Cast iron and powersettings on induction cooktop.

[HappyamateurDK]

Hi all.

As mentioned in earlier threads, I really enjoy using cast iron cookware.

Most cast iron cookware makers make sure to point out that you should never go above half power when using cast iron. That is to prevent warping or cracking.

This brings me to the problem. On my electrolux/Foss induction cooktop, half power is not nearly enough to fry most stuff.

It goes from 1-14 + a boost setting.

I usually have to go to 9 or 10 the get the pan hot enough.

Maybe the power settings in my Induction cooktop isn’t linear?

How high do you guys usually crank your cooktops when using cast iron?

Have a nice day.
Søren

 

[Michi]

I wouldn’t worry about it. Just set the heat to what works for what you want to cook and don’t worry about the numbers on the dial.

The one thing you might want to do is to heat up the pan in two stages, so you don’t create stress from uneven expansion. That’s probably the most effective way to make your pan last.

Cast iron is famous for being damn near indestructible. It survives camp fires and the like, so just cook away and enjoy your pan.

 

[sumis]

yup, what @Michi said. just go halfway first and then increase heat from there. good practice for most pans.

.

 

[Taurahe]

Keep in mind, the cast iron itself plays a huge role in how it will heat on induction. Induction cooks through using a magnetic field. The ability for cast iron to heat up will depend on how magnetic it is to begin with , which will vary great due to metallurgical composition.

In general , I have to disagree with the above statements. Cranking the heat could be an invitation for disaster . Cast iron can be sensitive to thermal shock. Induction heats a pan so quickly, you risk cracking the pan because of this. Don't wait until the last minute.... Take your time and start at a lower setting ... Like 3. Let it heat up , use water to see how hot the pan is. Give it some more as needed until you get the temp you desire.

 

[simona]

Keep in mind, the cast iron itself plays a huge role in how it will heat on induction. Induction cooks through using a magnetic field. The ability for cast iron to heat up will depend on how magnetic it is to begin with , which will vary great due to metallurgical composition.

In general , I have to disagree with the above statements. Cranking the heat could be an invitation for disaster . Cast iron can be sensitive to thermal shock. Induction heats a pan so quickly, you risk cracking the pan because of this. Don't wait until the last minute.... Take your time and start at a lower setting ... Like 3. Let it heat up , use water to see how hot the pan is. Give it some more as needed until you get the temp you desire.

Low and slow is good.

 

[Jovidah]

The main thing to be worried about is thermal shock (especially on enamelled stuff ; can lead to cracking) and uneven heat.
Just give it some time to warm up and even out the heat and then you can go higher.

It's sometimes recommended to preheat them in the oven, which does work, but unless you're also planning to use that oven to cook it's incredibly inefficient when it comes to energy consumption.

Keep in mind, the cast iron itself plays a huge role in how it will heat on induction. Induction cooks through using a magnetic field. The ability for cast iron to heat up will depend on how magnetic it is to begin with , which will vary great due to metallurgical composition.

In general , I have to disagree with the above statements. Cranking the heat could be an invitation for disaster . Cast iron can be sensitive to thermal shock. Induction heats a pan so quickly, you risk cracking the pan because of this. Don't wait until the last minute.... Take your time and start at a lower setting ... Like 3. Let it heat up , use water to see how hot the pan is. Give it some more as needed until you get the temp you desire.

Cast iron is cast iron, it's pretty much always just pure iron with a few % of carbon thrown in (can't remember if it was 2 or 3). Yes it's magnetic as hell and yes they will work just fine. It's not like someone's out there making 'cast iron pans' that are like 25% chromium.

Cranking up the heat is what you can do after you put in the ingredients to avoid the pan cooling down. But I agree with the 'heat it up slowly' recommendation...and on enamelled stuff, probably not empty either (go in with some oil or butter or something).

BTW heat up slowly kinda counts for everything; Demeyere also recommends against using boost function or heating stuff up at your highest setting.

