What is an induction stove?
An induction stove gives you a cooking experience that's most similar to natural gas, but without the indoor air pollution. In many ways, it's a superior technology.
Natural gas is often considered the gold standard for cooking because of the instant response of a gas burner. In contrast, a traditional electric range, while powerful, is slow to respond to temperature changes.
Induction cooktops, on the other hand, combine the best of both gas and electric cooking. They’re powered by electricity, so they don’t release any combustion-related emissions into your home. Like gas, induction cooktops respond immediately to temperature changes. Induction is also much more efficient than a gas burner and is unmatched for cooking speed.
Greater awareness about the sources of indoor air pollution and better cooking performance are two major reasons for the growing popularity of induction cooking.
Even so, it’s still somewhat of a niche technology. This article will try to answer some of the common questions people have, including whether switching to induction is a good choice for you.
Stoves, ranges, cooktops, ovens, burners: cooking appliance terminology explained
Before we get into it, it’s worth clarifying the terminology that describes cooking appliances, which can get a little confusing.
An oven is a heated compartment for baking and broiling. It’s the thing you use to bake your cookies or Thanksgiving turkey.
A cooktop is a flat cooking surface with heating elements. Cooktops are usually part of a range or oven, but standalone cooktops that are installed flush with a countertop are also popular for their clean, stylish design. In Britain, these are also referred to as a hob. Induction cooktops have a durable glass-ceramic surface.
A cooktop will have one or more cooking elements. A single element of an induction cooktop might sometimes be colloquially referred to as a “burner”, even though there’s no flame.
The terms range and stove refer to the same thing: an appliance that combines an oven and cooktop. Stove seems to be the more common term where I live, but you might have a different experience. For example, KitchenAid says that range is the term most often used by retailers because a stove can also mean a wood-burning stove.
How does magnetic induction work?
An induction cooktop uses electromagnetic induction to generate heat directly in cookware. It does this with a copper coil that generates an electromagnetic field. When cookware that contains iron - such as a cast iron or stainless steel pan - is placed on top, the magnetic field induces electrical eddy currents in the pan. High electrical resistance in the pan causes it to heat up and cook whatever is in your pan.
It might seem alarming that electricity is flowing inside your pan, but all of this is extremely safe: the induced electrical field in the pan is low voltage, so you’ll never be “zapped” by it.
In fact, induction cooking is much safer than other methods. It’s also more energy efficient, fast to respond, and will boil a pot of water faster than either gas or conventional electric.
Why is induction safer than other cooking methods?
An induction element doesn’t generate heat directly, but uses a magnetic field to heat the cookware on top. While the surface of the element will get warm due to contact with the heated cookware, the temperature of the element will get nowhere near that of an open gas flame or conventional electric element.
If you’ve ever spilled cooking oil onto a hot element or accidentally let a pot holder contact an open flame, you’ll find the experience of cooking with induction to be much safer. If you spill cooking oil on an active induction element, you can just remove your pan, wait a few minutes for the element to cool down, and then wipe the spill up. The glass-ceramic surface won’t get hot enough to make your cooking oil catch fire.
Induction cooktops also have overheat protection. Temperature sensors detect when an element gets too hot and will shut the power off automatically. This might happen if you leave an empty pan on an active element or let a pot of cooking oil get too hot. On a conventional burner, your pan might warp or crack. Teflon (PTFE) pans will even release fumes that are known to have adverse health effects.
Finally, if you’ve ever owned a gas stove, you’ve probably accidentally let an unlit burner release gas into your kitchen, or wonder if you have. Even if you haven’t, basically all gas appliances leak small amounts of gas all the time. Large leaks can be catastrophic, but any amount of leaking is bad for the environment. With induction, this simply isn’t a concern.
Indoor air pollution from gas stoves
One of the big reasons why people are switching away from gas for cooking is to eliminate a major source of indoor air pollution.
Natural gas is mostly methane, which when burned perfectly will produce non-toxic carbon dioxide and water. However, natural gas isn’t pure methane, and your stove will never burn gas perfectly cleanly.
As a result, operating a gas stove will release harmful byproducts into the air you breathe, including benzene, hexane, nitrogen dioxides, and PM2.5 particulates. A growing body of scientific research is linking the use of gas stoves to health risks, including a significant proportion of childhood asthma cases.
Even if you have an exhaust hood that vents outside, that won’t protect you completely. Studies have shown that range hoods only capture some of the pollutants created by cooking.
Induction cooktops, in contrast, use electricity and therefore don’t generate any combustion byproducts, making them inherently safer for your health.
(However, it should be noted that any type of cooking, including with electric elements, can generate smoke and particulate matter.)
How does magnetic induction differ from conventional electric cooktops?
Cooking with electricity has been around for a long time. Conventional electric elements use electric resistance heating to generate heat: they pass electric current through a wire with high resistance, which causes it to heat up. This is the same process used in a toaster, hair dryer, or incandescent bulb. In fact, some glass-ceramic electric cooktops use a halogen element - which glow brightly when turned on - to generate heat.
