Sous-vide ( ; French for "under vacuum") is a cooking method in which food is placed in a plastic bag or glass bottle and then placed in a bath water or steam environment longer than normal cooking time (usually 1 to 7 hours, up to 48 or more in some cases) at an adjusted temperature accurately. Temperatures are much lower than commonly used for cooking, typically about 55 to 60 ° C (131 to 140 ° F) for meat, higher for vegetables. The goal is to cook the goods evenly, ensuring that the inside is cooked properly without overlong cooking outside, and to retain moisture.
Video Sous-vide
History
Three characteristics of sous-vide cooking, each developed separately, are low-temperature cooking, cooking with containers separating food from their heating environment, and compressed cages using full or partial vacuum.
Low temperature cooking was first described by Benjamin Thompson, Count Rumford in 1799. He used the air as a heat transfer medium in his experiments while trying to see if he could grill the meat on the machine he made to dry the potatoes. In Thompson's own words, the flesh is: "Not only edible, but perfect, and most delicious."
Food preparations under pressure, with or without heat, were developed by American and French engineers in the mid-1960s as industrial food preservation methods. As with Rumford, researchers learned that the food has a distinctive flavor and texture improvement. Because this method was pioneered, applying pressure on food through vacuum sealing is sometimes called "Cryovacking." The emphasis mainly concentrates the taste of fruits, even without cooking.
This method was adopted by Georges Pralus, a French chef, in 1974 for Restaurant Troisgros (Pierre and Michel Troisgros) in Roanne, France. He discovered that when foie gras is cooked in this way, it retains its original appearance, does not lose excess fat, and has a better texture. Another pioneer in sous-vide is Bruno Goussault, chief scientist of Traditional Food producers based in Sterling, Virginia, who examined the temperature effects on various foods and became famous for training top chefs in this method. He developed the parameters of cooking time and temperature for various foods. Goussault and Pralus independently worked on the development of sous vide in the 1970s, and eventually became collaborators. It was Goussault who pioneered marriage sealing vacuum with low temperature cooking. Pralus, considered the father of modern sous vide, is cooked at a higher temperature.
Maps Sous-vide
Important features
Sealing food in a sturdy plastic bag holds the juice and aroma which, otherwise, will be lost in the process.
Placing food in the bath water, with the temperature set at the desired final cooking temperature of the food, prevents it from overcooking, because food can not be hotter than bathing, as in bain-marie. In conventional high-cooking cooking, such as roasting or oven-baking, the food will be exposed to a much higher heat level than the desired internal cooking temperature and should be removed from high heat before it reaches the desired cooking temperature. If the food is removed from heat too late, it becomes overcooked, and if it is too quickly disposed of, it is undercooked. As a result of proper temperature control of the bath and the fact that the temperature of the bathroom is equal to the target cooking temperature, a very precise cooking control can be achieved. In addition, the temperature, and thus cooking, can be very evenly distributed throughout the food in sous-vide dishes, even with items that are irregular and very thick, given enough time.
The use of temperatures much lower than for conventional cooking is an equally important feature of sous-vide, which results in a much higher succulence at this lower temperature, since the cell wall in the food does not explode. In the case of meat cooking, hard collagen in the connective tissue can be hydrolyzed into gelatin, without heating the meat protein high enough so that they change degrees to a level that is hard texture and moisture squeezed out of the meat. By contrast, by cooking vegetables, where extreme tenderness or tenderness is seen as overcooked, the ability of the sous-vide technique to cook vegetables at temperatures well below the boiling point allows the vegetables to be thoroughly cooked (and pasteurized, if necessary) while maintaining strong or somewhat crunchy texture. While the cell wall generally will not explode, the de-polymerization of the pectic polysaccharides that connects vegetable cells together and/or gelatinization of starches in vegetables can be achieved without being too mature.
From a culinary point of view, air exclusions are secondary, but these have a practical importance. This allows cooked food to be stored, still sealed and cooled, for a considerable time, very useful for the catering industry, and that does not include oxygen from foods requiring long cooking and susceptible to oxidation, for example, fat in meat may become rancid with too much air exposure.
In addition to ensuring uniform cooking, sous-vide cooking facilitates the development of the desired organoleptic flavor and limits the flavor due to oxidation.
Temperature
The level of accuracy and determination of the required cooking temperature varies with cooked food. In some cases it is not critical. A 15-millimeter (0.6 inch) piece of fish will cook in 17 to 18 minutes at any temperature from 44 ° C (111 ° F) to 61 ° C (142 ° F). Such foods can be cooked in a slow-cooked cooker that is filled with hot water and a thermometer. But for eggs, which have proteins that change temperature at different temperatures, maintaining precision, constant temperature is more important. Confirming egg yolk is usually cooked at 63 degrees, it's hot enough to cook white without any egg yolk arrangement. Usually the tub temperature is set to 64 degrees, which means that the actual cooking temperature is 63 degrees.
Non-sous-vide cooking times are determined by when the center of the cooked item reaches several degrees below the target temperature. So the heating should be stopped immediately. While the rest of the meal, the remaining heat will continue to cook for a while. If the warming continues, the food will become too ripe. Sous-vide cooking continues until the food center has reached its target temperature. If it continues after this, the food will not be too ripe, and will not mature again after it stops heated. The time taken for the food center to reach the target temperature depends on the initial temperature, thickness and shape of the food, and the bath temperature.
