What is the purpose of using potato peels for seasoning a cast iron pan?

Question

My first ever cast iron pan just arrived. The package contains following seasoning directions.

1. Wash with clothes detergent (not soap or dish detergent) to remove the rust protection coating.
2. Wash thoroughly with warm water to remove detergent. Dry pan.
3. Fill the pan with fresh potato peels. Pour sunflower oil or rape oil on them, until it is almost full with oil.
4. Leave the pan with the potato peels and oil for an hour on the next-to-highest setting on the stove top.
5. Throw away the potato peels and oil, dry the pan with kitchen paper
6. Coat the pan with a thin layer of sunflower or rape oil.

Not only don't I want to spend the afternoon peeling potatoes and then throw away most of them (I cannot eat the amount of potatoes needed for these peels), but even the positive amazon reviews for the pan all warn before the stench the charring peels produce during the seasoning: It lingered for about three days although I changed the fume hood filters, but it is a small price to pay for such a great pan. For me, it is a big price, because I have no fume hood, and there is no door between the kitchenette and the living room/bedroom. I looked up advise on seasoning pans, hoping for some trick, and found this question where the accepted answer doesn't include potato peels (in fact, no answer mentions them).

Now I am unsure whether to use them. On the one hand, I don't want to deal with the side effects. On the other hand, a producer is supposed to know what is best for his products. I don't want to get poisoned by an anti-rust coating residue that would have been rendered harmless in a chemical reaction with potato peels. Besides, I can't use the seasoning process outlined in the question I linked, because my pan doesn't fit in my oven.

I guess it would be easier to decide if I knew of their purpose. Does any of you know of using potato peels for seasoning pans, and can you tell me why they are needed? Or is it just an urban legend the ignorant manufacturer printed in the manual (the pan is not a well-known brand, maybe some hardware manufacturer decided it will be easy to add pans to their product line and made them without gathering enough know-how).

Asked by rumtscho

Answer

I personally had never heard of it, but after doing some research online, I found another set of instructions that called for boiling potatoes in the pan before seasoning:

After boiling potato peelings for 15 minutes, the skillet had a nasty slurry of grey looking sand in the bottom Once the skillet was heated, the pores were opened, and the starchy/water mixture was able to draw out oils and dirt that I was not capable of getting to through normal washing. I fully do not understand the science behind why the starch/water mixture did this, but the experience was enough to convince me of the need to do this. So much in fact, that I did this process twice on each skillet.

I read a few too many web pages while researching this, and didn't save all of the links, but I did notice a few things:

1. Some of the posts kept switching between saying cast iron and carbon steel; both are typically seasoned, but they're different materials, so I don't know if it's recommended for both, or if people were mixing things up. (I only have one carbon steel item, a wok, which I got second hand, so had already had its first seasoning).

2. Some of the posts mentioned boiling potatoes for 15 minutes, other mentioned frying potatoes as the first thing to be cooked in the pan (in oil), some mentioned cooking them 'til they burn. The boiling potatoes ones also mentioned it works for cleaning stainless steel pans.

3. Some mentioned peels specifically, others say that you can use any part of the potato ... if it's the starch that's of interest, I'd think the middle would actually be better, but I'm guessing that the peels were considered waste, and so considered a less valuable item; I'd be inclined to just use one potato, dispatched with a peeler, if you were trying to avoid wasting potatoes you weren't going to eat.

Answered by Joe

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Repairing the Seasoning on a Cast Iron Pan

Question

I had some caked, hard burned substance (garlic, really, from steak) on my cast-iron pan. I tried cleaning it with a brush, and it didn't come off.

So unfortunately, I put a bit of muscle into it, and now the bottom of my cat-iron pan has bits that are positively shiny and silvery. I'm pretty sure the seasoning came off here and there.

Is there a way to fix it, other than completely re-stripping the seasoning and re-seasoning it from scratch?

Asked by ashes999

Answer

So, just answering the new part of the question:

You can simply season "over the top" of the existing seasoning. To do this, you'd go through the normal seasoning process, wiping the pan with oil, heating in a 500F oven, wiping again, heating again. This will fill in the "holes" in your seasoning and you'll be able to use the pan again.

However, you will also end up with somewhat rough, uneven seasoning on the bottom. This will make things more likely to stick than if you completely reseasoned the pan. You can improve this by scrubbing the bottom of the pan with a mixture of course salt and oil. This will "sand down" the seasoning without completely removing it.

You should also ask yourself if maybe the original seasoning of the pan wasn't faulty, given that some of it already scrubbed off.

Answered by FuzzyChef

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Is it normal that I keep burning my seasoning off my cast iron?

