, as the temperature is not high enough to change the nature of the food rapidly. For example fish, which becomes dry very quickly if cooked conventionally for a little longer than necessary, will remain in perfect condition for a significant time before degrading.
The time and temperature to pasteurise food may be longer than required to make it palatable, although cooking for the longer time will not impair the food. Pasteurisation is not always essential for safety if fresh uncontaminated food is cooked and eaten immediately; fresh raw foods such as sushi
Sushi
is a Japanese food consisting of cooked vinegared rice combined with other ingredients . Neta and forms of sushi presentation vary, but the ingredient which all sushi have in common is shari...
and steak tartare
Steak tartare
Steak tartare is a meat dish made from finely chopped or minced raw beef. Tartare can also be made by thinly slicing a high grade of meat such as strip steak, marinating it in wine or other spirits, spicing it to taste, and then chilling it...
are widely eaten without ill effects.
Safety
Food safety is a function of both time and temperature; a temperature usually considered insufficient to render food safe may be perfectly safe if maintained for long enough.Clostridium botulinum
Clostridium botulinum
Clostridium botulinum is a Gram-positive, rod-shaped bacterium that produces several toxins. The best known are its neurotoxins, subdivided in types A-G, that cause the flaccid muscular paralysis seen in botulism. It is also the main paralytic agent in botox. C. botulinum is an anaerobic...
bacteria
Bacteria
Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...
can grow in food in the absence of oxygen
Oxygen
Oxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...
and produce the deadly botulinum toxin
Botulinum toxin
Botulinum toxin is a protein produced by the bacterium Clostridium botulinum, and is considered the most powerful neurotoxin ever discovered. Botulinum toxin causes Botulism poisoning, a serious and life-threatening illness in humans and animals...
, so sous-vide cooking must be performed under carefully controlled conditions to avoid botulism
Botulism
Botulism also known as botulinus intoxication is a rare but serious paralytic illness caused by botulinum toxin which is metabolic waste produced under anaerobic conditions by the bacterium Clostridium botulinum, and affecting a wide range of mammals, birds and fish...
poisoning.
Generally speaking, food that is heated and served within four hours is considered safe, but meat that is cooked for longer to tenderize must reach a temperature of at least 131 °F (55 °C) within four hours and then be kept there, in order to pasteurize the meat. Pasteurization kills the botulism bacteria, but the possibility of hardy botulism spores surviving and reactivating once cool remains a concern as with many preserved foods, however processed. For that reason, Baldwin's treatise specifies precise chilling requirements for "cook-chill", so that the botulism spores do not have the opportunity to grow or propagate.
Extra precautions need to be taken for food to be eaten by people with compromised immunity
Immunodeficiency
Immunodeficiency is a state in which the immune system's ability to fight infectious disease is compromised or entirely absent. Immunodeficiency may also decrease cancer immunosurveillance. Most cases of immunodeficiency are acquired but some people are born with defects in their immune system,...
. Women eating food cooked sous vide while pregnant
Pregnancy
Pregnancy refers to the fertilization and development of one or more offspring, known as a fetus or embryo, in a woman's uterus. In a pregnancy, there can be multiple gestations, as in the case of twins or triplets...
may expose risk to themselves and/or their fetus and thus may choose to be more careful than usual.
External links
- Former Microsoft Genius Masters the Culinary Art of Sous-Vide - Wired
- Cooking Sous Vide
- Cooking Sous Vide the DIY Way - Popular Science
- An introduction to sous vide cooking and training courses
- How to build your own Sous Vide rig with off the shelf parts and an Arduino microcontroller.
- Setup Guide to Sous Vide Cooking at Home - Cooking For Engineers
- The sous vide page of the wikiGullet Project - The eGullet Society for Culinary Arts & Letters
- Over 50 Sous Vide recipes and videos, detailed information about functionality, recommended cookery books and much more.