Home-owners have been warming up to the idea of induction cooktops in recent years. Induction cooktops have the advantage of being able to heat the food faster while wasting less energy in the process. But are they for everyone? Let's see how they compare with regular cooktops that are in use in many Melbourne kitchens.
An induction cooktop generates heat by using an electromagnetic field to induce an interaction with the pan. This magnetic field oscillates (turns on and off) many times a second. This field then generates heat in a ferromagnetic pan, which is used to cook the food.
A standard cooktop uses more conventional means as a heat source. An electric stove uses electricity passed through a sizeable coiled resistor (the heating element), which generates heat. This is not unlike the way an incandescent light bulb produces light.
A gas cooktop uses an open flame directly as its heat source. This heat is then used to heat the pan, which in turn heats the food.
By its nature, generating the magnetic field in an induction cooktop is a much more efficient process than creating heat in a standard electric cooktop. The action of using electricity to generate heat through a sizeable coiled resistor is at best a lossy process, leading to wasted energy.
With a standard electric cooktop, multiple layers of heating must take place to prepare food. First, the heating element needs to heat up to the desired temperature. Then the pan (or pot) needs to be heated from the radiating energy of the heating element. Finally, the food needs to be warmed from the pan itself.
In contrast, an induction cooktop has no element that needs to be heated first. The oscillating electromagnetic field induces the heat directly in the pan. While the food is still warmed by the heat of the pan, one step has been completely eliminated.
This elimination means that the time it took to heat up the element is directly transferred to the pan. Food heats quicker, and the shortened time saves more energy.
Another interesting effect of induction cooking is that the pan cools off quickly when removed from the cooktop. This is because the heat is induced within the pan itself instead of being heated from an outside source. Once the electromagnetic energy is removed, the cookware is no longer generating heat.
As we have said, the pan actually generates the heat in an induction cooktop by the interaction of its ferromagnetic structure with the generated electromagnetic field. But for this to happen, the pan has to be made with the right material.
What this means is that aluminium cookware is not going to work with an induction cooktop. The same is true for many stainless steel pans of lower quality. A quick way to test for the right ferromagnetic properties in cookware is to use a magnet. If the magnet sticks to the cookware, there is a good chance it will work on an induction cooktop.
By comparison, standard cooktops will work with about any type of cookware, regardless of its ferromagnetic characteristics. This includes aluminium as well as all stainless steel pans.
Since induction cooktops do not have an actively heated cooktop element, they are actually safer when it comes to accidental touches. The surface stays cool, except for any heat that is radiated back from the cookware itself.
Standard cooktops generate a hot surface when they operate. This hot surface can cause pain and injury if it is accidentally touched during meal preparations.
It should be noted that a pan from an induction cooktop will still be hot if touched. While the cooktop surface itself is safer, serious injury can happen if skin comes in contact with a hot pan.
Is an induction cooktop right for you? Given that they are more energy efficient and slightly safer than a regular cooktop, the answer might be yes. However, if you have a substantial investment in cookware that isn't compatible with induction cooking methods, you may find that the expense of changing over outweighs the advantages. In the end, it probably comes down to personal preference.