Question

I use cast iron, a lot. But I've got a problem, whenever I do something that requires high heat or really anything over medium (which is somewhere around 450-500F on my stove according to my IR thermometer), the seasoning burns off my pan! There's smoke and all that and then by the end of the cooking, large parts (mostly in the middle outward where its hottest) of the pan don't have any seasoning left and I can see the bare cast iron. Above 600-700F, I definitely expect it but it happens just above/around 500F for me.

Am I doing something wrong? Is this normal? Is there a way to season the pan that keeps this from happening? I've just been using canola oil.

Asked by rfusca

Answer

No, this isn't normal. A little flaking, perhaps, when you go over 600°F, but 500°F shouldn't do anything. It shouldn't even smoke.

Something is wrong with the seasoning on your pan. From the fact that its smoking, I'd guess its not sufficiently baked on. Alternatively, maybe the pan wasn't clean when you applied it.

If its just not baked on, I'd remove all the flaking bits (with some harsh scrubbing, sand paper even), clean it thoroughly, then bring it to around 300°F (stovetop or oven). This will make sure it is completely dry. Spread a thin layer of high-iodine value oil (flax seed is great, soy is pretty good and cheap and easy to find: look for the bottle that just says vegetable oil and check the ingredients, it's probably soy). Spreading is easy with a paper towel.

Next, toss into a very hot oven, 400–500, smoking is expected. Bake for 90 minutes, then turn the oven off. Allow pan to cool with oven. Once its cool, touch it. If its at all tacky, put it back in the oven, and bake for another hour (once again, allowing to cool with oven). It should be a shiny black at this point, and not at all tacky.

You can repeat the process to add more layers. Two should be reasonably non-stick to start cooking on.

If it still peels off after this, you're probably going to need to strip the seasoning and re-season the pan, after stripping it to bare metal. See What's the best way to season a cast iron skillet? to season it from bare metal.

Answered by derobert

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What causes sticking and what can I do to reduce food sticking to my cast-iron skillet?

Question

I enjoy using my cast-iron skillet, but how can I minimize the amount of food that sticks to it while cooking? I apply oil after cleaning, and for the most part, I only clean it with hot water and a rag.

For the most part, breads (pancakes, sandwiches) and meats do fine, but I have particular trouble with potatoes and fried eggs.

What causes sticking and what can I do to minimize the it?

Asked by Abe

Answer

The first rule to keeping food from sticking to cast-iron is to keep it well primed - it sounds like you're doing that already. Beyond that, read these tips for cooking with stainless steel - they'll also apply to cast iron.

To summarize:

• Food sticks when chemical bonds form between the food molecules and the metal.
• Very hot oil helps to reduce sticking by instantly and continuously heating the food until it's surrounded by a layer of steam from its natural moisture content boiling. Let the oil get nice and hot before adding food.
• Very hot oil also binds with the pan, so food can't. This is the principle behind priming the pan in the first place.

I have some theories regarding particular problem foods:

• Most of the molecular bonding occurs from proteins. Egg whites are mostly protein.
• Frying potatoes creates surfactants in the oil, which cause oil and water to mix. This reduces the effect of the protective layer of steam. (Some people save and re-use cooking oil -- though it can impart a delicious flavor to later meals, it will also build up surfactants if the same oil is used too many times.)
• Also, keep in mind that acidic foods like tomatoes will break down the protective patina and may make foods stick more readily.

Answered by Josh

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Could a cast iron skillet change its ways and be kosher for a vegan?

Question

If this sounds like a ridiculously neurotic question, that's because it is. That said, and discussion aside, according to Par[e]ve kitchen certifications and ordinances around the world (and especially in the United States), how can a seasoned cast iron skillet that browned a flank steak one night, be redeemed to serve an observant vegan or strict kosher meal the next?

What are ideal steps/rituals/best practices for rendering it compliant with:

• Practical, reasonable steps to assure cross-contamination does not occur (i.e. should I take any special steps beyond a salt scrub?)
• Any general religious observance could conscientiously be observed (an answer here would simply rely on advertising, and any regulation upon it based on health inspections or public safety departments)
• Any strict religious observances

This is not a question about how to clean a cast iron skillet. I just don't want to have to bury mine in the yard in some odd ritual, but I want to know where people would stand based on any additional cleaning/sanitizing/sanctifying measures I might take.

Asked by mfg

Answer

Your issue revolves around 2 things:

1. Some vegans have a tendency to be a bit fanatical. Whatever cleaning you may do is strictly based on whether or not they want to 'accept' it. There's no 'official' guidelines, especially considering the different types of veganism. If you're worried about cross-contamination of fatty oils (which is the only thing I can think of that would be be an issue), then a very light wash with soap is your best bet. A salt scrub won't take care of the oils. If your pan is well seasoned and the coating is solid, a light wash definitely won't hurt it.