 

[Taurahe]

I have to disagree...... Not all cast iron is the same. My lodge , LC , tranontina and other cast iron pieces heat up just fine on my induction burner .... However, I have a China made pan that does t heat up for squat on induction. Magnets barely stuck to it. I gave it away to a friend who wanted it. This is the same reason some induction ready pans work great , and some are garbage.... Quality of the metal overall

 

[Jovidah]

That's just downright weird; iron is cheap enough that there's no good reason to substitute it for anything else. Are you sure it wasn't cast aluminium?
It's not like you require 'high quality iron' to make a proper cast iron pan; even in the Lodge factory there's a lot of scrap metal involved.
Cheap thin 'induction ready pans' not working is really a different thing. That's because they're just slapping some tiny magnetic wafer on aluminium pans that otherwise wouldn't work.

 

[HappyamateurDK]

I have to disagree...... Not all cast iron is the same. My lodge , LC , tranontina and other cast iron pieces heat up just fine on my induction burner .... However, I have a China made pan that does t heat up for squat on induction. Magnets barely stuck to it. I gave it away to a friend who wanted it. This is the same reason some induction ready pans work great , and some are garbage.... Quality of the metal overall

My guess would be that the supposed to be cast iron cookware was not really cast iron. It wouldn't be the first time cheap Chinese manufacturer have a too pragmatic relationship to the truth.

 

[Michi]

Cast iron is essentially all iron, with minor impurities of carbon. If you have a “cast iron” pan that isn’t magnetic, it contains no iron, period.

All cast iron pans are suitable for induction. If they don’t work on induction, they aren’t cast iron. That’s just physics. No room for argument or interpretation there.

 

[mengwong]

I’m just wondering at the economics – what substitute for cast iron could possibly be cheaper than actual iron? On this or any other nearby planet.

https://allthatsinteresting.com/why-are-barns-painted-red

 

[Dan-]

Melamine? Industrial waste? Pot metal?

 

[Michi]

I’m just wondering at the economics – what substitute for cast iron could possibly be cheaper than actual iron? On this or any other nearby planet.

Recycled aluminium that is contaminated with other metals. It's easier to deal with during manufacture (lower temperatures—660 ºC vs 1,530 ºC), can be die-cast into any shape, and considerably cheaper than cast iron. Just compare the price of an aluminium tortilla press with a cast iron tortilla press. The difference is up to a factor of two.

 

[Jovidah]

The sad thing is that cast aluminium actually makes for super awesome pans. The problem is they're almost invariably coated with garbage non-stick coatings, and they just won't work on induction.

Although the latter isn't easy to fix (just slapping on some magnetic plate always leads to crap results, and making a fancy sandwich a la Demeyere would drive up cost and complexity), I've always wondered why I've so far never really seen an enamelled cast aluminium pan. My best wild guess is that the thermal expansion properties of the aluminium might be a problem leading to cracked enamel?

 

[stringer]

The sad thing is that cast aluminium actually makes for super awesome pans. The problem is they're almost invariably coated with garbage non-stick coatings, and they just won't work on induction.

Although the latter isn't easy to fix (just slapping on some magnetic plate always leads to crap results, and making a fancy sandwich a la Demeyere would drive up cost and complexity), I've always wondered why I've so far never really seen an enamelled cast aluminium pan. My best wild guess is that the thermal expansion properties of the aluminium might be a problem leading to cracked enamel?

It's actually pretty common. Although I've never tried using any of it.

https://www.webstaurantstore.com/55397/cast-aluminum-cookware.html

 

[Jovidah]

It's actually pretty common. Although I've never tried using any of it.

https://www.webstaurantstore.com/55397/cast-aluminum-cookware.html

Wow talk about Staub ripoffs.
I was actually never able to find anything like that here. And I have actually looked for it.
Surprising I've never heard of them before; even if it's a US only thing you'd expect someone like ATK or Serious Eats to pick up on it. Lower weight is really a massive benefit for many people, and probably the most mentioned drawback of the cast iron stuff.

 

[woyuskinny]

Cast iron is essentially all iron, with minor impurities of carbon. If you have a “cast iron” pan that isn’t magnetic, it contains no iron, period.

All cast iron pans are suitable for induction. If they don’t work on induction, they aren’t cast iron. That’s just physics. No room for argument or interpretation there.

