Magnetic Fields

I first used a portable induction cooktop when cooking at Ducasse in Paris. Like most cooks in a new kitchen, I started at the garde manger—essentially the salad station. At Ducasse, it was much more than salad. We’re talkin’ $700 cans of osetra caviar, delicate langoustines, foie gras, and, when in season, $2,000-per-pound fist-sized white truffles—sensitive, expensive food that needed to be cooked carefully and kept very cold beforehand.

We used a portable induction cooktop at our station, rather than a normal stovetop, to heat things. We could move it around, it didn’t radiate heat that would have destroyed the ingredients lying nearby, and it cooked at precise temperatures, which allowed us to closely monitor the fragile foods. It was indispensable for carefully warming a foie gras emulsion, which, if it got too hot, would separate. We’d foam the emulsion with a hand blender, then spoon bubbles of warm foie gras on top of a cool foie gras mousse, while calling runners to whisk away the dishes immediately to waiting diners.

Whether they’re portable or built in, induction cooktops look just like electric smoothtop burners. But instead of heating the burner surface in order to heat your cookware and, in turn, your food, induction cooktops directly heat your cookware while leaving the cooktop surface completely cool. This may sound nonsensical, but here’s how it works: There are magnetic coils inside the cooktop that produce an electromagnetic field when electric current is passed through them. When a metal pan is placed on the burner, it reacts with the electromagnetic field, inducing a current, which is then converted to thermal energy in the pan; this energy heats up your food. Induction cooktops are considered safe. Because there’s no open flame or exposed heating element, they’re actually safer than gas or classic electric.

Stainless steel pots and pans, as well as cast iron and enameled iron cookware, all work on an induction stovetop because they’re magnetic. What won’t work, generally, are aluminum, copper, and definitely not glass, including Pyrex. For a quick compatibility test, try sticking a magnet to your cookware. If it sticks, that cookware should work; if it doesn’t, the piece probably won’t. But don’t worry, nothing will explode if you put an incompatible pot on an induction cooktop—it just won’t heat.

I tested portable induction cooktops, both single-burner models, from Sunpentown and CookTek. The former is a Taiwanese manufacturer of small appliances, and its induction cooktops are some of the most widely available in the United States, at Amazon and Target. CookTek is the only manufacturer of induction cooktops in the U.S. Ducasse in Paris uses CookTek, as does Alinea in Chicago.

With both, instead of heating foie gras foam, I boiled water for two packs of my favorite instant noodles—the super-spicy NongShim Shinramyun—and also pan-fried fish in an open cast iron skillet, the bane of home cooks’ existence because of the smell and the mess.

Induction Cooktop (SR-1881S)
By Sunpentown, $189 (silver finish)

The compact unit (12 by 3 by 14 inches) costs less in white, but for $20 more I thought it was a worthy upgrade to the sleeker silver finish.

It’s very flat, it’s lightweight, and it actually blinks if you put an incompatible piece of cookware on top—a huge timesaver if you think you’re waiting for a pot of water to boil.

The noodle water boiled in 11 minutes in a covered stainless steel pot, compared with 14 minutes on a gas burner—not a big difference.

But the showstopper came when I heated two tablespoons of water in a cast iron skillet. Almost instantly the water steamed, and in less than a minute it boiled. Meanwhile, the skillet’s handle stayed not just cool but cold. More treats were in store when I pan-fried salmon outdoors. (Remember, it’s portable!) I just plugged it into an outside outlet and let it splatter away while the skin crisped, leaving no smell or mess in my kitchen. A quick wipe was all that was needed to clean up—rather than taking apart my burners and scrubbing.

While the Induction Cooktop does have some considerate features, such as a timer (up to 99 minutes) and an automatic overheat shutoff (at 446°F), it’s a little inflexible with its temperature settings, with only nine possible choices (from 120°F to 420°F). Why would you need a temperature setting on a stove, you ask? For one, unlike gas and electric burners, an induction cooktop doesn’t show any heat source, so you can’t tell how hot it’s getting. Temperature settings give you a benchmark. It’s also great for sous-vide cooking, in which you would typically use a thermal circulator to set your water bath at a precise temperature. This allows you to go without a thermal circulator, as your water will be roughly the same temperature as your chosen stovetop setting. Todays’ recipes tell you to set a pan over low, medium, or high heat, but what’s low on one gas or electric cooktop is blazing high on another. Imagine if a standard evolved in which recipes specified a cooktop temperature? Less chance of overcooked fish or undercooked chicken. No need to play with the gas burner and infrared thermometer.

All Sunpentown induction cooktops bought directly from the manufacturer come with free induction-compatible cookware—a free frying pan or stockpot upon request.

Apogee MC-1800G
By CookTek, $1,224.50

Apogee is the newest line of CookTek induction cooktops, and is a trim 14 by 18 by 5 inches. It features a seamless slide control, rather than a knob as with their other models. It works like an iPod control, where you just drag your finger across the control panel to change settings, or press an up or down arrow button for more accuracy.

The noodle water clocked in at 8 minutes—again, not an enormous difference from gas nor from the Induction Cooktop, and the cast iron pan skillet-fried fish just as well as with the Induction Cooktop.

But where the Apogee comes out ahead is in the subtle yet powerful—and hidden—details. It has a timer that goes up to 11 hours and 59 minutes, which is great if you want to cook things like sous vide that require a lot of time. It also has temperature settings either in numbered steps—think volume controls, from 1 to 100—or actual temperature. The control panel is so fun to play with, you might be afraid that people will come screw up your settings while you’ve got a pot on the stove. But luckily the unit features a lock button, which keeps them from doing so. Again, good for sous vide, where you might leave your cooking food unattended for several hours.

And as I’ve seen at both Ducasse and Alinea, CookTek induction cooktops maintain their precise performance in the most punishing restaurant conditions.

If you’re not sure whether you want to drop the considerable cash for a CookTek cooktop, they have a 30-day trial program. The company will send you a unit for free, and if you want to keep it, they’ll send an invoice. Or you can just send it back for no charge.

When the time comes to replace your cooktops, consider induction—safer, faster, cleaner, and far more precise than gas or electric. Until then, portable induction cooktops can give you a taste of the future.