How Infrared Works

• Infrared radiation is a form of light, lying just outside the visible spectrum. As it passes through the relatively thin and sparse air molecules, it encounters relatively few of them and so loses a correspondingly small part of its energy. That changes when the light reaches a solid object, such as the surface of your food. There, the energy is rapidly converted into heat as it reaches the food and slows abruptly. In a heat lamp there's a relatively low level of infrared energy and therefore little heating. To cook food instead of warming it, a more potent energy source is required.

Char-Grilling

• One very familiar example of heating by infrared occurs in your backyard barbecue. Charcoal generates a relatively high level of conventional heating from combustion, which provides much of the cooking at low temperatures. At high temperatures, with the vents open, the coals also generate a significant amount of infrared energy. It's the infrared radiation that provides much of the browning, with its high-impact heating of the food's surface. Some gas grills provide infrared heating as well, either under the main grate or in a separate burner designed to work with the rotisserie attachment. These heat a metal grid, in much the same way as the broiler element of your home oven.

Broiling

• If you regularly use your oven's broiler, you may have noticed that it cooks foods much more quickly than a very hot oven, despite a relatively minimal difference in the actual cooking temperatures. That's the effect of the infrared energy at work. The broiler element in an electric oven emits infrared radiation when it's superheated by electrical resistance, while the broiler element in a gas oven works by superheating metal bars with the gas flame. The food is usually placed within 4 to 8 inches of the element to maximize the effect, and the intense radiation can cook a steak or a portion of fish in just a few minutes.

Infrared on the Countertop

• Because infrared radiation uses minimal energy and generates little heat anywhere but the food's surface, it's also well suited to use in countertop appliances. Many countertop cookers place a relatively low-power infrared element in a heatproof glass enclosure, making a mini-oven that can turn out perfect chickens or roasts without heating the entire kitchen. Many mid- and high-end toaster ovens also incorporate ceramic or quartz infrared elements, making those units more versatile and better suited for cooking actual meals rather than just browning your morning toast or lunchtime pizza.