| Tim May |
This post is mostly about my measurements (Christopher Kimball-style)
of wattages and heating times with my new Sunpentown induction cooktop,
as compared to an electric hotplate and a butane burner. And my
experiences with a cast iron wok (!), the Lodge 14-inch monster.
(Modern thin woks are sometimes called "carbon steel," sometimes
"iron," when what they are is mostly cold rolled steel, or hammered
steel sheet. Mostly iron, to be sure, but really non-stainless steel. A
cast iron wok is the stuff that Griswold, Wagner, and Lodge cookware is
made of. Altogether different. And unusual for a wok. More on this
later.)
In article <42528c48.4948796@news.individual.net>, AlleyGator
<AlleyGator@otheryellermeat.org> wrote:
> Tim May <timcmay@removethis.got.net> wrote:
>
>
> >(I cook simply, but often using a PC. Some potatoes and a few pieces of
> >Aaron's chicken, from TJ's, cook in under 20 minutes, from a cold
> >start, in my Kuhn-Rikon PC. I use an induction cooktop, an inexpensive
> >Sunpentown (? don't blame me for the weird name) "Mr. Induction" that I
> >got for $125. Almost as fast as gas, but much more convenient. The
> >ferromagnetic bottom of a Kuhn-Rikon is perfect. American PCs tend to
> >be aluminum (Presto, Rival, etc.), so they won't work on an induction
> >cooktop.)
>
> Tim, just curious about the current draw for that induction unit.
> Just did a quick search and didn't find a lot of detail. I assume
> it's no worse than an electric skillet or whatever? (BTW, yes we do
> know each other <G>) I've been wanting one for the wok, since it's
> either electric or an outside propane burner here. Sheldon
> recommended a good one but it's several hundred bucks. Ever try yours
> with a wok?
Wow, a question I am very well-prepared to answer. I did a bunch of
tests of current draw (actually, watts, but watts = amps times volts)
on this induction unit when it arrived. I also measured the time to
raise a liter of water from tap water temperature (about 50 F in my
area, this time of year) to the first (7-8 psig) and second (14-16
psig) rings on my 5 liter Kuhn-Rikon.
Here are my recordings, taken with a Brand Electronics watt-meter
(where one plugs the Brand into the wall, then plugs the appliance into
the Brand, zeroes it, and begins):
Sunpentown "Mr. Induction," set on highest setting:
1st ring: 8.75 minutes
2nd ring: 9.5 minutes
measured watts: 1170
measured KWH to 2nd ring: 0.19
Aroma electric coil (standalone hotplate, comparable to medium-sized
coil on electric range), set on highest setting:
1st ring: 16-17 minutes
2nd ring: 17.5-18 minutes
measured watts: 760
measured KWH to 2nd ring: 0.23
Butane burner, Max Burton, set on highest flame:
1st ring: 6.5 minutes
2nd ring: 7 minutes
measured watts: not available (though I could have weighed the butane
cannister before and after and imputed a BTU value, I didn't)
KWH to 2nd ring: not available (ditto)
I have an outdoor wok burner (like a turkey fryer burner, except even
larger) which heats my woks to cherry red in a couple of minutes. (See
the Alton Brown "Good Eats" episode called "Squid Pro Quo" to see a
turkey fryer heat a wok to cherry red in minutes.) But I haven't done
the above tests with it...partly I don't want to melt or damage the
resin handles on my Kuhn-Rikons with such an intense heat source.
With the butane burner above--which I use indoors, as it is fairly safe
to do so, and units like this are used by professional chefs
indoors--there was a fair amount of heat "wasted" by going up the sides
of the pot. This was apparent just by waving my hands around the pot.
As for your question about using a wok, a couple of points:
1. For very fast, modern-style wok cooking, I use a large (17-inch)
rolled-steel wok on the aforementioned outdoor burner.
2. But sometimes I don't feel like stepping outside onto my deck, so I
use woks inside. Not the full "wok he" ("spirit of the wok"), but often
good enough, especially for improvised stir fries.
For this, the induction cooktop is not so great. A round-bottom wok
will still make "inductive contact" (that is, the "no contact" beeper
does NOT go off), but I surmise that the contact is not so great. I
haven't done enough experiments. Instead, I have either used an older
flat-bottom wok, also rolled-steel, or my newer Lodge cast iron wok.
