When you boil sous vide down, it’s a relatively simple cooking technique that requires an investment in time and materials to figure out but has the ability to transform food. For the past several months I’ve been plunging all sorts of things in plastic bags into lukewarm water trying to figure out how sous vide works and what makes it special.
In this piece
What is Sous Vide
Sous vide is a cooking process that involves vacuum-sealing food in a plastic bag and cooking it in a hot water bath. The term itself is French for “under vacuum” and was developed for restaurants by chef Georges Pralus in the 1970s as a better way to cook foie gras. What he found was sous vide cooked foie gras kept its original appearance, had better texture and didn’t lose as much fat, as foie gras cooked with traditional methods, which is important with an expensive ingredient.
Since then restaurants have adopted the technique because once time and temperature have been figured out, it’s easy to replicate sous vide dishes. You also can keep food fresh longer once the air has been vacuumed out. The technique has become a big part of modernist cuisine and has started to migrate to home cooks with the development of reasonably priced immersion circulators that can keep water at a constant temperature for long periods of time.
How Does it Work
Sous vide use low temperatures and time to cook food evenly all the way through. To keep the juices and flavors locked in the food is vacuum-sealed before being placed in a hot water bath. The water is heated with an immersion circulator that continuously circulates the water while keeping it at a constant temperature.
To understand how sous vide works let’s compare a medium rare steak cooked sous vide and one cooked on a grill. The grilled steak is cooked for six to seven minutes a side on a medium-high grill. The sous vide steak is cooked for one to four hours at a constant 134°F.
When you cut open the steak from the grill, you can see a beautiful pink center that turns grayer as you move to the outside. This is because more of the heat from the grill has been applied to the outside of the steak than the middle. When you cut into a steak that’s been cooked sous vide it has a more consistent color from the center all the way to the outside because the heat has been applied evenly throughout the steak.
You’ll also notice that the outside of the sous vide steak is paler, and it hasn’t developed a crust. This is why most sous vide recipes include a finishing step that uses high heat to bring some color and texture to the outside of the dish.
The reason you can cook food for so long with sous vide is the cooking temperature is usually the same as the serving temperature, which means no part of the food ever gets hotter than any other part. Using low steady heat also means it takes longer for the heat to reach the center of what’s being cooked.
This is both an advantage and a disadvantage; it’s great that you can cook something for a long time without worrying about overcooking it. The downside is it can take several hours to cook something that takes twenty to thirty minutes on the grill or in the oven, so you need to plan ahead. Another advantage to sous vide is cooking food in its own juices at low temperatures helps to concentrate flavors.
How Do You Cook Sous Vide
To cook sous vide you need to have something to heat the water evenly and keep it moving around the food. Movement is key because if the water isn’t kept moving, you risk developing hot and cool spots that can produce unevenly cooked food. You’ll also need a tank or pot to hold the water. The container needs to be able to handle temperatures up to at least 185°F.
The easiest way to heat the water is to use an immersion circulator, which is a device that combines a heating element and a pump that heats and circulates the water. Over the past few years, a number of immersion circulators have come on the market in the $200 range that makes sous vide relatively affordable for home cooks.
You’ll also need to vacuum-seal whatever you’re cooking in plastic. There are a couple of basic methods for sealing food in plastic. The first is to use a straw to suck the air out of heavy-duty freezer bags. This works pretty well, especially if you remember not to stick the end of the straw too close to whatever you’re cooking. I learned this the hard way when I unexpectedly got some lamb and lemon through a straw. You can also hold a bag underwater and force the air out.
The method I ended up using after a couple of weeks of cooking a lot of sous vide is to get a vacuum-sealer that you can use to make your own bags and automatically vacuums out the air. What works about this method is how easy it is to size the bags for whatever you’re cooking and how much better it is at sucking out the air than I am.
From there it’s pretty simple, fill up your bucket, stick in your immersion circulator, bring the water up to temperature, drop in your food, set a timer, and your good to go. One of the nicest things about this type of cooking is it’s hard to overcook things; since the food never gets hotter than the temperature you set the circulator at.
Manufacturers of immersion circulators like to talk about how you can’t overcook food with sous vide. What they don’t say is that while you can’t overcook food from a temperature standpoint, the texture of food will continue to change the longer something cooks. This was apparent to me when I was working on a leg of lamb recipe. The first leg that came out at around ten hours was so succulent that you could pull it apart with a fork. A second leg that cooked for twenty some hours over two days was still good, but it started to get mealy and lost a lot of its tenderness.
So time still matters, it just doesn’t matter as much, because you have a much longer window of time to get something just right.
An unexpected and subtle downside to sous vide is food cooking underwater in plastic doesn’t smell. Personally I really like when the whole house smells like someone has been cooking all day, it helps wet my appetite and heighten my anticipation for the meal.
How’s Food Cooked Sous Vide?
The food is very good and can be noticeably different than other cooking methods. The two best things that I’ve cooked sous vide so far are pork chops and leg of lamb. The pork chops come out juicy and tender with the spice rub penetrating all the way to the bone. They’re just delicious and wonderful.
Using sous vide can completely transform a leg of lamb into something ethereal. Cooking the leg for ten hours allows the garlic, herbs, and lemon to penetrate deep into the lamb while allowing the fat to melt, so the meat is fork tender. Leg of lamb cooked sous vide and finished on the grill is one of the best ways I’ve found to make lamb.
There also have been a few things that haven’t turned out and needed more work. When things don’t work, it’s usually a texture issue, which is the biggest difference I’ve found between sous vide and traditional cooking methods. Sous vide can change the texture of food in unexpected ways. This is especially true of softer foods like salmon where it compacts the fish, making it feel firmer. I’ve also been trying to get scrambled eggs to turn out right, but haven’t been able to get the texture or the color to work yet.
I can see how using sous vide will lead to completely new dishes and new ways of looking at food. One night when I was experimenting with chicken thighs, I ended up putting a bag that had cooked for five hours straight into the fridge. When I took them out the next day, the fat and liquid had formed a chicken jelly that was delicious and is something that will probably be incorporated into all sorts of dishes.
There are lots of things I really like about sous vide, and I can’t wait to experiment with it to see how it changes dishes I already know and to see how it leads to completely new dishes. What makes sous vide special is how different it is than other cooking methods and its ability to expand how we cook.