Roasted and Reverse Seared Prime Rib

This is a four-pound joint of well-marbled prime beef rib—it is not cheap. And, while my friends provide me with as many mental and philosophical riches as a man could ask for, and my wife supplies an adequate amount of emotional wealth, as a humble food writer, I do not part with dollars and cents lightly.

Thus, when I buy a quality piece of beef—and, honestly, does beef get any better than prime rib?—I have a great impetus not to mess it up, as do, I imagine, most of you.

So at The Food Lab, I've decided to get through a lifetime's worth of messings-up so that in the future, I (and hopefully you, too!) will never again serve anything but a perfectly cooked roast.

So what exactly is a perfect prime rib, anyway?

Prime Rib: The Basics

If you want to get straight into the action, there are only a few things you need to know.

Start with bone-in, well-marbled beef. Bones don't add flavor, but they do regulate temperature, increasing the amount of tender, medium-rare beef you'll get in your finished roast. And, of course, you get to gnaw on those bones when you're done. Marbling is intramuscular fat that appears as a white, spiderweb-like pattern within the meat. The more marbling, the richer and tenderer your beef will be. Though most guides recommend a pound per person when you're shopping for prime rib, this is for very hungry eaters: In reality, you'll most likely get away with three-quarters of a pound per person, or about one rib for every three people.

Season it well, and season it early if you've got time. Prime rib has plenty of flavor on its own, so there's no real need to add much more than a good heavy sprinkling of salt and pepper. If you're able to plan ahead, it's best to season your prime rib with salt at least the day before, and up to four days ahead of roasting, letting it sit on a rack in your fridge uncovered. This will allow time for the salt to penetrate and season more deeply while also drying out the surface, which will lead to better browning during roasting.

Try cooking it a little more than you think you should. I strongly believe that well-marbled prime rib is at its best when it's cooked to a minimum of medium rare, and preferably medium. Rare is great for lean cuts like tenderloin, which tend to get dry at higher temperatures, but for fatty, well-marbled cuts, you want to cook them at least to the point where the fat will start to soften and render, delivering flavor and juiciness to your mouth. Indeed, when I did a blindfolded taste test of beef cooked to various temperatures a couple of years back, all but one out of a dozen tasters preferred prime rib cooked to medium rare, even folks who initially claimed that they liked their meat rare. Give it a shot!

If you want to serve it with a sauce, I suggest using oxtails, beef shins, or soup bones (or a combination) to fortify a red wine–based jus that you can cook right alongside your prime rib in a roasting pan in the oven.

If you want to dive further into the ins and outs of prime rib, there are some crisp, succulent morsels of well-browned information to gnaw off the bones of the knowledge beast in The Food Lab's guide to buying and cooking prime rib.

Important Details About Dry-Aged Beef

For the ultimate experience in prime rib, you'll want to use dry-aged beef. There are no two ways about it: Whether you buy it from a good butcher or supermarket or age it yourself at home, it's an expensive endeavor that's gonna add to the cost of your meat. Commercially dry-aged beef will fetch upwards of $25 to $30 a pound. At home, you'll need some dedicated equipment, while also running the risk (albeit a small one, if you follow my directions) that you'll cut into your beef a few weeks down the line only to find that the controlled rot of dry-aging has turned into full-on, zombie-apocalypse-style decomposition.

But if you have the patience and the funds, nothing beats the flavor and tenderness of a perfectly dry-aged prime rib. The aging process not only improves tenderness through the action of enzymes within the meat, it also adds flavor through controlled bacterial action and the oxidation of fat. Well-aged prime rib will have a dense and meaty texture that's still incredibly tender, with a nutty, sweet aroma. Let it go long enough (28+ days), and you'll start to develop hints of Parmesan or blue cheese.

I've written an extensive guide to aging your own beef at home (all it really requires is a mini fridge, a computer CPU fan, and some patience), but since I wrote that piece, I've also tested a number of products on the market intended to help improve the odds of successful aging. Of those, two have stood out.

