INDUCTION HOB AND TEMPERATURE CONTROL
INDUCTION HOB AND TEMPERATURE CONTROL
There has been a lot of interesting talk about an induction hob. Let
me say that I've owned one for about 2 1/2 years – and I'm in love
with it. I purchased my unit from the Home Shopping Network, on sale
for $79. It was their Wolfgang Puck model – with timer, watt control
(1400 to 400), and temperature control (400-150 F). It was so useful
that I pulled out an electric burner from my GE stove and placed the
unit over the hole, and that is where it now resides. I haven't used
my stove top since. I don't believe that that unit is available
anymore on HSN, but it is available on Amazon.com for $99. Not that
you should buy it, as in 2 1/2 years there may be improvements that
are implemented on other makes and models.
There seems to be a complaint about the temperature control on
induction hobs. Well I also find that it can be a problem, but later,
in this writing (don't peek!), I'll share with you a TRICK that I use
that helps. Perhaps you can make use of it too.
EXPERIMENT 1 – [Easy and quick to do]
Take your largest induction ready frying pan which you have used
before on your unit and put a 1/4 inch layer of water in it. Place it
on your induction hob and turn the unit on but immediately set the
temperature to 150° (or the lowest temperature that your unit allows),
Notice how the small bubbles begin to quickly form. In particular
notice where they form – perhaps not quite in the center of the pan.
Notice the shape of the bubble area. Is it a circular disk? A small
dot? Or are there a number of areas where the bubbling begins to
happen. Notice how the bubbles are becoming more active and are
beginning to grow in size, till eventually an area of the bubbles is
giving off steam and appears to be boiling. Notice how large and
where that area is (it may not be in the center - Bummer.) Notice the
water surface in the rest the pan. Have bubbles formed? Is it
boiling? Watch the progression until the entire bottom of the pan
contains boiling water. [BACK TO THIS IN A MOMENT]
The copper wound exciter disk (the induction-cooker element; the wire
coil) which is just under the surface of the ceramic top may vary in
size depending upon which induction hob you own. You, as I, don't
probably know the size of this disk – or even if it is correctly
centered, so by watching the bubble pattern it will give us a valuable
[Here is an exposed photo of a wire coil element:
All elements are not this size. Some elements are composed of
concentric rings that excite independently based upon settings and pre-
programmed actions. Your element, if you own an induction hob, is
probably much smaller in diameter.]
BUT WAIT, SOMETHING IS WRONG!
In our experiment we were looking at water beginning to boil in our
frying pan. But we have the temperature set to 150°. THAT CAN'T BE,
for water boils at 212°. If our setting is accurate, water shouldn't
be boiling at all. It should just heat up to 150° and maintain that
temperature. Perhaps something is wrong with our setting -- not
Because the entire bottom of our pan is not heating uniformly there
are a variety of temperatures across the bottom of our pan. There are
several reasons for this. First, because of the various coil designs,
especially in less expensive induction hobs, there are hot spots where
the heat seems to concentrate at first. You witnessed this yourself
as you watched the water boil in your pan during the experiment. With
the real fancy and real expensive units there is a more even heating
across the bottom. With our units, it takes a little time for the
entire bottom to heat and the heat to reach the edges of the pan. The
meantime the hot spot is getting HOTTER AND HOTTER – the original
claim of the uneven heating on the bottom of a pan.
Secondly, to make it even more complicated, the bases (bottoms) of
some pans are not perfect. Actually the ferrous material required to
be in the bottom of our pans and pots, is not the best transmitter of
heat – although it retains heat quite well (example – cast iron.)
Aluminum does much better job of transmitting heat quickly, but it is
non-ferrous. An aluminum clad iron core pan might be our best bet,
but I don't have one so I can't test it. Also, some less expensive
induction ready pots and pans, don't permit they heat to radiate
We're not through yet. Thirdly, where is the temperature sensor
located? I would imagine, from the photos I've seen, that it is not
in the center of the unit and not anywhere where the wire coil is
located. In fact, it is outside the area of the wire coil looking at
the area at the edge of the pan (this depends upon the dimensions of
the wire coil the dimensions of the pan.) As it takes time for the
heat to reach the extremities of the pan for the thermostat to
recognize the temperature and start maintaining the correct
temperature, it is evident that parts of the pan will have exceeded
the desired temperature – Bummer again. [See the typical placement of
a small temperature sensing device in the previously mentioned
photograph. Notice that it is outside the area of the wire disk, and
realize that your pan or pot must be over the sensor for the
temperature control operation to work properly.]