Cast iron has more carbon than steel, with some fraction of Si too usually. The magnetic properties of iron alloys are not necessarily a function of iron content, but the xtal structure the iron. Ferrite(body cubic): ferromagnetic, Austenite(face cubic): not ferromagnetic. 304 alloy is mostly iron, and isn't ferromagnetic. I'm not a cast iron expert, so I don't know what magnetic changes might result from impurities that alter the relative components and quantities in other dominant phases/xtal structures in cast iron, such as cementite (Fe3C) or graphite (C). I'm guessing too that the 'cast iron' pan that works poorly/not at all on induction is not typical grey cast iron, but that doesn't mean it doesn't contain a significant fraction of iron. Of course, it could be Al, but wouldn't that be really obvious when picking it up?

 

[Helicon]

The problem is they're almost invariably coated with garbage non-stick coatings, and they just won't work on induction.

Well, that's not entirely true. Woll and Swiss Diamond both make outstanding induction-capable cast aluminum cookware with quite durable nonstick coatings. I prefer Woll to Swiss Diamond, but both are worth a look. After all, the only thing necessary to make a pan induction-capable is for a ferritic disc to be affixed to the bottom, and the nonstick coating is there mostly because people are paranoid about cooking in bare aluminum.

 

[Nemo]

How is rough cast iron on the glass cooktop? Does it scratch the glass?

 

[stringer]

Well, that's not entirely true. Woll and Swiss Diamond both make outstanding induction-capable cast aluminum cookware with quite durable nonstick coatings. I prefer Woll to Swiss Diamond, but both are worth a look. After all, the only thing necessary to make a pan induction-capable is for a ferritic disc to be affixed to the bottom, and the nonstick coating is there mostly because people are paranoid about cooking in bare aluminum.

I am far more paranoid about cooking off of nonstick nonsense than bare aluminum. I have never even heard of that. Just curious, why would people be concerned with cooking on bare aluminum? Like it's harder to cook with, or it's somehow dangerous? I have mostly worked in large scale commercial operations that cook most everything on bare aluminum.

How is rough cast iron on the glass cooktop? Does it scratch the glass?

Guilty

 

[Nemo]

Ouch!

 

[Helicon]

I am far more paranoid about cooking off of nonstick nonsense than bare aluminum. I have never even heard of that. Just curious, why would people be concerned with cooking on bare aluminum? Like it's harder to cook with, or it's somehow dangerous?

I'm not saying it's supported by the current research, but there are seemingly plenty of people who still believe that aluminum is somehow linked to Alzheimer's or contributes to the development of amyloid plaques in the brain. Certainly that was the case on the Chowhound cookware boards. Of course, there was also a handful of people there who were hugely concerned about the leaching of chromium and nickel from stainless steel into long-cooked acidic dishes. They swore they'd only ever cook in enamel-lined cast iron and tin-lined copper. It was pretty hardcore.

I use induction at home and have acquired a decent selection of bare aluminum cookware, mostly from Ballarini and Agnelli, that performs incredibly well and is also quite inexpensive. I really cannot understand why more people don't do the same!

 

[Jovidah]

Yeah the anti-bare aluminium thing is basically the anti-vax of cookware; it's based on very little evidence. I think what is more relevant for consumers is that I vaguely recall aluminium being reactive?
Was never overly impressed with those induction-disks under aluminium pans. Yeah they'll work.... somewhat... but it never gave me the same performance you get from a proper stainless or cast iron pan.
The nonstick on pans like Woll or Swiss diamond is still just teflon-based. Yeah it might be a fancier composition or better adherence or more layers, but in the end it's still a pan with a limited lifespan. That's just a fact of life with all of them, regardless of brand. The only thing that truly lasts on them is the environmental impact.

 

[Helicon]

In my experience the Woll coatings do actually last longer. Some of them are claimed to contain things like industrial diamonds or titanium for abrasion resistance, but in a home setting this is mostly marketing puffery. As long as you don't use metal utensils or crazy high heat they'll last plenty long. Certainly longer than on an average nonstick pan bought at a cookware supply shop.

