thumb|Sous vide cooking using thermal immersion circulator machines
Sous vide (; French for 'under vacuum' is a method of cooking invented by the French chef Georges Pralus in 1974, 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 (usually one to seven hours, and more than three days in some cases) at a precisely regulated temperature.
The temperature is much lower than usually used for cooking, typically around for red meat, for poultry, and higher for vegetables. The intent is to cook the item evenly, ensuring that the inside is properly cooked without overcooking the outside, and to retain moisture.
History
thumb|A video overview of the sous vide cooking process
Sous vide cooking is characterized by low-temperature cooking, a longer period of cooking than conventional cooking, a container (such as a plastic bag) that separates the food from its heating environment, and pressurized enclosure using full or partial vacuum.
Low-temperature cooking was first described by Benjamin Thompson, Count Rumford in 1799. He used air as the heat-transfer medium in his experiments while attempting to see if he could roast meat in a machine which he had created to dry potatoes. In Thompson's own words, the meat was: "Not merely eatable, but perfectly done, and most singularly well-tasted."
Preparation of food under pressure, with or without heat, was developed by American and French engineers in the mid-1960s as an industrial food preservation method. As with Rumford, the researchers learned that the food showed distinctive improvements in flavor and texture. As this method was pioneered, applying pressure to food through vacuum sealing was sometimes called "cryovacking". The pressure notably concentrated the flavors of fruits, even without cooking.
Temperature
The degree of accuracy and constancy of cooking temperature required varies with the food cooked. In some cases, it is not critical. A piece of fish will cook in 17 to 18 minutes at any temperature from to .
Regular cooking times are determined by when the center of the cooked item reaches a few degrees below the targeted temperature. Then heating should be stopped immediately. While the food rests, residual heat will continue to cook it for a while. If the heating continues, the food will be overcooked. The time taken for the center of food to reach the target temperature depends on the initial temperature, the thickness and shape of the food, and the temperature of the bath. The degree of danger posed is controversial.
Also, some evidence shows that heterocyclic aromatic amines and bisphenol-A migrate from the plastic container into the food in sous vide cooking.
Uses
thumb|upright|Compact vacuum-packing and sealing device
The sous vide method is used in many high-end gourmet restaurants by chefs such as Heston Blumenthal, It has also been used to quickly produce significant quantities of meals for hurricane evacuees.
Lower-cost units are now available in the form of a "stick", which has a clip to attach it to the side of the cooking vessel. Sous vide sticks provide a heating element, controller, and motorized impeller. The higher-cost units provide a more precise degree of control over the water temperature. Devices are becoming more user-friendly, with apps affiliated with most of the devices. Apps guide people through the cooking process, with some units having voice-control integration and Wi-Fi interfaces to control the device remotely.
See also
- Bain-marie
- Boil-in-bag
- Combi steamer
- Slow cooker
- Water jacketmechanical component utilizing the same principle for precise temperature control