3. The idea of using a cast iron wok is seemingly counter to everything
said about woks for "fast" cooking. However, Googling around, and
thinking about the issue, I realized that thin, steel woks on weak heat
sources (indoor gas burners or electric coils) had the "gloppy" problem
so often seen: the thermal mass of stuff thrown into the wok overwhelms
the thermal mass of the part of the wok doing the cooking, and the heat
source can't keep up. And so the same reason that a cast iron or heavy
pan is so good for searing steaks and whatnot is the same reason it
works better as an indoor wok: once very hot, as hot as the indoor
burner or coil or induction unit can make it, it _STAYS HOT LONGER_
when things are put in the pan.
Which is why people have managed to do stir fires in conventional
skillets (recall stories of immigrants from China making do with
western appliances).
Anyway, Googling around, I discovered that Lodge made a couple of cast
iron woks, sort of like their big cast iron skillets, but wok-shaped
inside and with a flat bottom (accomplished in the obvious way by
molding the wok with a large chunk of iron extending out on the bottom,
flat on the bottom). They seem to have discontinued one of the models,
the one with a long, insulated handle, in favor of a simpler model with
just two small handles on the sides. This makes sense, as I doubt
anyone would try the "wok flip" with such a heavy wok.
I found mine for $43 from Amazon. Listed as a "14-inch cast iron wok."
Free shipping, no sales tax, etc. No lid, by the way, though one could
make do with a lid from a Lodge fry pan (or even an aluminum lid of
some sort), for steaming.
It works quite well, for more than just stir fries. Basically, it's a
large, heavy skillet with a wok shape. The "sweet spot" of highest heat
is in the center, of course, because of heat losses up the sides. This
is how the searing can be done at the bottom, then ingredients pushed
up out of the center, in the usual wok style.
Cleaning is the same as with the rolled steel woks: hot water, a stiff
brush or nylon scrubbing thing, just to get the worst of the gunk out,
then drying either on the cooktop or whatever. (I usually put it back
on the induction cooktop, hit the "HI" button until it's hot again, and
wipe it down with a small amount of vegetable oil, to aid in
preservation and seasoning.)
Lastly, you mentioned the more expensive induction cooktops. Indeed, I
have seen them listed in restaurant supply prices at $500 and up.
Presumably more wattage.
The unit I got is really just like a single induction surface from one
of those GE or similar induction ranges that were sold up until
recently. (I don't know why they were discontinued....I heard something
on the Net recently about Viking planning to introduce a new induction
range.)
The "Sunpentown" model I got only weighs a few pounds. Apparently these
are quite popular in Asia. As for durability, it looks well-made. No
stainless steel, no big fans, just a small, counter-top unit. Sort of
the analog to consumer-grade microwave ovens. (Except of course, unlike
microwave ovens, well-suited for a variety of conventional frying,
wokking, and pressure cooker uses.)
I hope this helps. I would buy another Sunpentown in a second, if I
needed a second cooktop. (I intended to run propane into my kitchen, to
replace my aging and dangerous electric range. Then I discovered how
expensive the "permits" might be, so I have procrastinated on this.
Hence my purchase of a small electric hotplate and then the induction
cooktop. And now I am thinking I may never bother to get the propane
line run at all.)
--Tim May
--
Uo
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| AlleyGator |
Tim May <timcmay@removethis.got.net> wrote:
>>Sheldon recommended a good one but it's several hundred bucks. Ever try yours
>> with a wok?
>
>Wow, a question I am very well-prepared to answer. I did a bunch of
>tests of current draw (actually, watts, but watts = amps times volts)
>on this induction unit when it arrived. I also measured the time to
>raise a liter of water from tap water temperature (about 50 F in my
>area, this time of year) to the first (7-8 psig) and second (14-16
>psig) rings on my 5 liter Kuhn-Rikon.
Wow. Thanks for all the information. I did forget to mention that
the expensive unit Sheldon found was specifically for wok use. Now I
have more to think about.
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| Tim May |
In article <4252f28c.27535781@news.individual.net>, AlleyGator
<AlleyGator@otheryellermeat.org> wrote:
> Tim May <timcmay@removethis.got.net> wrote:
>
> >>Sheldon recommended a good one but it's several hundred bucks. Ever try
> >>yours
> >> with a wok?
> >
> >Wow, a question I am very well-prepared to answer. I did a bunch of
> >tests of current draw (actually, watts, but watts = amps times volts)
> >on this induction unit when it arrived. I also measured the time to
> >raise a liter of water from tap water temperature (about 50 F in my
> >area, this time of year) to the first (7-8 psig) and second (14-16
> >psig) rings on my 5 liter Kuhn-Rikon.