The ferritic discs on the bottom of induction-capable cookware are just fine. I mean, how do you think the stainless clad pans work? They have a ferritic layer at the bottom that adheres to the adjacent layer of more conductive, non-ferritic material – usually aluminum or copper. I've never had a problem with any of them, as long as the adjacent material is relatively conductive and strong/thick enough to inhibit warpage... which is actually something I've experienced many times with thinner clad pans.

Cast iron just doesn't heat evenly at all on my induction cooktops. I have to preheat it in the oven if I want to use it to sear anything, and that's just such a hassle I tend to avoid the stuff now in favor of other materials.

And yes, aluminum is reactive - to an extent. But in the presence of air and water it forms a pretty durable (but thin) oxide layer. Some foods should never be cooked in bare aluminum, however – rhubarb, for example.

 

[Michi]

How is rough cast iron on the glass cooktop? Does it scratch the glass?

I have not had any issues with my 12" Lodge. The bottom isn't perfectly polished, but still quite smooth. Definitely no scratches.

The one thing to keep in mind is to lower the pan slowly onto the cooking surface, otherwise you might crack the glass. But it would take a seriously hard bang to have that happen; those Ceran cooktops are tough.

 

[Michi]

Cast iron has more carbon than steel, with some fraction of Si too usually. The magnetic properties of iron alloys are not necessarily a function of iron content, but the xtal structure the iron. Ferrite(body cubic): ferromagnetic, Austenite(face cubic): not ferromagnetic. 304 alloy is mostly iron, and isn't ferromagnetic. I'm not a cast iron expert, so I don't know what magnetic changes might result from impurities that alter the relative components and quantities in other dominant phases/xtal structures in cast iron, such as cementite (Fe3C) or graphite (C). I'm guessing too that the 'cast iron' pan that works poorly/not at all on induction is not typical grey cast iron, but that doesn't mean it doesn't contain a significant fraction of iron. Of course, it could be Al, but wouldn't that be really obvious when picking it up?

What makes stainless steel non-magnetic is indeed austenite. And that is created by the high chromium content (≥ 16%) of stainless steel. Cast iron is just iron and carbon (with maybe some other minor impurities), so it stays magnetic.

I can't think of any realistic scenario why "cast iron" would be non-magnetic, other than containing a lot of aluminium. Fe-Al alloy becomes non-magnetic once the aluminium content reaches 33%.

I strongly suspect that any non-magnetic "cast iron" pan is non-magnetic for cost reasons. The pan manufacturer can buy an alloy that is mostly aluminium plus other metals much more cheaply than iron because a mixed impure alloy does not require the recycler to carefully separate out the different metals. Instead, the recycler can just sell whatever bunch of left-over bits they have at the time and say "x% aluminium plus assorted other metals".

 

[Michi]

I think what is more relevant for consumers is that I vaguely recall aluminium being reactive?

When I was a student and poor as a church mouse, the only cookware I could afford was aluminium pans and pots from K-Mart. They were OK, but I do remember learning quite quickly that long-simmered marinara sauce wasn't that great. Not that I couldn't eat it, but it did have a metallic tang to it.

 

[btbyrd]

Cast iron just doesn't heat evenly at all on my induction cooktops. I have to preheat it in the oven if I want to use it to sear anything, and that's just such a hassle I tend to avoid the stuff now in favor of other materials.

This summarizes my view as well. Cast iron is a terrible conductor of heat and induction heating is inherently uneven. The material and the heating method both bring out the worst in each other. I don't use cast iron induction except for a small-ish dutch oven that I use for deep frying. I just sort of heat it gently and once it's come up past 275 or 300, I just crank it and all bets are off. I don't care about warping on that pot, but I care enough about it on my cast iron and carbon steel pans to avoid induction in most instances.

 

[jamiewakeham]

Maybe the power settings in my Induction cooktop isn’t linear?

Just to pick up on this point: my Bosch definitely isn't linear. It has 1-9 and boost. You'd expect 9 to be 90% power, 8 to be 80%...

Testing both with a power meter and by timing water heating up, 9 is about 60% of boost. 7 is about 25%. Everything below that is just fine gradations. It actually makes sense; it allows fine control of a simmer, whereas when I want boost I just want all the power. But it took me a while to get used to it!

 

[Dan-]

That makes sense for Bosch induction though since the linked element turns off when you use boost.