Sous-vide — French for “under vacuum — is a cooking technique of vacuum-packing food, then slow-cooking it at low temperatures. Unlike using a slow cooker, chefs using the sous-vide method cook at temperatures below the boiling point, between 104°F to 190°F.
The method was first developed in the mid-seventies by Georges Pralus in Roanne, France, and used by several innovative French chefs throughout Europe. The technique lacked popularity in America for decades because of its crude association with Stouffer’s-like boil-in-bags products, and also because of the FDA and USDA adherence to “Hazard Analysis Critical Control Points”, a food-safety program that claims food should be cooked at an internal temperature above 135°F to kill bacteria. In fact at one time New York City health officials banned Sous-vide in New York restaurants.
The concern is that low-temperatures and low-oxygen can lead to food poisoning in the form of botulism toxin; however, many chefs claim bacteria is killed off at far lower temperatures than U.S. food-safety programs suggest. The nineties saw a rebirth of sous-vide cooking thanks to molecular gastronomy breakthroughs and chefs like Ferran Adria and Heston Blumenthal. The sous-vide method is used in several gourmet restaurants under Joël Robuchon, Alessandro Stratta, Paul Bocuse, Thomas Keller, Jesse Mallgren, and may others. According to Blumenthal, “sous-vide cooking is the single greatest advancement in cooking technology in decades.”
Sous-vide cooking requires two types of equipment: a heat regulator and commercial vacuum sealer. The heat regulator most commonly used is a professional thermal immersion circulator that consists of a digital temperature gauge, and a heating coil with an attached pump. The heating coil and pump are inserted into a body of water and a temperature is set on the immersion circulator. The heating coil keeps the water at the set temperature while the pump circulates the water. One advantage of the professional thermal immersion circulator over the crock pot is that the circulator keeps water moving.
There are work-arounds to costly commercial vacuum sealers and professional thermal immersion circulators. You can use zip-lock bags with all the air removed, and a “cooking controller” — a plug-in device with an automated on/off switch that is controlled by a thermometer that you use with a crock pot or slow cooker. You put the thermometer attached to the cooking controller into the crock pot water. The drawback is lack of temperature precision.
What is all the excitement about? Meir Rinde with the Hartford Advocate described sous-vide cooking this way: “I had just watched executive chef Noel Jones whip up two plates of Colorado lamb, one cooked sous vide and the other prepared conventionally…I finally understood the hullabaloo over the cooking technique: while the pan-cooked lamb was delicious, with visible meaty fibers and the distinctive lamb flavor, the sous vide dish was like another kind of food altogether, smoothly textured, evenly rare and slightly chewy, flavorful but with a relatively light taste. It was not just meaty but somehow fleshy, as if it were at once uncooked and cooked perfectly. Think sushi. It was like eating the essence of meat.”
Others describe sous-vide cooking as rendering boneless, skinless chicken breasts as silky, and carrots as tender and sweet, but beautifully bright. Georges Pralus explained that foie gras retains its original appearance, has better texture and does not lose excess amounts of fat with the sous-vide method. To learn more sous-vide, check out Thomas Keller’s book, Under Pressure: Cooking Sous Vide or maybe something a little less daunting: Cooking Sous Vide: A Guide for the Home Cook.