The SteakAger PRO 15 is a small stainless steel box that fits inside your normal fridge (I keep it in a large mini fridge, as my normal fridge is usually too full to fit it) and comes fitted with a fan, temperature and humidity monitors, and a UV light to sterilize the air as it circulates around your beef. You won't be able to fit a complete prime rib roast in there, but it's a nifty little product if you plan on aging around three ribs at a time.

The other is the Steak Locker, and this one is for serious dry-aged steak lovers only. This dedicated steak-aging refrigerator has a built-in fan and UV light, as well as trays to hold blocks of rock salt intended to help maintain humidity. A monitor in the fridge pairs with your smartphone and gives you alerts any time the temperature or humidity reaches dangerous levels. This is a feature that would have saved me several hundred dollars' worth of prime rib a couple of years ago when my aging fridge shut off over the weekend during a power outage. It's also got an ultra-sleek stainless-steel-and-glass design that's intended to be on display. This is the steak-aging fridge for people who want to communicate to their guests, "I AGE MY OWN BEEF." It's also pricey, at around $1,500—though, to be fair, it'll pay for itself after about 150 pounds of dry-aged beef, or eight to 10 full, untrimmed prime ribs.

Neither gadget is essential, but both are effective.

The Prime Rib Commandments

Whether you buy prime or select, fresh or dry-aged, corn-stuffed or grass-fed, if you don't cook it right, prime rib ain't going to be good. Here is my definition of perfection, in three commandments:

Commandment I: The Perfect Prime Rib must have a deep brown, crisp, crackly, salty crust on its exterior.

Commandment II: In the Perfect Prime Rib, the gradient at the interface between the brown crust and the perfectly medium-rare interior must be absolutely minimized (as in, I don't want a layer of gray, overcooked meat around the edges).

Commandment III: The Perfect Prime Rib must retain as many juices as possible.

Sub-Commandment i: The Perfect Prime Rib must be cookable without the use of heavy or specialized equipment, including propane or oxy-acetylene torches, sous-vide machines, or C-vap ovens.

Highs and Lows: Temperatures for Medium-Rare Prime Rib

Before I tried to start figuring out how to achieve all these goals simultaneously, it was helpful to note that when cooking beef to medium-rare, there are really only two temperatures that matter.

• 125°F (or 51.7°C) is the temperature at which beef is medium rare—that is, hot but still pink, cooked but still moist and able to retain its juices. Any higher than that and muscle fibers start to rapidly shrink, forcing flavorful juices out of the meat, and into the bottom of the roasting pan.
• 310°F (or 154.4°C) is the temperature at which the Maillard reaction—that wonderfully complicated process by which amino acids and reducing sugars recombine to form enticing roasty aromas—really begins to take off. At this range, meat will quickly brown and crisp.

Ah—a dilemma revealed itself: In order to maximize browning I had to cook the meat in a sufficiently hot oven—I tried 400°F. At the same time, I didn't want the interior to come up above 125°F.

Since a big beef roast cooks from the outside in, by the time the center had reached 125°F (that is, 120°F in the oven, followed by a 5°F rise in temperature after resting), sure there was a perfectly browned exterior, but the outermost layers had risen closer to around 165°F or 180°F, rendering them overcooked, gray, and dry, their juices having been squeezed out.

I was left with something that looked like this:

I know, I know—not pretty.

Score:

Commandment I: Perfect Crust? Check.

Commandment II: No Gray Zone? Negative.

Commandment III: Full-on Juiciness? Negative.

Okay, so what if I went to the opposite extreme, cooking the steak at a much lower temperature?

I cooked another roast in a 200°F oven until the center reached 125°F. Well, just like with boiled eggs, the temperature at which you cook is directly related to the difference in temperatures between the center, and the exterior layers.

In other words, by cooking it at a lower temperature, you make sure to minimize the volume of beef that comes above the ideal final temperature. I was able to almost completely eliminate the gray band of overcooked meat.

Of course, any browning that I was getting was also right out the window, leaving me with a roast with pale, flaccid exterior that looked like this:

I know, I know —again, not very pretty.

Score:

Commandment I: Perfect Crust? Negative.

Commandment II: No Gray Zone? Check.

Commandment III: Full-on Juiciness? Unknown.