This technology is simple and cheap, and surprisingly quite efficient. Much of the heat from a gas burner flows around the cookware and escapes into the air. Most of the energy from an electric element, on the other hand, gets transferred to the pot. Both magnetic induction and conventional electric burners have similar efficiency - about 70-80% of the energy ends up in the cooking vessel.
However, electric burners are slow to respond. This means that even though conventional electric and induction cooktops have similar efficiency, an induction element will boil a pot of water much faster because it starts to heat the pot immediately when turned on.
Conventional electric cooktops also lack the advanced safety features that their induction counterparts have.
One thing to keep in mind is that some models of electric cooktops have smooth glass-ceramic surfaces, just like induction cooktops too. However, they generate heat with a halogen element rather than a magnetic field.
What cookware is compatible with induction cooking?
Magnetic induction cooking requires cookware that is ferromagnetic, which means that it can become magnetized by an external magnetic field. Cookware that isn’t ferromagnetic won’t work on an induction cooktop.
If a magnet sticks to a pan, it’ll work with an induction cooktop. Cast iron and carbon steel are great choices for induction cooking. This includes enameled cast iron, such as the popular Le Creuset brand.
Some stainless steel cookware will work with induction, but not all. To get briefly technical, two main types of stainless steel are austenitic and ferritic. Both contain a high percentage of iron, which normally ferromagnetic, but austenitic and ferritic steels have a different atomic arrangement that cause them to be magnetic or non-magnetic.
Austenitic stainless steel is usually non-magnetic and won’t work for induction cooking. The 300 series of stainless steels, which are a chromium-nickel alloy, fall into this category. These include types 301 and 304, which are more commonly known as 18/8 and 18/10 stainless steel.
Ferritic stainless steel includes the 400 series. 430 stainless steel, more commonly known as 18/0 steel, is magnetic and is a great choice for induction cooking.
Aluminum, copper, ceramic, and pyrex cookware are non-magnetic and will not work on an induction cooktop.
However, one thing to know is that even if a piece of cookware is mostly non-magnetic, the manufacturer may add a magnetic disc to the bottom, making it compatible with induction cooking.
Just look for the induction symbol
You probably didn’t expect a metallurgy lesson in this article. Figuring out all the terms for stainless steels, including the difference between single-ply, multi-ply, fully-clad and bottom-clad cookware can be bewildering.
For example, a manufacturer may add a magnetic bottom to an otherwise non-magnetic pan, making it useful for induction cooking. Again, one way to figure out if a pan will work is to place a magnet on the bottom to see if it sticks. Another way is to simply look for the following symbol:
If you see a symbol like this, the pan will work with induction. However, this symbol isn’t universally used. For example, a carbon steel wok that you find at an Asian market - which is induction-compatible - probably won’t be marked. This is why the magnet test is the one way to be certain.
Ovens are always electric resistance
One thing to note is that if you buy an induction range - that is, a unit that includes an oven and cooktop - the oven will always be heated using electric resistance. Magnetic induction can’t be used to heat an oven cavity.
This means it’ll be the same as an older technology electric oven: there will be heating elements at the top and bottom of the oven cavity that provide heat. Some more expensive models might provide additional features, such an infrared broiler or convection fan.
Types of induction cooktops
When it comes to shopping for an induction cooktop, your choices are similar to shopping for a gas or conventional electric appliance. You can spend less than $100 for a single element unit, or thousands of dollars for a high end appliance.
It’s easy to experiment with induction cooking if you’re not sure if you’re ready to fully commit to it. A small portable unit is a relatively small investment. Even if you decide that you don’t want to upgrade your kitchen range to induction, you can keep the portable unit for use on a patio or camping - basically, anywhere you have a standard 120v outlet available.
If you’re a fan of YouTube cooking shows (like I am), you might notice that a lot of them use portable induction cooktops in their videos. There are many available, but Wirecutter lists the Duxtop 9600LS as their top pick. At the time of writing, it was listed for $115 on Amazon.
If you’re only an occasional cook, a unit like this might be all you need. However, the most common cooking appliance in homes is a range. Induction ranges combine an induction cooktop with a conventional electric oven. Here’s a typical example:
Just like with gas ranges, there are different designs for induction ranges: freestanding ranges with the controls mounted on a panel at the back, slide-in ranges (like this one) with the controls on the front, and models with one or two ovens built-in.
A last type is a built-in model, which is mounted flush with a countertop. A hole is cut in the countertop and the unit is dropped so that they sit flush with the surface. This gives you a nice clean look like this:
Electrical requirements for an induction range or cooktop
Portable induction elements plug into an ordinary 120v outlet and draw no more than 1,800 watts. This is equal to 15 amps, so if your model has a power rating of 1,800 watts, it would be best to have a 20 amp outlet so that you’re not bumping right up at the limit of the circuit breaker. 20 amp outlets are common in kitchens now, allowing high wattage appliances like microwaves and induction cooktops to run continuously while maintaining a safety margin.
To install an induction range or built-in countertop model, you will need a 240v outlet with a circuit breaker rating between 20 amps and 50 amps, depending its power requirements.