Chemistry of Cast Iron Seasoning (2010)
sherylcanter.com
sherylcanter.com
In "Perfect Popovers" [1] she advises Avocado Oil for its high smoke point, out of fear that letting the oil smoke will release carcinogenic free radicals into your food.
Then in this "Science-Based How-To" (three weeks later) she switches to flaxseed oil and suddenly isn't concerned about the free radicals anymore.
There is no hypothesis testing, and there are no measurements of free radicals or polymerization. It's all conjecture.
Her third post [2] calls out "black rust"/magnetite as a key component of seasoning cast iron, because "someone sent me some links". The links are not provided.
I have no problem with her blogging about her experiences seasoning cast iron, but what she's doing is not science, and it is misleading to call it "science based". If the author were a chemist, biologist, or nutritionist, I could defer to her education and wouldn't be writing this comment. But her bio [3] doesn't indicate any such training.
[1] http://sherylcanter.com/wordpress/2010/01/perfect-popovers-a...
[2] http://sherylcanter.com/wordpress/2010/02/black-rust-and-cas...
1. Get the oil hot before you add any foods.
2. Use a sheet-metal spatula/flipper
Humanity has known for a long time that when you get your cooking oil hot, it repels food instead of binding it to the cooking surface; but the amateur cook has forgotten because of a reliance on non-stick surfaces.
The sheet-metal spatula/flipper lets you clean the cast iron with each pass of the tool. A rubber/wooden tool will leave small, burnt on bits of food, which accumulate more bits of food; a sheet-metal tool with scrape those off before they become a problem. Also, a sheet-metal spatula will scrape the roughness of the cast-iron from the bottom of your pan over the course of decades, moving you towards that inky-black mirror of grandma's old pans.
I can cook anything on my cast iron, just by following those steps, even fried eggs: the surface is totally non-stick. And cleaning is simple too: sometimes I'll make a few passes with the spatula to scrape off any food that has dried on, but that's all I ever do.
I really don't think that will happen. The reason your new cast iron pan doesn't have that shine is because they've changed how they make them.
A few things I do:
Use wire mesh to clean, quickly, immediately after cooking.
Only use tap water to clean it. No detergents. This allows the pan to develop a literal taste of its own after a few months or years.
Heat the pan after cleaning, evaporating all water.
Don't do that. It causes rust.
Metal rusts MUCH faster when hot than when cold. If you have wet metal that you are worried will rust get it as cold as possible, and let it dry. Best place is in the fridge - it's cold, plus low humidity helps.
A fridge is not necessary for cast iron, but don't heat it when wet.
The point is don't warm it to dry thinking it will rust less since it's wet for less time. Just let it dry in regular air.
If it dries say 50 times faster, does iron rust more than 50 times faster at 400F than at 70?
I have no way of knowing either way, but I've got a cast iron pan that belonged to my great grandmother and I remember my grandmother heating it to dry it off. My mom did the same with it, and now I've done the same--no rust.
I took two identical pieces of metal. Dried one in a warm stove the other on a table.
The one on a table had no visible rust. The one in a stove was completely orange.
There's a pretty big difference between drying something in a warm stove vs applying a direct flame to it on the stove top.
It takes just a few minutes to get the skillet hot enough where the water pretty much instantly evaporates. I'd imagine putting it in a warm stove took much longer to completely dry it.
Reaction speed doubles for every 10 degrees F, but evaporation doesn't.
What I said was that if you are heating the iron in order to speed up evaporation to avoid rust, you are being counter productive. You will avoid more rust (if any would be formed in the fist place), by just letting it air dry.
That can't possibly be correct, or at least it's only correct over part of the range.
If a pan rusts at a given rate at 70F, it would rust at 2^33 times that at 400F--those numbers just don't work at all.
Also once the pan heats past the boiling point of water, there is a huge decrease in drying time.
But it's certainly not helping.
The methodology was not complicated: I washed some porous/rough metal under the faucet, dried it with a paper towel, then put one piece in the oven at 170F, one on the table.
300-400 (what you'd get from the stove top) is above the boiling point, so the water rapidly boils off.
These 2 things aren't comparable.
Here's a counter example: There are many tons of metal in hot desert climates that have a small amount of rust on them, but nothing like the kind of rust from a cold wet climate. There may be complications from cooking, but, and this is without giving it much thought, I'd say that water is a much larger factor than heat.
You still need water.
For stuck-on food, I've had best luck with a coarse copper mesh pad (e.g. Chore Boy), which I use lightly, and only to remove the gunk.
In the past, I'd also used coarse salt as an abrasive, but I like the copper wool better.
