The pan then heats up and cooks the food directly. And because the heat is generated inside the pan, the cooktop stays reasonably cool.
Induction cooktops are highly responsive – unlike a conventional radiant-ceramic cooktop. When you adjust the temperature, the change happens immediately.
You sometimes hear whistling or cracking sounds (especially if you’re using multi-layered saucepans) … humming when you use high power levels … and clicking when zones turn “on” or “off” or change their power levels. This is all perfectly normal.
We knew induction cooking was fast – but to see just how fast, we boiled 1 litre of water on 3 cooktops: induction, radiant-ceramic and gas.
The induction cooktop was at least 3 times faster at boiling water than the radiant-ceramic or gas models.
Approximate time to boil 1 litre of water
- Induction: 2 minutes
- Radiant-ceramic: 6 minutes
- Gas: 8 minutes
The power supply to the cooking zones works in a way that takes some getting used to. The cooking zones are organised into pairs (usually arranged as 1 pair on the left side and 1 pair on the right side).
The maximum available power is shared between the 2 cooking zones in a pair. When the “power boost” function is selected for 1 cooking zone, the additional power is made available by limiting the power of the other cooking zone in the pair. For some cooktops, the power boost function can only be used if the other cooking zone in the same pair is switched off. If you want maximum power in 2 pans, use 1 cooking zone in each pair.
For some induction cooktops, even when not using the “power boost” feature, if all cooking zones are in use at the same time, some cooking zones may be reduced in power. Check when buying whether the cooktop you want has any limitations.
Cookware used on induction cooktops must be made of ferrous (iron) materials. Induction cooktops won’t work unless you use magnetisable cookware.
Cast-iron cookware – including ceramic- or porcelain-coated cast iron – is fine. Some stainless-steel and multi-layered cookware is also suitable. But copper or aluminium pans won’t work unless they’ve got multi-layered bases with an outer layer of suitably ferrous material. Non-stick pans without an outer layer of iron won’t work either.
Most cookware will say whether it's suitable for induction cooktops.
Tip: Take a magnet with you when shopping for cookware. If the magnet sticks to the base of a pan, the pan will work on an induction cooktop.
For induction cooktops to perform most efficiently, a pan’s base must cover at least 60 to 75 percent (depending on the model) of the cooking zone and be no more than the recommended maximum diameter. The cooktop’s manual will tell you the recommended maximum diameters.
Safe with pacemakers?
The area around an induction cooktop is electromagnetically charged. It’s unlikely to affect pacemakers or other implanted electronic devices, but some brands come with a recommendation that you get advice on any possible safety concerns from the manufacturer of your pacemaker or from a doctor.