Clockwise from top: Steaks cooked to various temperatures, a perfect hanger steak, chart of moisture loss. [Photographs: J. Kenji Lopez-Alt]

If you've gone out to a fancy restaurant in the last five years or so, you've most likely eaten a protein that was cooked sous-vide in a water bath, whether you knew it or not. The process of vacuum-packing meat and cooking it in a precise temperature-controlled water bath has revolutionized the way fine-dining restaurants are run.

The introduction of the Sous-Vide Supreme, the first temperature-controlled water bath designed for home cooks promises to do the same for home cookery. Finally, anyone with a bit of cash (or a generous friend or two) can produce perfectly cooked proteins without fail—chicken with a juiciness the Colonel's wife only dreamed of, and the kind of double-thick pork chops that would've made me break out a celebratory PBR mid-service, had I been able to produce it when I was a line cook.

Unfortunately, there aren't too many practical resources for home cooks now that they've actually got the damn machines. Hopefully, this new recipe series will shed some light on sous-vide cookery basics.

A good steak is a good place to start.

It's simple enough that it can be accomplished with about 5 minutes of active work, and under an hour from start to finish. Why would anyone want to cook a steak sous-vide, you might ask? The short answer is flawless execution. When a steak is cooked via standard methods, even with a precise thermometer, you run a certain risk of over or under-cooking it.

This risk can be minimized, but it takes practice and skill—even the seasoned line cooks at Luger's, who've been turning-and-burning steaks before vegans existed, will produce the occasional slightly-too-well-done porterhouse.

By cooking your steak in a vacuum-sealed pouch at the precise temperature you want to serve it at, sous-vide cooking makes that risk a thing of the past. But there are still a number of variables involved that can give you better or worse results.

Temperature and Time

With traditional cookery, when you are exposing your meat to temperatures much hotter than their final desired temperature (say, cooking a steak to 130°F in a 550°F skillet), timing is crucial. The center of your steak is getting hotter and hotter, and it's your job as cook to take it off the flame at precisely the moment that it reaches the desired final temperature.* Miss that precise moment, and dinner is ruined.

* In some cases, carryover cooking will make this task even more difficult.

The beauty of sous-vide cooking is that since you are cooking your steak in a 130°F water bath to begin with, there is absolutely no chance your meat will ever get above that temperature. Guests are an hour late? No problem—leave the steaks in the water bath, and they'll be exactly the same an hour later.

So really, with sous-vide cooking, all you need to do is select what temperature you want to serve your meat at. As long as you give yourself enough time to allow the meat to come to that temperature (for chops and steaks, that's about 45 minutes), you can let it sit in the bath for as long as you want, with no detriment to its eating qualities.*

*Alright, alright. Really extending the cooking time—say 18 hours and above—can cause enzymes in the meat to break down too much connective tissue, delivering a mushy steak.

While temperature is really a matter of personal taste, I wanted to lay out some actual data on temperature versus eating quality. So I cooked five prime-grade New York strips at temperatures ranging from 120°F to 160°F and fed them to a group of a dozen tasters. The chart represents percentage of overall weight loss (i.e. moisture loss) that each steak experienced while cooking.

• 120°F (rare): Bright red and slippery on the interior. At this stage, the meat fibrils (which resemble bundles of juice-filled straws) have yet to expel much moisture, so in theory, this should be the juiciest steak. However, because of the softness of meat, chewing causes fibrils to push past each other instead of bursting and releasing their moisture, giving the sensation of slipperiness, or mushiness, rather than juiciness. Additionally, abundant intramuscular fat has yet to soften and render.
• 130°F (medium-rare): The meat has begun to turn pink, and is significantly firmer. Moisture loss is still minimal, at around 4%. Intramuscular fat has begun to render, which not only lubricates the meat, making it taste juicier and more tender, but it also delivers fat-soluble flavor compounds to the tongue and palate—beef at this temperature tastes significantly "beefier" than beef at 120°F. When tasted blind, even self-proclaimed rare meat lovers preferred this one, making it the most popular selection.
• 140°F (medium): Solid rosy pink, and quite firm to the touch. With over 6% moisture loss, it is still moist, but verging on dry. Prolonged chewing results in the familiar "sawdust" texture of overcooked meat. Fat is fully rendered at this stage, delivering plenty of beefy flavor. This was the second most popular choice.
• 150°F (medium-well): Pink, but verging on gray. At this stage, muscle fibrils contract heavily causing moisture level to drop precipitously, jumping all the way up to nearly 12%. Definite dryness in the mouth, with a chewy, fibrous texture. Fat has fully rendered, and has begun to collect outside the steak, carrying away flavor with it.
• 160°F (well done): Dry, gray, and lifeless. Moisture loss is up to 18%, and fat is completely rendered. What once was cow, now is dust.

So, as far as temperature goes, my strong recommendation is to stick within the 130 to 140°F range. To all you hardcore carnivores out there who insist on cooking your well-marbled, Prime-grade steaks rare, you are doing yourself a disservice: Unless it renders and softens, the fat in a well-marbled piece of meat is worthless. You may as well be eating lean, Choice, or Select-grade beef.