This is one reason that your instructions may indicate never to use a
pan or pot that has under a certain dimension on your induction hob.
For example, with my hob the directions state not under 5 inches.
This of course leads me to think that the temperature sensor is
outside this 5 inch diameter circle. So I actually must be very
careful in making sure that the pan or pot I use has part of its edge
over the sensor. Boy it would be nice to know where that center was
Since the sensor is somewhere at the edge of the pan and perhaps the
heat is being developed from the center of the pan outward, it stands
to reason that it will take time for the heat to reach the edge of the
pan, especially if you are using cast-iron, and the center of the pan
will be extremely hot, probably higher than you want to be, until the
heat reaches the area at the edge of the pan that the sensor is
reading. Thus you can easily see that the actual temperature control
is not like you and I would prefer.
HOW INDUCTION COOKING WORKS - one of the good references on the
Internet. You may find this of valuable interest.
EXPERIMENT 2 – [Easy and quick to do]
This time, instead of using a temperature setting we are going to use
the full wattage capability of your induction hob. Again place a
quarter of an inch of water in a cold frying pan and turn your
induction hob on to full wattage – you are not using temperature
control at this time. As before, observe. See if the heating area,
with small bubbles forming, is the same size as the original. Perhaps
you may discover it covers a larger area. Watch until the entire
bottom of the pan is producing boiling water. Notice how the pattern
progressed. Comparison of Experiment 1 and Experiment 2 may produce
some results that you can utilize when cooking. I would imagine that
more expensive hobs heat the entire bottom much more quickly and
evenly – but that may not be entirely true.
EXPERIMENT 3 – [Requires an Infrared Thermometer (IR)]
Well temperature control for the liquidy mass is at lower temperatures
is pretty easy and may not be as critical, when we want to control the
temperature for deep fat frying, sauteing, grilling, etc., precise
temperature control may be more important. For example some oils will
smoke at a certain temperature. Some food items need to be prepared
at a medium temperature. We are warned that some cookware with Teflon
coating should not be exposed to heat about 400°. So we really want
our temperature sensing and control to be accurate.
This time we're going to take a pan without any water in it and use
our infrared thermometer to investigate the temperature of the inner
pan surface as we turn on our hob to maximum wattage. Probably, to
your surprise, you will find that the temperatures are all over the
digital display as you point your laser. Get to know what is
happening as the pan heats up. Try the same experiment with various
wattage settings. Again do the same with various temperature
settings. Remember, each time start with a cold pan. You can quickly
cool your pan under running cold water and then dry it.
You really don't need a ray gun type of infrared thermometer to do
this. A simple, small, less expensive hand-held infrared thermometer
will do the job. Small infrared thermometers are highly useful around
the house – especially in the kitchen. If you don't own one you might
consider one as a Christmas stocking stuffer. Google 'infrared
thermometers' either via web or images to check them out.
MY WORK AROUND TRICK
Okay, what can we do to help us with better temperature control short
of purchasing a whiz-bang unit at 6 to 15 times the cost of what we
What I do is similar to the experiments I mentioned above. If I want
to control the temperature I place the pan on the induction hob with
some water in it. I turned the hob on to a temperature setting of
150°. I wait until the entire bottom of the pan, from edge to edge,
has boiling water – AND THE WATER STOPS BOILING. This way I'm assured
that the temperature setting has been activated. I quickly dump the
water out and return the pan to the hob placing it back on before the
unit shuts itself off. Now I change the temperature setting, if
necessary, to what I desire. I believe that the temperature control
is now more accurate once it has initially started taking control.
You, of course, will have to experiment for yourself, but I do believe
you will be pleased with this technique.
I successfully use these techniques to keep, for example, soups and
other items warm at 150°, and keep Teflon coated pans from exceeding
that threshold of 400°.
I wrote something similar, in another place:
– If I have a, non-temperature sensitive mass in a pot that I would
just like to keep warm, I can easily place it on the hob, set the
temperature to 150°, and walk away. I really don't have to worry
about anything burning if the temperature over shoots a little, as a
liquid will take care of that, and the induction hob will eventually
settle down and keep the appropriate temperature of 150°.