2. The kosher part is going to be trouble. Koshering is a very specific religious thing and effects all parts of the food prep from pans, utensils, even storage containers* on the way to and from the plant. Compliance with cooking fully kosher is quite difficult to achieve if you are not set up for it. The process is pretty specific and changes depending on different things in the kitchen. It appears to take at least 24 hours as well. Some other sources seem to imply that you can't, but on further inspection, you can. It's just if you kosher an item, it must be kept with other kosher items.

* _{For my job, we even monitor and help with the rabbi that comes out and inspects the rail cars shipping the product to make sure that they're kosher.}

Answered by rfusca

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No oil on non-stick pans?

Question

My boyfriend is convinced that a non-stick coating on a pan (Teflon, seasoned cast iron, eco-ceramic, what have you) is equivalent to eliminating the need for using any cooking oil whatsoever.

Is this in fact the case? I'm fairly sure that it only reduces the amount of oil necessary to keep things from sticking, but I'm having a hard time proving this (other than the empirical tests that keep failing). Essentially, he is a huge fan of fried eggs, but is trying to avoid the eventual heart attacks.

Asked by Hannele

Answer

There are two parts to this question, the stated part, and the unstated "are you really frying an egg if there is no oil?"

For the first part, most manufacturers of non-stick pans claim that their product makes oil unnecessary, and generally I've found that to be true. A little oil helps, but "necessary" might be a stretch.

To maximize your non-stickyness of a non-stick pan, you should always preheat the pan before adding the food, at least to 250F or so. Preheating causes the teflon to expand a bit, closing up pores and micro-scratches in the surface.

It is also common for oils from the past to form a polymerized layer on top of the teflon, making the pan more sticky. This is actually worse when you use aerosol spray oils, because the tiny droplets hit the pan and very quickly polymerize to form a slightly sticky layer. This layer is similar to the one you intentionally create when seasoning a cast iron pan, but in this case it is not helpful. All-Clad recommends periodically cleaning teflon pans with a light scrub of baking soda and water to remove that coating of oil. It should bring back the maximum slippery of your teflon.

When cooking protein-rich foods, you can also minimize sticking by letting the food cook a bit before attempting to move it. The loose, floppy denatured proteins in an egg are extremely sticky, but when they coagulate (set) from cooking, they become less sticky. It may seem impossibly sticky at first, but may release on it's own after a minute of cooking.

As to the second, unstated part, oil provides flavor, and is also a heat-transfer vehicle. When the food is on the pan, if you looked at it with a microscope only a small portion of the food is actually in contact with the pan. Those areas will get heated more, and other areas will get heated less. A little oil fills those gaps, causing more even thermal contact, which allows fried food to fry, rather than just get burned in some areas.

It is really a matter of taste whether the flavor of the oil and the way that it changes the texture of the food is appealing to your boyfriend. I wouldn't like it without any oil, but if he does, well, so be it. If he doesn't really like the taste, but is concerned about health, I'd suggest using a little olive oil - it has no cholesterol, is low in saturated fats, and has a good flavor. Different than butter, but still very enjoyable.

Answered by Sam Ley

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What oil is best for seasoning a cast-iron skillet

Question

I just cleaned up a rusty cast-iron skillet and I would like to season it. The thing is that I don't have lard handy and I'm wondering whether any of my other oils and fats would do.

I have: canola, olive, sesame and almond oil.

Also, I've heard that appying the oil and reheating multiple times improves the seasoning. Is it true? How many times does it make sense to repeat the process?

Asked by ddimitrov

Answer

This question has been answered several times as part of more general questions about seasoning. See the (closely) related links in the related questions list. This one in particular: What's the best way to season a cast iron skillet?

Specifically about oil- you want to use an oil that has a high iodine value: http://www.journeytoforever.org/biodiesel_yield.html#highiodine

Of those you listed canola (rapeseed) would be highest. If you can find soybean oil it would be even better.

These oils polymerize more easily. To create an even coating with good adhesion, multiple thin coats work well. I have read of people doing as many as 6 coats but, in my opinion, you should do at least 2 or 3.

Answered by Sobachatina

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What are preaseasoned cast iron pans preseasoned with?

Question

I'm shopping for new pans right now and keep seeing cast iron advertized as "preseasoned". What does this mean? What are they preseasoning it with?

