Roasting Basics

• Roasting once meant cooking meats over an open flame, but in modern kitchens the range and wall oven have replaced the hearth for cooking. Roasting now simply means cooking your meats uncovered in the oven. Heat transfers from your oven's heating elements to the air, which in turn transfers it to the meats. It's a slow and inefficient process, because air transfers heat poorly. Increasing the intensity of the heat speeds cooking, though it won't always have a desirable effect.

High and Low Heat

• That's because of the way the muscle fibers that make up your roast respond to heat. If you've ever watched a piece of bacon shrivel on a hot griddle, you know that direct heat makes meats tighten and shrink. That effect is minimized when you roast the pork at low temperatures, but becomes stronger at high temperatures. Heat conducts slowly through the dense muscle tissues, so the outer section of the roast is likely to be overcooked by the time the middle reaches your intended temperature.

Choosing Your Cut

• High heat works better for some roasts than others. Choose tender cuts rather than tough, smaller rather than large, flat-shaped rather than round and boneless rather than bone-in roasts. If your piece of pork is tender to begin with, such as a tenderloin, it can withstand the toughening effect of high heat. Small pieces cook more quickly -- that's physics, not cooking lore -- and heat reaches the middle of a flat roast more quickly than in a thick, round one. Bones provide a juicier roast, but slow cooking because they conduct heat less efficiently than the meat itself. Leave any protective outer rind of fat in place, which shields the roast from drying.

Some Practical Tips

• Tiny pork tenderloins lend themselves well to high-heat roasting. So do loin roasts, because they're flat, tender and protected by a cap of fat. Rib roasts are relatively thick, but if you remove the bones they'll roast well at high temperatures because they're well marbled enough to handle the heat. Use a probe thermometer to tell you when your roast hits the recommended minimum temperature of 145 degrees Fahrenheit, because at high temperatures it's easy to overcook your pork. Let the roast rest for at least 15 to 20 minutes after it comes out of the oven. High heat forces the pork's juices into the center of the roast, and this resting time allows them to seep back into the rest of the meat.