So while my formula will give you an accurate time range for your roast, your best bet is to rely on an instant-read thermometer to tell when the meat has reached your desired temperature. For the most accurate reading, insert the thermometer into the thickest part of the roast (usually the center) or the area that takes the longest to cook (such as the leg of poultry or fowl). These temperatures are a good reference for determining the doneness of the meat:
Very rare: 115°F – 118°F
Rare: 118°F – 125°F
Medium-rare: 125°F – 130°F
Medium: 130°F – 140°F
Medium-well: 140°F – 150°F
Well-done: 150°F – 180°F
Another method for judging the approximate doneness of the roast is checking the color of the juices released when you pierce it with a thermometer or skewer. If the juices are red, the roast is rare or underdone; if they are pink, it is medium; and when they run clear, the roast is fully cooked or well-done.
Resting and Carving
Once you’ve achieved your desired degree of doneness, the next step is not to slice up your roast and dig in but rather to practice patience by allowing it to rest. This allows the internal juices to distribute more evenly throughout the meat, which translates to a moister interior. Skipping this step causes the juices to drip onto the cutting board or platter, leaving the roast dry and flavorless.
For small-size cuts, the resting period is half the amount of the cooking time; for larger primal and sub-primal cuts (including a prime rib of beef, whole turkey, or leg of lamb), allow the meat to rest up to one hour before carving and serving. Don’t forget to use a very sharp knife for slicing, as a dull knife will squeeze the juices out of the meat. When ready to serve, carve your roast in the kitchen, or add a festive flair to your presentation by portioning off the tender, juicy slices tableside.
Ted Siegel has been a chef instructor at the Institute of Culinary Education in New York City since 2001. Before that he worked at Chez Panisse in California and several restaurants in New York City, including Bistro du Nord, Coco Pazzo, and Orso.