PRIME RIB
WE STARTED OUR TESTING WITH OVEN temperatures. We tested eight heating regimens, everything from 500 degrees for 40 minutes with the oven turned off and the door closed for the next two hours to a constant 200 degrees. All the prime ribs roasted at 300 degrees or above were pretty much the same. Each slice of carved beef was well done around the exterior and medium towards the center, with a beautiful medium-rare pink center. We might have been tempted to report that roasting temperature doesn't matter if we hadn't tried cooking prime rib at lower temperatures.
It's funny that we should end up preferring the prime rib roasted at 200 degrees because it certainly wasn't love at first sight. About halfway through this roast's cooking time, the meat looked virtually raw and the exterior was pale. But we changed our minds quickly as soon as we carved the first slice. This roast was as beautiful on the inside as it was anemic on the outside. Unlike the roasts cooked at higher temperatures, this one was rosy pink from the surface to the center. If was also the juiciest and most tender roast we had cooked. It was restaurant prime rib at its best.
Besides being evenly cooked, the prime rib roasted in a 200-degree oven had another thing going for it: Its internal temperatures increased only a degree or two during its resting period. (Roasts are allowed to rest when they come out of the oven both to distribute the heat evenly and to allow the juices to reabsorb back into the outer layer of meat.) Cooked to 128 degrees, it moved only to 130 degrees after a 45-minute rest.
Not so the roasts cooked at higher temperatures. Their internal temperatures increased much more dramatically out of the oven. As a matter of fact, we noticed a direct correlation between oven temperature and a roast's post-cooking temperature increase. Roasts cooked in a moderate oven (325 to 350 degrees) averaged a 14-degree jump in internal temperature while resting. Roasts cooked at 425 degrees jumped an unbelievable 24 degrees on the counter. These temperature rises make it difficult to know when a roast should be taken out of the oven.
In addition to its more stable internal temperature, the prime rib roasted at 200 degrees also lost less weight during cooking than those roasted at higher temperatures. Roasts weighing about seven pounds shed less than eight ounces when cooked at 200 degrees, but almost 11/2 pounds in a 350-degree oven and a shocking two pounds at 425 degrees. Some of the weight loss may be extra fat, but some is surely juice. This test confirmed our sense that beef roasted at 200 degrees was indeed the juiciest.
The Beef Council and other official agencies won't endorse low-temperature roasting. But after conversations with several food scientists, we determined that low-temperature roasting is safe for this cut. The odds of finding bacteria inside a prime rib roast are virtually nonexistent. (Bacteria in beef is usually limited to the exterior or to ground beef.) Just as important, the only way to guarantee that all bacteria are killed is to cook the meat to an internal temperature of 160 degrees, something we would never suggest. The only possible problem is bacteria on the exterior of the meat.
But we took care of this problem (as well as the pale exterior of the roast cooked at 200 degrees) when we decided to sear the meat on top of the stove before putting it in the oven. To make sure that the final color is attractive, sear the roast for at least eight minutes, turning it often.
Our last area of interest was aging. From past tests, we knew that dry-aging often improves the flavor and texture of steaks. However, most butchers don't dry-age beef because the hanging quarters take up too much refrigerator space and the meat loses weight during the process, forcing the butcher to make less profit or raise the price of the beef. Most butchers prefer beef that comes packaged in vacuum-sealed bags. There is no work and no weight loss.
We were still curious about dry-aging, so we ordered two prime ribs, one dry-aged, one wet-aged, from a restaurant supplier in Manhattan. Like a good, young red wine, the wet-aged beef tasted pleasant and fresh on its own. But there was no comparison to the dry-aged beef, which had a stronger, richer, gamier flavor and buttery texture.
Since dry-aged beef is so hard to find, we set out to devise our own method. It's just a matter of making room in the refrigerator and remembering to buy the roast ahead of time. Simply pat the roast dry and place it on a rack over a pan. We found that even a day or two helped concentrate the meat's flavor. For an especially tender texture and beefy flavor, let the meat age for the full week.