How it works: The induction cooktop

Pots and pans set over an open flame, or a glowing orange coil beneath a slab of glass-ceramic. That’s what many of us envision when we think about how to boil water, slowly melt butter, or cook delicate sauces. But present-day chefs are snuffing out flames and switching off electric burners in favor of electromagnetic fields.

The electricity passing through copper coils underneath the glass-ceramic powers induction cooktops, which first hit the U.S. market more than 25 years ago, but have gained new attention in recent years. It’s no surprise that induction cooking is growing in popularity in the U.S. and abroad: The technology offers home chefs a more efficient, precise, and safe cooking experience, and its sleek surface opens new aesthetic opportunities. Today’s kitchen designers are choosing induction cooktops as functional, stylish, and powerful appliances that complement traditional wooden cabinets and granite countertops to achieve a modern kitchen design.

But how does induction cooking work? Let’s take a look at the technology built into induction cooktops, and why it offers a more energy-efficient way to cook.

How induction heats food more evenly

Induction cooktops do not use burners or heating elements to generate heat. Instead, these cooktops use coils and magnets to produce the current that heats your cookware and cooks your food.

1. Under each cooking zone is an induction coil, usually copper. When the cooking zone is turned on, an alternating electrical current passes through the coil, creating an alternating magnetic field.

2. The magnetic field induces eddy currents (small circular electric currents) inside the metal cookware, these currents create heat within the pot or pan. Since the pan itself is creating the heat for cooking and it conducts heat very well, hot spots are eliminated.

3. The food cooks through the transfer of heat from the cookware. Because the currents heat the pot or pan (made of ferromagnetic materials) and not the cooking surface, the surface remains relatively cool, warmed only by contact with the hot pan.

4. Once the coil is turned off or the pan is moved away, the induced current ceases and stops the cooking process.

The most efficient cooktops on the market

Induction cooking can achieve temperatures up to 932 degrees Fahrenheit (500 degrees Celsius) and offers a high standard of precision. Smart controls built into the cooktop give chefs exacting control over the energy generated by the magnets, so they can bring a boil down to a simmer simply by pressing a button or turning a knob.

Induction cooking is remarkably energy efficient as well. When the magnetic field is activated, 90 percent of the energy is used to heat the cookware, reducing heat loss and saving time and money. Some induction cooktops, depending on the design and burner technology, are so efficient, in fact, they can boil two quarts of water in 3 minutes.

Glass-ceramic cooktops are durable surfaces with extremely high thermal resistance — hot pans can sit atop a glass ceramic cooktop without damaging it and the cooking zone stays relatively cool. And because the pots and pans are generating the heat — not the cooking surface — chefs can easily clean spills, splatters, and overboils. In most cases, the right cleaner and a dry cloth is all you need to keep your cooktop clean and looking like it’s brand new.

March 25, 2015


Kim Kennell
Home Tech
SCHOTT North America, Inc.