Anova Guide to Sous Vide Basics: WHAT Is Sous Vide?

Of all of the questions I hear regarding sous vide cooking, the most popular one without a doubt is “What is sous vide?”. Of course this makes sense that it is the FIRST question we asks when we hear this term (or really any intriguing term in connection to delicious food!) for the first time.

Picture it – you are at one of your area’s top-rated restaurants eating the most incredible double-thickness pork chop of your life. It has a crispy, flavorful, and slightly sweet crust on the outside yet is juicy, tender, and delicious through and through. You need to know how to recreate this dish at home. A server comes to check how you are doing, and you ask “HOW was this pork chop prepared? It’s blowing my mind!” They answer, “The chef ‘sous vide’ it and then it was pan seared with rosemary-garlic butter and…”

Before that server can even finish the sentence, if you haven’t ever used the technique yourself before, you are wondering “What is sous vide?”

What is sous vide?

Sous vide, pronounced “soo veed” is an amazing cooking method to add to your collection to help you achieve reliable, excellent results by following precise, tried and true guidelines that deliver every time. The name itself is derived from the French words “sous” and “vide”, directly translated to mean “under vacuum”.

What does that mean?

According to the Oxford English Dictionary, one of the definitions of vacuum and the one that applies here is “A space or container from which the air has been completely or partly removed.” When you are cooking with the sous vide method, you are usually placing your food into a plastic (zip-locking), polyethylene (vacuum seal), or silicone pouch and removing as much air as possible before sealing. As illustrated by the picture below, this can be achieved by the immersion method as opposed to a vacuum machine. Here, the pressure of the water and a helpful hand can displace the air.

We then submerge the airless-as-possible bag in a water bath held at a very specific temperature. Other containers we use to cook sous vide include glass canning jars, especially when we are cooking with liquids. Liquid takes the shape of its container and fills up the space that air would.

The “under vacuum” refers to that removal of air, which we need to do to give our ingredients as much unobstructed contact with the temperature-controlled water of the immersion circulator bath. Air is a poor conductor of heat because its molecules are both far apart and in constant motion. Water is generally accessible, inexpensive, and has a much higher thermal mass, which is the ability of a material to absorb and store heat energy.

In combination with an immersion circulator like the Anova Precision Cooker, this heat for cooking is held constant. Constant heat ensures dependable, uniform cooking and results that correspond with the target temperature of the water.

Example – if you want a medium rare steak, you would set the water temperature to somewhere in that range of doneness (like 131ºF/55ºC), drop in your sealed bag, and the constant heating would gently cook the meat from the outside in. Once the temperature in the center of that steak reached 131ºF/55ºC, the actual “cooking” would stop, but the meat would hold steady at that temperature until you were ready* to remove and serve.

*Note: while going over minimum cooking time while using the sous vide method is generally much more flexible than other cooking methods – and this is a topic we will visit in a later post – there ARE certain time limitations that must be adhered to. You cannot leave your food at cooking temperature indefinitely, especially more delicate ingredients such as seafood and vegetables.

Why do we need the bag?

The three main ways that the integrity of a food is compromised are exposure to heat, water, and oxygen.

  1. Overexposure to heat causes a chemical reaction in whatever it is you may be cooking, potentially resulting in burned and/or dried out food.
  2. Putting the food directly into the water, we can lose both not only flavor and textural integrity, but also often great deal of healthful nutrients.
  3. Oxidation via air reacting to food can result in undesirable changes in color, flavor and nutrient content, as well as growth of bacteria under certain temperate conditions.

When we use something as simple as a zip-locking or silicone bag and in a temperature controlled bath, we protect our ingredients from all of these potential issues. It allows for easy, even heat transfer from the water to the food product. Using a sealed bag creates a humid, sometimes-self-braising environment to create delicious alterations in texture, all the while preserving nutrients**.

In addition, when we cook in a bag, we need to use smaller amounts of herbs and spices. We still achieve the same delicious infused flavors, and neither water nor air dilutes the natural flavors of the main food itself.

**For more health-preserving benefits of sous vide cooking, click here.

What sous vide is NOT…

Sous vide is NOT the same as boil-in-the-bag. It is not a quick way to get an oversalted, prepared-by-a-factory meal on your table.

First of all, the water bath used in sous vide cooking is NEVER over the boiling point of 212ºF/100ºC. In fact, the range of temperatures is currently only between 77ºF/25ºC and 210ºF/99ºC using the Anova Precision Cooker, and with a 0.01º variance. This gives you so much more control over cooking time and temperature than “boil in a bag”.

Boiling in a bag also tends to produce very soft if not overcooked textures. With sous vide, you can still achieve crisp-tender vegetables and silky-as-opposed-to-curdled custards.

Sous vide is NOT the same as a slow cooker. Yes, recipes cooked using this method may take longer than traditional stovetop methods and qualify as a slower way of cooking, but the similarities end there.

With sous vide, you have much greater control over temperature and can deliver the same exact results every time you follow a particular recipe, as well as achieve rarer degrees of doneness. You can vary the amount you are cooking by changing the size of the container you are using as opposed to being limited by the size of your slow-cooker. There are no parts of your food that are left exposed to air, and therefore oxidation, as there may be with slow cooking.

Sous vide is NOT a difficult technique to learn and use. Most of the work has already been done by chefs and scientists before you, figuring out and publishing safe and basic guides of cooking temperatures and times. There are already around 1,000 recipes to try in our library, and that number is increasing almost every day. Unofficially, customers post their times and temperatures daily via our Community ForumInstagram, Facebook, and Twitter accounts.

Aaaaah – NOW I Get It! What Next?

We hope this post has helped answer the question “what is sous vide?” for you. In our next edition of the Anova Guide to Sous Vide Basics, we will be more closely examining WHY we sous vide. Convenience, precision, health benefits, and more – now that you know the WHAT, it’s time to learn about the WHY and HOW. Stay tuned, and feel free to poke around our website for a little more information if you just can’t wait!

What do you think, curious cooks and #anovafoodnerd family alike? Is there any more we could add to enrich our answer the “What is sous vide?” question? Let us know in the comments!