One limitation of sous-vide cooking is the fact that browning (Maillard reaction) occurs at temperatures above the boiling point of water (100 Ã, Â ° C (212Ã, Â ° F)). Flavor textures and 'crust' developed with browning are generally considered highly desirable in cooking certain types of meat, such as steak. Flavors and textures produced by browning can not be obtained only by sous-vide technique. In many cases, the chef will be brown meat and other foods before placing them in bath water or after cooking sous-vide, using techniques such as roasting or burning on a very hot pot. This secondary browning is done briefly, and sometimes at higher heat than normally used, so it only affects the food surface and to avoid overcooking the interior. Similarly, fish skin can be cooked at high temperatures after sous-vide to make skin fresh.
Security
Food safety is a function of time and temperature; temperatures that are usually considered insufficient to make food safe may be very safe if treated long enough. Some sous-vide fish recipes, for example, are cooked under 55Ã, Â ° C (131Ã, Â ° F). However, people with compromised immunity should never eat unpasteurized foods properly. Women who eat sous-vide-cooked foods during pregnancy expose themselves and/or their unborn children to take risks and can thus choose to avoid unpasteurized recipes.
Clostridium botulinum bacteria can grow in food in the absence of oxygen and produce deadly botulinum toxins, so sous-vide cooking should be done under carefully controlled conditions to avoid botulism poisoning. In general, heated and served foods within four hours are considered safe, but meat cooked longer to soften should reach a minimum temperature of 55Ã, ° C (131Ã,  ° F) within four hours and then stored there. for enough time, to pasteurize meat.
Pasteurization kills bacterial botulism, but the possibility of strong botulism spores survive and reactivate after the cold remains a concern as many foods are preserved, but processed. For that reason, Baldwin's treatise determines the exact cooling requirements for "cold-cooking", so the botulism spores have no chance of growing or propagating. Pasteurized food can then be stored for up to two weeks at about 3 ° C (37 ° F) sealed in vacuum packaging.
Some plastic bags may have plasticizers with endocrine disruptor properties that are released when heated. The degree of danger posed by plasticizers, when present, is controversial. However as it raises the standard for food quality plastics, plasticizers are less common than in prior use. According to Baldwin, plastic bags made for sous-vide cooking should be food grade to limit the migration of plastic constituents into food. He added that they also must be heat resistant with a softening point of 195 Â ° F (90 Â ° C) or higher, have low gas permeability to prevent freezer burning, and have adequate mechanical strength.
Usage
The sous-vide method is used in many upscale gourmet restaurants by chefs such as Heston Blumenthal, Paul Bocuse, Michael Carlson, Thomas Keller, Grant Achatz, Ferran AdriÃÆ', JoÃÆ'ÂÂ »l Robuchon, Philippe Rochat, Alessandro Stratta, Charlie Trotter, Michael Mina Joan Roca. Amtrak also uses this method for food served on their trains, including Acela Express .
Sous-vide has become a regular on TV cooking shows like Iron Chef America and Top Chef, and even in restaurants like Panera. It has also been used to quickly produce significant amounts of food for storm evacuees. Non-professional chefs also start using sous-vide dishes.
Initially, fans used thermal-grade-grade laboratory grade circuits, often purchased used on eBay, which require very careful cleaning and, even then, are not recommended for kitchen use. Starting in 2008, Auber Instruments and Fresh Meals Solutions provide relatively inexpensive but highly accurate PID controllers with an enclosed thermocouple probe that can be used to control commercial cooking cookers, slow cookers, electric stock pans, and similar equipment. By the end of 2009, some machines intended for home use and cheaper than standard laboratory equipment went on sale.
More expensive but more universally applicable solutions are available in the form of combi steamers, which combine convection and steam cooking methods into a single device. Instead of water baths, they feature a tightly controlled steam generator system (requiring no use of enclosed pockets). It is possible to duplicate some of the effects of the sous-vide technique through the use of a beer cooler filled with warm water, checked with an accurate thermometer, and a re-sealable bag with air expended to pack food for cooking. However, the heat loss involved in this technique makes it unfeasible for long-term cooking (four hours more).
Sous vide, French for "under vacuum", implies that food should be sealed in a plastic bag with all air removed. An alternative method is to place food in an open plastic bag and partially soak the bag into water, forcing out air. This method involves clipping the open side of the bag to the side of the pot to prevent water from leaking into the hole. The goal is to get food really in contact with hot water to ensure even cooking while reducing the flavor of oxidation.
Low cost units are now available in the form of sticks that have clips to fit into the side of the cooking vessel. Sous Vide sticks provide heating elements, controllers, and motor impeller. They are available online for $ 56 or more with higher-cost units that provide a higher level of control over water temperatures. Devices are becoming easier to use, with apps affiliated with most devices, including brands like Nomiku, Anova Culinary, and Joule. The app guides people throughout the cooking step, with some units having voice control integration. They connect to WiFi to control the device remotely.
See also
- Boiled-in-Bag
- Low temperature cooking
- Slow cooker
References
Source of the article : Wikipedia
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