Asked by Jonah Braun

Answer

They're pre-seasoning with some sort of fat. It varies by manufacturer, though soy is probably fairly common (its both cheap and has a high iodine value). For example, Lodge uses soy oil.

Answered by derobert

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Using cast iron on a glass range

Question

I currently rent, and the only problem I have with the house we're in is that it has a glass-top range. I absolutely love my cast iron cookware, and use it as often as possible.

I've heard a few reasons not to use cast iron on glass, including:

1. You can scratch the glass if you're not careful
2. It's very easy to break the glass if you drop it
3. You can melt the glass top (mentioned in linked thread)
4. It can be hard to minimize hot spots

I'm not very concerned about (1) and (2), as I've already been using cast iron on glass for years with no problems (I'm very careful when I do use it).

While researching (4) I came across (3), something I had never heard before. So, I now have a few questions:

1. Is melting the glass really plausible? This seems unlikely to me, as a quick search revealed that lowest melting point for common glass types is 1500C or higher, a temperature I have no plans to reach - but I'm not a physicist or a chemist, nor do I know what kind of glass is used to make a glass top stove.

2. Is a heat diffuser effective on a glass range? I have experienced a few hot spots on my large (12") skillet, and obviously when experimenting with my two-burner griddle. Would a heat diffuser help, especially with the two-burner (which I've all but given up with on glass for now because it's so uneven).

3. Any suggestions for safely and effectively using cast iron on a glass-top range (short of being very, very careful when moving the pans)?

Answer

I also have a glass-top stove at home. So far, I really like it: the heat is very even and there is good heat transfer, provided the pan makes good contact with the surface (one skillet I have has a bit of a lip, which makes it heat more slowly).

I've slapped skillets and pots full of water around on mine, and have yet to break it. I'm probably more careful than I would be on a metal range, but it seems sturdy.

But to your points:

1) There is no way cast iron could melt the glass. Iron melts lower than does glass (1200*C vs. 1500*C), so before you manage to melt your stove, your pan will be a puddle. It may, however, be possible to deform the stove top if you let an empty pan heat for some time. I don't see why this would be more of an issue with cast iron than with any other piece of cookware.

2) A heat defuser will work fine. Don't get the kind that is designed for use with gas, but anything else should work fine.

3) The burners on my stove are smaller than my skillet, so I find I need to move the skillet around to heat the edges. Also, flat-bottomed pans and pots seem to be much more effective on the flat glass top, as conduction seems more effective than radiation here. I polish the bottoms of my pots to get better heat transfer, although this is just me being anal.

Also: cast iron can't scratch glass. Glass is much harder than iron (see this wikipedia article), glass having a 6-7 on the Mohs scale, iron having a 4.

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Why reoil a cast-iron pan after usage?

Question

I've been recommended to reoil my cast-iron pan by letting it absorb some oil on the remaining heat of the stove before drying it, each time after using it.

Is it important to do so, and what difference does it make? There should still be a lot of fat left from simply rinsing and drying the pan.

Answer

AFAIK you need to heat the pan to let the oil oxidize and polymerize¹ so that it will form a chemically protective and non-sticking coating.

If you wash your cookware with soap you will have to do it every time. For that reason some people don't wash cast iron at all and wipe it with a clean cloth or paper towel after using. (Burned oil is apparently not very tasty to bacteria and fungi so your pan stays relatively clean and bug-free.)

From my personal experience, meat sticks to untreated cast iron like glue, but on a well-maintained thick iron pan it glides like on Teflon.

__

¹ I don't know if it makes any chemical sense because all references to polymerized fats I could google up were in relation to reoiling (seasoning).

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How much could I safely heat a content-less cast-iron pan?

Question

To which temperature could I safely heat my cast-iron pan on the stove, without any contents? I don't want to re-season it afterwards. Afterwards, I'd just let the pan cool off in room temperature. The base is ~0.5 cm thick.

Answer

If it is completely empty, you probably can't reach dangerous temperatures with your stove. The iron itself melts at 1500°C. The seasoning can be burnt off at much lower temperatures, a self-cleaning cycle in the oven is enough for it (500°C). I have taken an iron pan to above 400°C without damaging the seasoning. (I don't know exactly how high it was, my thermometer doesn't go above 400°C). This was on an induction stove set at maximum, I doubt that any other kind of stove can produce such temperatures.

Edit I just heard an example showing that you can take a pan on a resistive stove to above 500°C with prolonged heating, so you should be measuring it if you plan to go that high. (and if you have a thermometer in this range, you can post your findings to further limit the range of 400° to 500°C, because I'm curious).