The Myth of the Sear

Jump back a couple of decades and the solution to my dilemma would have been obvious. It was a commonly held belief (and still is, by many home cooks and professional chefs alike), that in order to help a roast, steak, or chop retain moisture, your goal should be to first sear it, creating a crust that will "lock in the juices." Now anyone who reads their Harold McGee or has ever seen juices squeeze up through the seared side of a steak after you flip it over on the grill know that this can't possibly be completely true. But what about partially true?

Could a sear actually help retain at least some of the juices?

To test this, I cooked two roasts cut from the same rib sections, with comparable surface areas, weights, and fat contents according to the following processes:

• Roast 1: Seared in a pan with three tablespoons of canola over high heat on the stovetop until a well-browned crust formed (about 15 minutes total). Transferred to a 300°F oven and roasted to an internal temperature of 120°F, removed and rested for 20 minutes (during which time the center rose to 125°F then dropped back down to 120°F).
• Roast 2: Roasted in a 300°F oven to an internal temperature of 120°F, removed and seared in a pan with three tablespoons of canola oil over high heat on the stovetop until a well-browned crust formed (about eight minutes total) and rested for 20 minutes (during which time the center rose to 125°F then dropped back down to 120°F).

If searing does in fact "lock in juices," then we would expect that the steak which was first seared then roasted should retain more juices than the steak that was first roasted then seared. Unfortunately for old wives' tales, the exact opposite is the case. I carefully weighed each roast at each step of the process to gauge the amount of moisture and fat lost during cooking. These are the results:

The meat that was seared first and then roasted lost 1.68% more juices than the one that was roasted first then seared. It's not a particularly huge difference, but the knowledge that searing conclusively does not lock in juices was certainly liberating in the ways that it allowed me to think about the recipe.

Score:

Commandment I: Perfect Crust? Check.

Commandment II: No Gray Zone? Negative.

Commandment III: Full-on Juiciness? Check.

Inside and Out

So great, you may be thinking—you can sear first or you can sear after, and it makes no difference. What's the big deal?

Well the big deal, as some of the more astute readers may have noticed in the timing above, is that if you are starting with a completely raw roast, in order to get a well-browned crust, it takes around 15 minutes in the hot pan, during which time, the meat under the surface on the outer layers of the roast is busy heating up and overcooking, just like they did when roasted in a 400°F oven.

On the other hand, in order to get a well-browned crust after the prime rib has roasted, you need only around eight minutes in the pan. Why is this?

It all has to do with water.

In order for the surface of a roast to reach temperatures above the boiling point of water (212°F), it must first become completely desiccated. When searing raw meat, about half the time it spends in the skillet is spent just getting rid of excess moisture before browning can even begin to occur. You know that vigorous sizzling sound when a steak hits a pan? That's the sound of moisture evaporating and bubbling out from underneath the meat.

On the other hand, a prime rib that has first been roasted has had several hours in a hot oven, during which time the exterior has completely dried out, making searing much more efficient, and thus giving all but the very exterior of the meat less of a chance of overcooking.

But then, I thought, 20 to 30 minutes is exactly how long a rib roast needs to rest anyhow. What if I were to first cook it at a low temperature (200°F or lower), take it out of the oven, allow it to rest while I heated the oven to its highest temperature (500 to 550°F), then pop it back in just long enough to achieve a crust?

What I achieved was nothing less than Prime Rib Perfection:

Score:

Commandment I: Perfect Crust? Check.

Commandment II: No Gray Zone? Check.

Commandment III: Full-on Juiciness? Check.

As you can see, no gray overcooked meat, a crisp brown crust, and a rosy pink from center to edge.

But wait—there's more!

The best part? I found that by cooking with this two stage method, I had a much larger window of time to serve the beef. Once I got past the initial low-temperature phase of cooking, so long as I kept the roast covered in foil, it would stay warm for over an hour. All I had to do was pop it back into its 550°F oven 8 minutes before my guests were ready to eat, and the roast would emerge hot, sizzling, and ready to carve, no need to rest it after the 500, since the only part that is being affected is the very exterior.

Family gatherings will never be the same. Now if only I could find a way to expose the rosy center under my sister's crusty exterior, we'd really have something to celebrate at the holidays!