It's the hottest — and coolest — thing in the kitchen these days. Induction cooktops heat only the pot or pan you're cooking in. (How? It's magic! Well, basic science. Read on.) They're really fast, just like cooking with gas, some say. Professional chefs love them. Now appliance manufacturers are betting home cooks will too.
How induction cooking works
When you cook with gas, an open flame heats the pan and the food inside it. When you cook on an electric coil or radiant cooktop, electric resistance creates heat, which is transferred to the pan and the food.
You lose a lot of that heat, whether gas or electric. It warms up your kitchen and it makes the cooktop hot.
1 In induction cooking, electricity passes through a coil of copper with magnets on its back side.
2 That creates an electromagnetic field of energy. (Electromagnetic energy is involved in radios, cell phones, hair dryers, microwaves, lightbulbs and many other things we use every day.)
3 When a pan is placed in this magnetic field (i.e., on the cooktop), its iron molecules react and begin to move very quickly — 20,000 to 50,000 times per second! — and create friction. The copper coil itself doesn't get hot. The pan becomes the source of heat that cooks the food. Only the part of the cooktop covered by the pan gets warm. No pan, no warmth.
The cooktop never glows bright red, as an electric cooktop would. It gets a little warm, the way a mug warms up when you pour in hot coffee. The cooktop starts to cool down as soon as the pan is removed from the magnetic field or when you turn it off. No heat escapes into the room.
Induction cooking has long been popular in Europe and in commercial cooking. A brief effort in this country in the 1980s never took off. So why the renaissance?
• Better technology.
• We're all foodies now, watching the TV cooking shows and seeing professional chefs use induction.
• Speed and energy savings.
• Cooks who like gas for its steady temperature and control — but who can't install gas at home — think induction is virtually the same, says Kelly China, an appliance specialist at the new Ferguson Bath, Kitchen & Lighting Gallery on N Willow Avenue in Tampa, where induction cooktops by several manufacturers are on display.
What it looks like
• An induction cooktop is made of glass (see picture on 6H), with or without a stainless-steel frame. Typical sizes are 30 and 36 inches wide.
• It's a smooth top, easily wiped clean.
• Cooktops come with four or six burners. Some manufacturers offer a hybrid: a couple of electric elements and a couple of induction cooking surfaces.
• Some manufacturers offer a single induction unit. (Viking's costs $550; it looks like a hot plate.) This can be moved around, but like the induction cooktop it requires a 220-volt line.
• Prices: $1,900 to $4,300, depending on size and features.
Plus and minus
+ Faster heating. GE estimates that 1 1/2 gallons of water will boil in 8 1/2 minutes on an induction cooktop, compared with 12 minutes on a radiant top and 13 3/4 minutes on gas. Consumer Reports says induction tops "are the fastest-heating cooktops we've ever tested."
+ Precise temperature control. It can hold a simmer or melt temperature.
+ More even cooking.
+ Energy savings, since you're cooking faster, and since you aren't heating the room or the cooktop. GE estimates induction cooking uses 90 percent of the energy produced, compared with 55 percent for gas and 65 percent for traditional electric ranges.
Wind Crest, another manufacturer, estimates that induction uses 40 percent less energy than gas or electric cooking.
+ Because the cooktop stays cool, overflows don't get baked on.
Now, the downside:
- You must use pots and pans made of magnetic metal, such as steel or cast iron. (If a refrigerator magnet sticks to the bottom of your pan, you're good to go.)
- Cost. Induction cooktops cost two to three times the price of electric or gas tops.
Pat Asarnow, 65, of North Miami Beach, bought a hybrid, a combination radiant electric and induction cooktop. Within six months she was ready for full induction.
"I was very apprehensive about going from radiant to full induction when I hadn't experienced cooking on it," said Asarnow, a retired appliance saleswoman. She wanted the comfort of the familiar. But in short order, she became a believer. "I can't imagine wanting the old one," she said.
What she loves about her all-induction Thermador: speed. Easy cleanup. The safety of a cool cooktop. The instant on/off and the precise temperature control. "This is as close to gas, in my opinion, as you can get."
• You can place a dollar bill on the cooking surface, set the pot atop it, and voila: The food cooks and the dollar bill emerges unscorched. Or lay a towel over the burner to absorb splatters from spaghetti sauce. The towel survives.
• You may see the ice cube demonstration: An ice cube in a pan on the induction surface melts and boils away, while a cube placed immediately beside it directly on the surface remains frozen. That demonstrates that the only heat is generated in the bottom of the pan, not on the cooktop. Variation: a stick of butter laid half in a cutaway pan, half on the cooking surface. Guess which half melts.
On the Web
• theinductionsite.com (detailed explanations)
• eartheasy.com/article_induction_cooking.htm (basic information)
• toolbase.org/Building-Sys tems/Appliances/induction-cooktops (technical site for the home building industry)
• wolfappliance.com (helpful video)
• geappliances.com/prod ucts/introductions/induction_cooktops/how.htm (several videos, including one starring celebrity chef Alton Brown)
• thermador.com (cutaway showing how a cooktop works)