Cooking Sous Vide
The reason I’m so excited about sous vide is that it results in flavors and textures and entire preparations that simply aren’t possible by any other means.
The Basics of Sous Vide Cooking While you’ll seldom see the words “sous vide” on restaurant menus, this cooking technique (which literally means “under vacuum”) was originally utilized in the early 1970s to minimize product loss when cooking foie gras. Today chefs around the world embrace sous vide for preparing a wide array of dishes. With this technique, food is vacuum sealed in a pouch and then slowly cooked at gentle temperatures. Foods become tender without losing their color, nutrients and texture. Foods are heated to the right temperature for the proper length of time. The temperature depends on the kind of food (meat, fish, and vegetables) and on personal taste (rare, medium). With all cooking techniques, including the microwave and sous vide, heat penetrates the outside surface of the food and eventually reaches the inner part, and then heats the center to the proper temperature. For example, rare beef should be cooked to an internal temperature of 125. If you roast it in an oven at 400, by the time the center of the meat reaches 125, the outside is overdone because it has been heated to 400 for a long time. Much of the beef, except for the center, is well done and gray. On the other hand, if you “roast” the beef at 125 (which nobody would do) none of it would be overdone, but it would take so long for the heat to penetrate and raise the temperature of the center to 125 that the entire piece of meat would dry out; or if you stopped roasting it too soon to keep the meat from drying out, the center would still be raw. With sous vide, you cook food at the temperature you want for the whole piece: no part is overdone or underdone. By sealing the food in a vacuumed bag, it does not dry out, lose nutrients or flavor during the long time needed to get the entire piece of food (outside and inside) to the proper temperature and hence, to the proper doneness.
Precise Temperature Control From a purely functional standpoint, cooking is the use of heat to induce chemical reactions, with different effects taking place at different temperatures. For example, the different proteins in the albumen of eggs coagulate at specific temperatures, and just a few degrees difference in cooking temperature will greatly affect just how much the egg white solidifies. The texture of the egg yolk also changes as its temperature rises. Temperature affects meat in a similar manner. Cuts with high collagen content, such as chuck and brisket, should be cooked longer and at higher temperatures to adequately break down this tough connective tissue. Cuts with little connective tissue, such as prime rib, can become tough if cooked to those same temperatures. Just a few degrees can make a difference in an expensive cut of meat, turning it from tender and moist to tough and stringy. This is another benefit of sous vide cooking, as higher temperatures are not required. The art of sous vide cooking is in determining the perfect core temperature the food needs to reach in order to achieve the desired taste and texture. For a dish that features an egg with creamy custard like texture, one chef might cook that egg to a core temperature of 143, while another may prefer 146. While this temperature difference might seem insignificant, the finished eggs will be drastically different from each other, making each chef’s dish unique. The importance of precise temperature control is critical to sous vide cooking. Cooking times with the sous vide technique are affected by several factors, including the initial temperature of the food, its mass and heat transfer characteristics. The low temperatures for long periods of time are what making the tantalizing results of sous vide possible. As a result, it will take some testing and experience to determine the proper amount of time needed for a dish to reach the desired doneness. In general, cooking time is affected by three factors: the core temperature you wish to cook the dish to; the heat transfer characteristics of the food; and the amount of food that will be cooked at one time. Also, the greater the cooking liquid to food ratio, the faster each portion of food will reach the proper core temperature. It is recommended that when cooking sous vide, the cooking pouches be completely covered with liquid; also, there should be sufficient room for the pouches and cooking liquid to circulate freely. Another important advantage of slow, low temperature sous vide cooking: it becomes much harder to overcook food by leaving it in longer than necessary. Once a dish reaches the desired temperature, it will take a lot more time to keep cooking the food; in other words, it can be kept at that temperature (moist, delicious and ready to serve) for a longer period without shrinking, drying out or becoming tough. This is particularly advantageous when cooking expensive cuts of meat, such as Kobe Wagyu beef.
Enhancing Presentation To complement and enhance the melt-in-your-mouth tenderness of sous vide meat dishes, many chefs finish the food by briefly grilling or searing it to create the familiar aromas and flavors that come only with high-heat cooking. The interior of the food will remain exceptionally tender and moist, and there will be very little, if any, of the shrinkage that occurs with traditionally grilled and roasted meats.
While you can’t inadvertently overcook a dish with the sous vide method; you can undercook it if you remove it from the heated cooking liquid before it reaches the desired core temperature. Disclaimer: The information presented above is for informational purposes only. As with any cooking method, proper food safety procedures should be followed.