Sous-vide is one of the most precise cooking methods available. Cooking (in the literal sense) is done to provide flavor, modify texture, and kill microorganisms. Most cooking methods require lots of heat and a little bit of guesswork: if you’ve ever over or under-cooked anything, you can attest to that!
Sous vide is different: you heat the food at the desired final temperature – there’s no guesswork. For example, if you want to prepare a medium-rare steak (with a center of 130°F) your sous-vide water-bath would be set to 130°F. The result is extremely consistent, whereby the temperature and ‘doneness’ of the food is exactly the same from the outside to the center – perfect every time.
Sous-vide requires a water-bath with precise temperature control. Food is placed in the water-bath, typically after being vacuum-sealed (exceptions include eggs or cooking in brine). Sealing the food allows it to fully retain flavor, moisture and nutrients during cooking, makes for easy cleanup, and allows for painless transfer between fridge (or freezer) and water-bath.
Once purvey of top chefs and restaurants who could afford laboratory grade temperature controllers, sous-vide is finally accessible to the home chef.