Thermador says its Freedom Induction Cooktop delivers 63 percent more usable surface area. How? Under the grey-black glass surface, there are 48 magnetic coils measuring 3 inches each. Photo: courtesy Thermador
To find out which leading manufacturers are offering induction cooktops and the pros and cons of each, click here.
Although induction technology has been around for about 70 years and has long been popular in Europe and Asia, it’s been slow to catch on with U.S. consumers—until now. Induction cooktops and ranges are one of the hottest items in home kitchen appliances today.
Once only available as freestanding or portable units, induction cooktops now can be purchased as part of kitchen range appliances with convection ovens. Popularity has grown as competition has driven down the price, making the once high-end appliances more affordable for the average homeowner.
How Induction Works
When a pan made from a magnetic metal—such as cast iron or a magnetic stainless steel alloy—is placed on the induction cooktop, electrons from the pan align with the magnetic field in the cooktop. This rapidly oscillating magnetic field creates small electrical currents, and the resistance from the pot’s molecules generates instantaneous heat.
But you don’t have to be a scientist to appreciate induction’s benefits. According to the Consumer Energy Center, induction elements use 90 percent of their energy for cooking, compared with a standard electric element, which uses about 65 percent, and gas—the least energy efficient—which uses around 50 percent. “Induction cooking is an extremely energy-efficient cooking method,” says Brian Jones, director of marketing for Sub-Zero and Wolf. “No heat is wasted because energy is supplied directly to the cooking vessel.”
All-electric cooktops are cleaner than gas, which exhausts pollutants into the air when it burns, but cooking with induction also means that the kitchen will stay cooler because little energy is lost into the room. When the ambient temperature in the kitchen is lower, the amount of ventilation necessary to expel the hot air is reduced, as is the amount of cooling required. This is especially important in restaurants or galley kitchens where constant heat from gas cooktops can become stifling.
Advantages Over Gas and Electric
The most obvious advantage that induction has over gas or electric cooktops is speed. Induction heating elements generate heat nearly instantaneously; faster than even the hottest professional gas stovetop. That greatly reduces meal prep time—for example, six quarts of water can boil in just 2 minutes. Most induction cooktop manufacturers claim up to 50 percent faster temperature response times than with electric or gas cooktops.
Induction offers not only instantaneous heat, but also instant heat adjustment and instant off. When the pan is removed, heating stops, which translates to no more boil-overs. Since an induction cooktop doesn’t hold heat itself, food can’t become scorched onto the surface as it can with a radiant electric or gas cooktop, so cleanup is easier. Pots and pans generate the heat, so the stovetop remains cool to the touch—homeowners can place their hands on the element immediately after removing a pan without being burned. In fact, when an element is turned on, no heat is produced without a pan present.
Because the magnetic energy between the cooktop and the pan generates the heat, cooking vessels must be induction-compatible, meaning they must be made from a ferrous metal such as cast iron or certain alloys of stainless steel. Favorite pots and pans made of copper, Calphalon, earthenware, or glass won’t work with induction cooktops, nor will aluminum or round-bottomed woks. If a magnet will stick to your cookware, then that pan should work with an induction cooktop.
While the need to purchase new cookware may be a negative for some, the induction cooktop’s flexibility outweighs its few disadvantages. “The induction cooktop surface enables home cooks to move the cookware anywhere on the surface, which is especially beneficial for uniquely shaped cookware or large pots and pans,” says Beatriz Sandoval, senior manager of marketing for Thermador.
Entry-level induction cooktops usually have four defined elements, much like a traditional gas or electric unit, but many manufacturers are now offering "cooking zone" technology. For example, instead of a four-element surface, Thermador’s newest induction cooktops have no predefined elements or zones; the entire cooktop surface has numerous sets of smaller magnetic coils, so a pan placed anywhere on the surface will generate heat in that location (see main image, above).
As induction’s popularity has grown, manufacturers are expanding their cooktop-only lines to include more full-size ranges to meet consumer demand. For cooks who would miss real flames licking up the sides of their sauté pan, stick with gas. But for homeowners upgrading their electric cooktop or range, induction is certainly worth a look.