Sunday, November 24, 2013

Perfect Prime Rib

WE'RE NOT KIDDING AROUND NOW.... PERFECT PRIME RIB EVERYTIME!

With the holidays fast approaching, I thought really excellent instructions for a perfect Prime Rib bore repeating. This is courtesy of Serious Eats and the people at their Food Lab who give us clear, easy to follow and absolutely foolproof instructions to get impressive results. Once I found this, is all we ever use, after all, why mess with perfection, right? Please don't let the science of the thing get to you and prevent you from giving this method a try, stick with it and I can promise that the results will be worth it. For just the cooking directions, scroll to the bottom of the post. Here goes...

So what exactly is a Perfect Prime Rib anyway? Whether you buy prime or select, fresh or dry-aged, corn-stuffed or grass-fed, if you don't cook it right, it ain't going to be good. Here is my definition or 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 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

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 qill 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:
20091218-rib-roast-gray edges copy.jpg
I know, I know—not pretty.
Score:
    Commandment I: Perfect Crust? Check.
    Commandment II: No Gray Zone? Negative.
    Commandment III: Full-on Juiciness? Negative.
OK, 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:
20091218-rib-roast-pre-final-in-pan.jpg
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?
In order 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 3 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 8 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 that 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:
20091218-roasting-meat-graph.png
The meat that was seared first them 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 my 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

20091218-rib-roast-crust.jpg
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?
20091218-rib-roast-seared-second.jpgWell 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.
Taking what I learned from both the oven temperature testing and the searing testing into account, I now knew what I had to do to fulfill all three commandments
Taking what I learned from both the oven temperature testing and the searing testing into account, I now knew what I had to do to fulfill all three commandments: My goals should be to cook the interior of the roast as slowly as possible (IE, at as low a temperature as my oven could maintain), then sear it as quickly as possible (IE, at as high a heat as possible). Searing in a pan is not that practical for a joint bigger than a couple of ribs wide, so I needed a way to do this all in the oven.
While some recipes will have you simply pump up the oven temperature towards the end of cooking, this is sub-optimal. An oven can take 20 or 30 minutes to go from it's lowest temperature to its highest temperature setting, during which time, once again, the outer layers of beef are busy 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:
20091218-rib-roast-perfect.jpg
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.
20091218-rib-roast-no-gray.jpg
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!
Here's the steps.-
1- For best results, salt your prime rib on all surfaces with kosher salt at least 45 minutes before you start cooking it, and preferably the day before, leaving it in the fridge uncovered overnight. Initially, the salt will draw out some moisture and end up dissolving in it. Over time, this salty liquid will dissolve some meat proteins (mainly myosin), loosening its structure, and allowing the salty juices to be re-absorbed into the meat. Your meat ends up better seasoned with less salty run-off.
2- Season rib roast generously with salt and pepper on all sides and place on rack with fat cap facing up. Place in oven and cook until center of roast registers 120°F on an instant-read thermometer for medium-rare, or 135°F for medium, 3 to 4 hours. Remove roast from oven, transfer to a large plate, and tent tightly with aluminum foil. Place in a warm spot in the kitchen and allow to rest. Meanwhile, increase oven temperature to highest possible setting (500°F to 550°F).
3- Remove foil from prime rib, and place on top of rack with fat cap facing up. 10 minutes before guests are ready to be served, place roast back in hot oven and cook until well-browned and crisp on the exterior, 6-10 minutes. Remove from oven, carve, and serve immediately.
Not hard at all to follow and worth the steps. Hope you try this and add to your repertoire. I'll post side dishes to complement the meat soon and give a finished meal. Enjoy!

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