– In the rare instance where the mass is temperature sensitive
(because of the chance of burning or coddling), that is, it shouldn't
be allowed to pass a certain temperature, I take alternate steps. I
will first put the pot containing only about a quarter of an inch of
water on the hob and set the desired temperature of 150°. I will wait
until the water stops boiling. This means that the thermostat has
kicked in. I will then empty the water from the pot and replace the
contents with the liquidly mass that I just want to keep warm. It is
best for this liquid is close to 150° to start with. I use either a
good digital thermometer one infrared thermometer to check the
temperature. This procedure will relatively sure that the vessel is
at the proper temperature and that the temperature sensor is working
before I add the liquidly mass (such as cream of pumpkin soup – which
I don't want to burn). As I said I rarely have to use this technique.
FEEL THE FORCE, YOUNG JEDI
Here is another little trick to be more aware of the temperature
sensor cycling on and off. On some units, you can actually hear a
slightly audible click as it cycles on and off. Another way, during
the cycling process, is to place your hand very gently on the pan or
pot handle. If you're sensitive enough, you can feel a slight
vibration when the unit is on which will disappear when the unit
cycles off. That way you will know that cycling is taking place.
Although it would be nice if there was some sort of indicator in the
digital area of the induction hob that would give you this
information. Mine doesn't have it.
Good luck with your induction hob cooking.
Re: INDUCTION HOB AND TEMPERATURE CONTROL
On Thu, 2 Dec 2010 06:57:18 -0800 (PST), zydecogary
<[email protected]> wrote:
>INDUCTION HOB AND TEMPERATURE CONTROL
Thanks -- lots of interesting information.
But if induction hobs were going to be that compliucated to use, I
BTW, I started with that same Wolfgang Puck unit. It's still as good
as anything, except that you can now get 1800 watt units for the same
Re: INDUCTION HOB AND TEMPERATURE CONTROL
On Dec 5, 3:57*pm, pltrg...@xhost.org wrote:
> On Thu, 2 Dec 2010 06:57:18 -0800 (PST), zydecogary
> <zydecog...@gmail.com> wrote:
> >INDUCTION HOB AND TEMPERATURE CONTROL
> Thanks -- lots of interesting information.
> But if induction hobs were going to be that compliucated to use, I
> wouldn't bother.
> BTW, I started with that same Wolfgang Puck unit. It's still as good
> as anything, except that you can now get 1800 watt units for the same
> -- Larry
I agree -- watching water boil is complicated and challenging. (Tee
The water experiments were just a demonstration for those who were
really unfamiliar with their units and were presented for them to
better see what was happening as the unit began to operate. In my
usage, I really have not had any problems with temperature control
that is not easily managed.
As you and I know, induction cooking is really simple -- in fact
easier than a normal stove top; be it gas or electric coil. You set
the power or the temperature (and a timer if you want) as you turn it
on and you have all the speed, safety and electricity saving available
Yes, I have seen the 1800 watt units, and for me, it might be
overkill. I rarely use the 1400 watts I have available now. I would
imagine if I were often using a very large stock pot I would sing a
different tune, But as I am generally cooking for one and use smaller
containers (except for my great big wok), I don't need the super
power, that is, unless I am missing something.
Other than more power for bigger pots, I do wonder what those $600 to
$1200 single hob units (not built ins) do that our $70 to $120 units
don't. I have read that some have a feature of auto-adjusting to the
size of the pot that is placed upon it (activating only that portion
of the copper coil that would really be used to excite the utensil.)
With the built in, there are lots of other features such as "place a
pot anywhere" and "automatic adjustment to shape of pot, pan or large
griddle under-surface", features that I can admire, but that I don't
It is also interesting to watch the cooking channel and the food
network and discover the increased use of induction hobs that is
creeping in -- especially in the shows that visit restaurant kitchens.
Not too much is made of the fact that induction cooking is going on,
probably because most of America is in the dark about induction
cooking and wouldn't know what they are talking about on the show.
Europe and Asia have taken the lead on this one. Talk about being
The same with Sous-vide cooking. Most would say "What ?????????" Yet
some of the finest restaurants (and even the not so 'finest') use Sous-
vide for some of their food preparation. This evening I prepared some
chicken using the Sous-vide method. I am experimenting with that too.
Next I will use it for various fish.
Ain't cooking FUN! Tomorrow -- Shabu-Shabu.