And as for people who cook their beef well-done, well, let's just say that you have a special place in my heart right next to Star Wars Episode 1 and that kid who stapled my arm to the table in 2nd grade.

Conclusion: For most people, 130 to 140°F is best.

Searing

Unfortunately, sous-vide cooking is deficient in one key category: it doesn't brown your meat. The browning reactions that take place to give your meat those wonderful crusty, roasted aromas only take place to a significant degree at temperatures well above 300°F, a good 170°F hotter than normal sous-vide cooking temperatures, which means that you still need to pull out the sauté pan to finish.

The key is to sear the meat as quickly as possible, to prevent any possible overcooking. Have your skillet ready and ripping hot before the meat comes out of the water bath, dry the steak thoroughly before adding it to the pan (wet meat will cool the pan down faster than dry meat), and leave it in the pan only long enough to color.

The question on my mind: some chefs pre-sear their meat before adding it to the bag, claiming that the browned flavors penetrate into the meat as it cooks in the water bath. Is this true?

Steaks just out of the bag—untreated on the left, pre-seared on the right. [Photographs: J. Kenji Lopez-Alt]

To find out, I cooked two identical steaks at 130°F, one with a pre-sear for one minute per-side in a 550°F skillet, and one without. Some of the color on the pre-seared version fades during its time in the bag. One can only hope that this is due to the fact that it has been somehow transported into the meat, reinforcing its flavor.

Same steaks, post-searing. [Photographs: J. Kenji Lopez-Alt]

These are the same two steaks after being seared for a minute per side in 550°F skillet, in hot canola oil. Visually, there's not too much distinction. And flavor-wise? In a blind tasting, tasters were split across the board on which one they preferred, and when asked to correctly identify which steak was which, they fared no better than chance.

Conclusion: Don't bother with the pre-sear—you develop plenty of flavor with just the single, post-water bath sear.

Aromatics

Next we move onto the final variable I tested: adding aromatics to the bag. For the sake of this test, those aromatics consisted of three sprigs of thyme, and a sliced garlic clove. In one bag, I placed the steak (seasoned with salt and pepper), thyme, and garlic, while in the second, I placed the same ingredients, along with 2 tablespoons of butter.

My hope was that as the butter melts, it would pick up all the fat-soluble flavor molecules from the garlic and thyme, helping to distribute their aroma evenly over the meat, and further enhancing its flavor. I also included a single, non-aromaticized steak as a control

The results were a shock: tasters unanimously picked the non-butter version as the most aromatic. Some even had trouble telling the difference between the buttered version and the version with no aromatics at all!

How could this be? I looked at sous-vide bags the steaks had been cooking in and had my answer: the bag with the buttered steak contained a large amount of highly aromatic, melted butter. Turns out the butter absorbing the fat-soluble flavor compounds in the aromatics was working against me. Rather than traveling into the meat, where I wanted it to go, it was ending up getting thrown away along with the bag.

Of course, I could use the melted butter and juices from the bag to make a tasty sauce, but if I'm going to do that, I might as well add butter-less aromatics to the steak bag, and use fresh butter and fresh aromatics for any subsequent sauce to double-up on flavor.

Conclusion: Aromatics are fine, but leave out the butter if you want to maximize their flavor.

Final Thoughts

That about wraps it up for the basics, but I want to mention one more thing. The really expensive cuts of beef—NY strip, rib eye, Porterhouse, T-bone, Filet (tenderloin)—have historically been prized for their extreme tenderness, not particularly for their flavor. On the other hand, more flavorful cuts like hanger, blade, or flatiron steak are much more difficult to cook correctly—even a tad over or undercooked, and you're left with a tough, stringy, chewy mess. But cooked properly, they can be every bit as tender as the more expensive cuts, and with more flavor to boot!

That's why those cuts are commonly referred to as "chef" cuts or "restaurant" cuts—chefs love them because they are cheap, and with proper preparation, delicious.

Well, with a sous-vide cooker, anyone can properly cook those tricky chef cuts.

$7 per pound for a hanger steak that is just as tender and tastes much better than a $16 per pound strip steak? Yes please!

Two more quick notes:

Safety: Any time you eat undercooked meat, you are running a risk of food-borne illness. Use your own judgment to weigh whether or not your pleasure is worth this risk. And if pleasure is not your priority, seriously consider becoming a vegan. At 130°F and above, bacteria will cease to multiply, but lower than this, and bacteria will multiply at an accelerated rate. If cooking your steak below 130°F, do not leave it in the water bath for any longer than four hours.

Resting: Unlike with standard high-heat cooking, which requires you to allow your steak to rest before cutting into it in order to give muscle fibrils time to relax and reabsorb juices, a steak cooked sous-vide can be served immediately after searing. Fancy that!

Now if only I could get my wife to wear that bow-tie I bought her for Christmas and serve me overpriced wine with a bit of attitude, I'd have no reason to ever set foot in a steakhouse again.

Continue here for Sous-Vide Steaks »

About the author: J. Kenji Lopez-Alt is the Chief Creative Officer of Serious Eats where he likes to explore the science of home cooking in his weekly column The Food Lab. You can follow him at @thefoodlab on Twitter, or at The Food Lab on Facebook.