Have you ever noticed how the roast beef sliced at a deli is rare to medium-rare almost to the very edge of the meat? That is the result of low-temperature, slow cooking, and it is the standard method for commercial cooking. When you cook meat at a high temperature, 400°F (205°C) and above, the outside dries out and overcooks by the time the center is medium rare. And at that point, the medium-rare area is only about an inch-and-a-half in diameter.

Cook the roast at a moderate temperature, 300°F to 375°F (150°C to 190°C), and the medium-rare area will be larger, but there will still be a substantial portion of overcooked meat on the outside. Cook it at 200°F (95°C) to the same center temperature, and it will be a beautiful medium rare almost to the edge.

Another strong argument for slow roasting is that meats begin to lose water much more rapidly above 120°F (50°C). One study showed that a 6-pound roast lost more than 2 pounds when cooked at 500°F (260°F). Is it any wonder the meat industry relies on slow roasting? It cannot afford to see a third of each product evaporate for the sake of speed.

Now, one argument the people give for roasting at a high temperature is to allow for the formation of a beautiful, flavorful crispy brown crust. Shirley Corriher, author of Cookwise (Canada, UK), and Chris Kimball, publisher of Cook’s Illustrated have come up with a slow-cooking method that also produced a delicious brown crust.

First, they sear all sides of the meat in a hot skillet on top of the stove. They season the roast with a little salt and pepper, place it on a rack in a roasting pan and slip it into a 200°F oven, where it cooks until it reaches an internal temperature of 110°F (45°C). At that point, they turn the oven up to 500°F and continue cooking until the internal temperature of the meat reaches 130°F (55°C), which should take only 10 or 15 minutes more. Raising the temperature after most of the cooking is done gives you a deep brown crust very fast, Corriher says, because protein- and sugar-laden juices that came to the surface during cooking evaporated, leaving a high concentration of proteins and sugars that brown quickly.

Eight hours may be a little long, though, for all but the largest roasts. A roast cooked at 200°F is going to take about twice as long as one roasted at 350°F. But you will really have to rely on your trusty meat thermometer to know when to turn up the heat and when the roast is done. It should rest outside the oven for 20 to 30 minutes before you carve it.