Sous vide cooking using thermal immersion circulator machines. The intent is to cook the item evenly, ensuring that the inside is properly cooked without overcooking the outside, and to retain moisture. Low-temperature cooking was first described by Benjamin Thompson, Count Rumford in 1799. Sous vide temp 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.

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. 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 sous vide is Bruno Goussault, the French chief scientist of Sterling, Virginia-based food manufacturer Cuisine Solutions. Goussault and Pralus independently worked on development of sous vide in the 1970s and eventually became collaborators. Goussault pioneered the marriage of vacuum sealing with low-temperature cooking. Pralus, considered the father of modern sous vide, cooked at higher temperatures.

A steak being prepared sous vide. Sealing the food in sturdy plastic bags retains juices and aroma that otherwise would be lost in the process. Placing the packaged food in a water bath, with the temperature set at the desired final cooking temperature of the food, prevents overcooking, because the food cannot get hotter than the bath it is in, as in bain-marie. 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 and very thick items, given enough time.