>
> Wow. Thanks for all the information. I did forget to mention that
> the expensive unit Sheldon found was specifically for wok use. Now I
> have more to think about.
I wasn't closely following it at the time, but I recall seeing a bunch
of induction cooktops used on some of the "Food Network" shows (and
something about their not having easy access to gas, what with fire
codes and all--apparently the small butane cooktops are fine to use in
most places, but bringing in large (e.g., 20-lb) bottles of propane
into office buildings and other such places is a no-no.
(When I was a kid in France, we had "bottled gas" under the sink,
presumably more or less equivalent to today's propane grill-type
cylinders, but this is now frowned upon. Not because of burning propane
or butane indoors being ipso facto deadly, but because of the
implications of loose fittings, improperly-mated connectors, and leaks
in general. Also, the larger propane refillable tanks are apparently
designed to send the nozzle head "straight up" in a fire. OK then for
outdoor use, not so OK in a kitchen. Anyway, I recall that the various
Food Network shows had to use induction cooktops...at least for a
while, as I think Emeril and that crew cook over gas.)
Kimball's "Cook's Bible," I think is where I saw it, mentions that most
commercial Chinese places use gas, understandably. Very fast heating
time, large amounts of BTUs/hour, and the cost of installing gas can be
amortized over many burners.
To try the induction/cast iron wok method, try an ordinary cast iron
skillet on a standard cooktop. (If you don't have a Lodge skillet, a
nice 12-inch model can be had very inexpensively.). Let it get good and
hot, as for searing steaks or chops. Then try it as a wok. Not as
convenient as a bowl shape, but you'll see how combining ingredients
can be altered a bit to deal with the thermodynamics of this setup
(where the thermal mass helps keep the temperature high, not "drooping"
as with a thin steel wok on an electrical or indoor gas range).
It should (based on my experiences, especially with my cast iron wok)
at least eliminate the bane of my indoor wokking: gloppy, stewed or
braised vegetables and non-seared meat.
Personally, I wouldn't pay big bucks for a special wok-only induction
cooktop...I would either cook outside on my "blast furnace" wok burner
(supposedly 120,000 BTU/hour) or indoors on a butane burner, if not on
the consumer-grade induction cooktop.
BTW, I haven't measured the temperature the induction cooker gets to.
It nominally turns off (cycles) at "425 F." I have no idea how it
"knows" what temperature it is at, though conceivably it measures
something regarding current draw, a possible measure of ferromagnetic
interaction. More likely, not.
I do not that bits of paper towel don't spontaneously ignite in the wok
or skillet, whereas they do when I use my blast furnace. (Thus,
anecdotally, above 451 F.)
If I had one of those Alton Brown "IR gun" sensors, I could measure the
temperature. Or I could put some oil in, enough to cover the tip (and
then some)of my meat thermometer, though I'm not sure how accurate it
woud be at these high temperatures.
One last thing about induction cooktops is a reminder that they only
work with ferromagnetic pots and pans: if a magnet sticks to them, they
are OK to use. Which rules out some materials: aluminum, most
importantly, and even some stainless steels (e.g., some with aluminum
cores and a thin cladding). My Calphalons pans won't work. Those
strange Corning glass pots and pans obviously won't work.
Use a refrigerator magnet on the bottoms of pots and pans to see which
will work. Take one to a kitchen store, or borrow one, to check on any
pots and pans being considered.
As I mentioned in the earlier post, round bottom woks _will_ make
"inductive contact," in that the warning beep doesn't go off, but the
field falls off with distance (I could do some experiments with lifting
the pots to see the range, but haven't yet), so a round bottom is not
ideal for an induction cooktop. The usual aluminum wok ring used to
stablize a round-bottom wok on a flat surface should not interfere in
any way.
All of my "Meyer" (a cheapie Costco brand, apparently the maker as well
of some "name" brands) pots work, as do, of course, my Lodge pans and
Dutch ovens and such.
--Tim May
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| Aaron Bergman |
In article <050420051203105577%timcmay@removethis.got.net>,
Tim May <timcmay@removethis.got.net> wrote:
> Anyway, Googling around, I discovered that Lodge made a couple of cast
> iron woks, sort of like their big cast iron skillets, but wok-shaped
> inside and with a flat bottom (accomplished in the obvious way by
> molding the wok with a large chunk of iron extending out on the bottom,
> flat on the bottom).
I have one by Bodun which I quite like. Big and heavy, but if you let it
sit on the burner for a while, it definitely heats up.
Aaron
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