Up until now, there have been two basic methods of cooking food. Both methods follow the same basic principles. In the chemical method, a combustible material—such as wood, coal, or gas—is burned to generate heat; while the electrical method accomplishes the same thing by running a current through a coil, or more recently, a halogen-filled bulb. (A third, oven-only option for generating heat needed for cooking is microwaving, which generates the heat within the food itself.) Magnetic induction is a completely different technology.
A crash course in basic physics explains how it works. When a conductor is placed in the presence of a changing magnetic field, electricity is produced in the conductor. The result is an electromagnet. In induction cooking, an electromagnet is placed under the cooking surface. When turned on, an alternating current runs through the electromagnet, producing a magnetic field. A large metal object on the surface will pick up the current and generate heat. Voila! Now we’re cooking!
The biggest difference between induction cooking and its counterparts is where the heat is generated. Gas and electric stovetops produce heat on a burner. The heat is then transferred, more or less efficiently, to a cooking vessel and its contents. In contrast, induction cook tops generate heat in the vessel itself, while the burner stays cool. Since there is no transfer of heat from burner to pan, there is virtually no wasted heat. Studies have shown that induction cooking may be up to 90% energy efficient, compared to electric and gas cooking, which are 47% and 40% energy efficient respectively. In addition to efficiency, induction cooking is the superior choice when it comes to safety issues. Because the cooking surface stays cool (i.e. room temperature) there are no more burned hands or hot pads and there is no open flame sending potentially dangerous fumes into the air. Best of all, with the heat focused in the right place, the kitchen--and the chef--stays cool and comfortable.
But the real luxury of induction cooking—the things that sets it apart as the Porsche of cook tops—is the precision and control it gives the chef. By varying the strength of the magnetic field, the heat generated in the pot responds instantly. This means water boils in half the amount of time it takes electric and gas stoves. Low temperatures work as well as high ones—meaning you can toss out your double boiler! One experiment showed chocolate chips melting at such a low temperature they held their shape until spread with a spoon. Induction warmers are great for caterers as well, since they hold low temperatures and keep food warm better than any of the alternatives.
Unfortunately there are a couple big disadvantages to induction stoves. For the pan to conduct energy it must be magnetic—that is, it must contain iron. Therefore, cast-iron and steel pots and pans are necessary. Test your cookware by passing a magnet across the pan. If the magnet sticks, the pan will work. Some cookware, made with layers of aluminum and copper for distribution, will still work beautifully on an induction cook top, as long as the surface of the pan is steel.
The second disadvantage is unavailability. For some reason, induction cooking has been slower to take off in America than it has across the Atlantic. Therefore, it’s still hard to find, and models are more expensive. (Prices start well above a thousand dollars.) However, as the market increases, look for prices to steadily fall. If you can’t wait, there are several websites where you can order an induction cook top and have it delivered to your home. Installation is relatively easy.
After using an induction cook top, it’s easy to imagine the day when we will look back on electric or gas ranges with the same astonishment and nostalgia as we do grandma’s old wood stove.