But if you say "no contents", be careful that it is actually just the pan. You cannot oil it, because the self-ignition temperature (of flash point) of vegetable oil is low, Wikipedia gives it at 327°C. It could just smoke terribly and throw a spark or two when you reach it, but it can also flame up and then you are holding a small brand in your hand.

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Do you season a cast iron waffle pan before using?

Question

I just bought a cast iron waffle pan. I've seen conflicting advice about whether it should be seasoned. I have several old cast iron pans and my instinct would be to season it but I've also read that in a waffle pan the seasoning will get gummy and the waffles will stick to the pan. Some sites recommend just brushing the pan right before pouring the batter in. What are your thoughts?

Answer

I see no reason that a cast iron waffle pan should be treated differently in regards to seasoning than other cast iron. Since it won't be cooking anything with significant fat in it naturally, if anything it may be more important! Seasoning is both for non-stick reason and non-oxidizing reasons.

Season it well on your own, then use it with some fat (of some kind) very lightly brushed on to keep it well. Only brushing right before use will keep one good likely, but would take a long, long time to naturally season since a large portion of the fat will immediately get used by the food.

Cast iron gets gummy if you either 1) season with a spray like Pam consistently or 2) don't cook your seasoning long enough and/or high enough. Use a fat, bacon fat, would be great here and season away - properly. In regards to seasoning, I recommend checking out this question, as its unneeded to replicate detailed information elsewhere in the site.

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Left my cast iron on the hot burner, now what?

Question

So the other day, while baking off excess water after washing, I spaced out and forgot it was there and headed upstairs for say, an hour. When I got back down the pan had a white-ish ring in the center. After cooling and scrubbing it down it appeared that the seasoning had been vaporized in the area that has the ring.

I oiled the pan to prevent rusting and haven't gotten back to it in a week or so.

My question is: Should I remove the seasoning from the rest of the pan or should I just re-season the whole thing? If I should remove the seasoning, what is the best way, I think I read some on here but I haven't been able to get back to it. I recall possibly using the clean cycle of the oven?

There's plenty of info on here about seasoning so don't worry about that!

Feel free to make jabs at the space cadet too, I beat myself up about it until I realized the pan wasn't completely ruined!

Answer

Personally, I'd just season the pan a couple times to cover the spot; it seems excessive to strip off all the other seasoning and start from scratch unless the pan is really deeply rusted.

Other people may feel differently, of course; there are as many opinions about caring for cast-iron as there are people that own it.

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Keeping food warm: does cast iron make a suitable potluck vessel?

Question

I'm making this hash recipe for a potluck at work tomorrow.

Tonight I did all my prep:

• Peeled, diced, roasted the sweet potatoes
• Diced the onion
• Diced the apples (stored in water w/lemon juice)
• Cut the bacon into lardons
• Sliced the green onions

So tomorrow morning should be a strait-forward "pluck from the fridge, heat it all up" affair. I was initially going to do this in a big saute pan but am now considering using my lidded cast-iron fryer. Basically when the hash is near done, I could just put the whole lot into a bag (w/proper heat protection, of course) and head to work.

My questions are:

• Will the reactive qualities of cast iron be undesirable for this type of "longer term" food storage/serving?
• Will the hash actually stay warm for the 2.5-3 hours I'll need it to?

If anybody has better tips for keeping a hash-like dish warm long enough for a lunchtime potluck, I'll take em!

Answer

All the cast iron pans I've got came with instructions that read along the lines of "suitable for serving, but not storage of food".

I'm not sure what would suffer most though, your pan, or the food, or both, depending on length of time. My guess is that the length of time you actually can store food in a cast iron pan/pot safely somewhat depends on the ingredients used. For example, a tomato sauce would be less good to store in a cast iron pan than fried potatoes.

Regarding the temperature, I'd say it depends on how well insulated your "bag" is. Cast iron distributes temperature very nicely, but that doesn't necessarily mean it will cool less quickly than another type of pan (of same size/thickness) when taken off the heat.

Regarding keeping food warm, I did see insulated pots similar to a thermos flask you'd use for hot coffee or tea, which are made to store food. They have a big enough opening to be filled, and to be eaten from.

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Wok: Carbon steel or cast iron?

Question

I LOVE stirfrying (I probably do it 4 times a week) and I want to take it to the next level (or 2). I am going to get this burner to cook my stirfry's out on the patio.

I am wondering if I should also get a cast iron wok, or should I just stick with the carbon steel that I have been using?

Answer

I have friends from Hong Kong who always use steel woks in their take-away.

A cast-iron wok would require a different technique for stir frying. It would be slower to heat up and retain heat when you didn't want the food to continue cooking.

Stick with the one you have ...

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