sous vide, French cooking technique in which food is vacuum-sealed and then slowly cooked in water heated to a low temperature. When properly done, the food cooks consistently, in its juices, maintaining moisture and tenderness.
Sous vide, meaning “under vacuum” in French, is a technique developed by French chefs in the 1970s. It was introduced to the United States by American chef Thomas Keller, a devotee of French cooking and owner of the French Laundry restaurant in California’s Napa Valley, and French chef Daniel Boulud, who was then working in New York City. In his 2008 book Under Pressure: Cooking Sous Vide, Keller praises the technique as a guarantor of consistency, a highly desired goal in any professional kitchen. With sous vide cooking, the chef or home cook can learn through experimentation the best temperature and time for any given dish, obtaining identical and replicable results.
Much of the equipment involved in cooking sous vide food in large quantity is aimed at the professional market and is expensive, although less costly equipment for home chefs is available. At the heart of the sous vide system is a vacuum sealer, with which the food to be cooked is placed inside a food-grade airtight plastic pouch and then sealed. (Home chefs may substitute a heavy-duty resealable freezer bag.) The other essential element is a circulator that attaches to the interior side of a pot and heats water to a low temperature, below simmering, then moves it constantly so that the temperature is consistent throughout the cooking process. That process may last for as little as an hour or as long as a day, depending on what is being cooked; some circulators are accompanied by computer applications that can calculate the optimal cooking time and temperature for any given food.
Many foods lend themselves to sous vide cooking. Especially popular are meat dishes such as steak and ribs, which retain their juiciness within the pouch. Seafood dishes such as salmon and shrimp, which can be easily overcooked in a pan or on a grill, do the same, as do cruciferous vegetables and beans. Chefs recommend that flaky fish not be subjected to sous vide cooking, since it can easily fall apart, while boneless poultry acquires a rubbery feel when cooked at low temperature. Meat dishes such as steak can take on a grey tone when being cooked by the low-heat immersion method, but they can be made to look more appealing by finishing them over flame.
The sous vide technique was in use in Europe for some years before it was authorized by U.S. health authorities, with scientists being concerned that food was being cooked at a low enough temperature that bacteria could flourish. This potential hazard is alleviated if the food is properly sealed, but even so, chefs recommend that before it is cooked the food in question be chilled below the danger zone (39 °F [3.8 °C]) in order to destroy any bacteria. Another safety measure is to sear meat before placing it in the pouch, killing any surface bacteria.