I also heat the pan to dry it off. As to the comment about this promoting rust: if you have a well-seasoned pan, you don't have any wet metal; you have a wet seasoned pan. You could just as easily dry it with a dish towel, but this tends to get your dish towel dirty.
1) Buy a used cast-iron off ebay. The old cast irons were machined smoother. Anything you buy new from lodge today is going to have a texture like low grit sand paper. Any old Wagner or Griswold is going to have a much smoother base surface.
2) Make sure you get everything off your pan. If you did buy a new pan, they often have weird artificial seasoning on them. If you have an old pan, anything loose can provide a failure mode for your new nice coat of seasoning.
3) Don't get 100% of the oil off between coats as the article suggests. You won't build any seasoning.
4) Consider using Canola oil. The flaxseed oil that you buy seems to have some particulate matter that is noticeable in the finished seasoning. That or I didn't shake mine enough.
5) Consider doing this at a time when you can open all the doors/windows. Even if you stick to the really thin layer, your house will still get a smelly smoke.
6) Don't leave anything nice on the top of your stove. My oven vents out over the burners, and a Le Cruset pot resting there got covered in a sticky residue that was a pain to clean off.
More background:
I tried this with a beat up hand-me-down wagner about a year ago. I did six coats of flaxseed while following the instructions to "get all the oil off" with a towel after each application. The result was a pan with basically no seasoning that everything stuck to.
I went back and repeated while leaving a thicker layer (still not oil pooled or anything, but noticeably wet/shiny). This worked much better, and left a decent coat on the pan that things don't stick to. Sadly I did not strip the pan back down after the first misadventure, and some of my nice seasoning is now peeling around the corners.
Running it through a simple coffee filter might fix this.
I'm guessing that you buy unrefined flaxseed oil, and that you keep it refrigerated? That's what you should be doing, and it's all well and good. But unrefined flaxseed oil contains a mix of fatty acids with different melting points. Some of these solidify under refrigeration, and give the appearance of being particulates when poured or used.
Maybe you can bring it to room temperature (to something like 25C) before using
just don't pay retail.
cast iron is for hipsters
Yes, and it would be foolish to use cooking utensils preferred by a group of people who likes simple, time-tested tools and methods to cook tasty, balanced meals using high-quality ingredients.
The type of pan you use has no bearing on this.
Its foolish to use something that performs worse than something that also cheap and readily available.
Thats just called ignorance.
Try a de buyer or a mafter and then come back and update your post.
In any case, although I have no current plans to replace my cookware, what should I expect in improvement upon switching to said less ironic brands? Less food sticking? Better heat distribution or other characteristics?
1) long handle, low sidewalls, medium volume
2) medium weight, low center of gravity
3) smooth machined surface
http://www.seriouseats.com/2014/11/the-truth-about-cast-iron...
One of my personal favorites is on making the perfect french fries:
http://aht.seriouseats.com/archives/2010/05/the-burger-lab-h...
http://www.seriouseats.com/recipes/2013/01/foolproof-pan-piz...
Its bang for a buck of effort is absolutely off the charts :)
If you have some time, it's even better if you can age the uncooked dough in the refrigerator for 3-4 days. You get bigger bubbles and better texture.
I use a recipe for making loaves of plain old white bread that requires making a biga ahead of time (Cuisine at Home, Feb. 2003 p32-35). It's impossible to eat store-bought bread after that.
If anyone's curious about this specific recipe, I could either email you a scan or post it here.
[1] http://www.cookingforengineers.com/article/50/Smoke-Points-o...
Even when a reference is provided, the reference itself isn't reliable. Cooking seems to be slowly emerging from the dark ages, but there is still a lot of pseudo-science that most people unfortunately don't even realize is exactly that.
Once you get that base coat really solidly on, you shouldn't ever have to hit your skillet with anything harsher than water and a rubber spatula.
I also leave my skillet in the oven as a thermal mass, but that's another story.
Rubber spatulas aren't recommended for cast iron. You're much better off with a metal spatula as long as it has a straight edge.
Not necessarily a sound rational basis for it, but it's at least less gross in my head, which is enough reason.
Cast iron is a lot less maintenance than people think. I cook food too hot for Teflon, scrape the crap out if other pans, and like to throw things in the oven. I also use a metal spatula for everything. I pretty much do all of the things that these sites say not to, and never have problems.
they work fine and produce great results with my heavy duty metal utensils (spatula, tongs). they can easily produce non-stick eggs and fish. i can brown->roast without worrying at all about the pan. i have also destroyed every other pan i have ever had, and have learned my lesson - i just won't buy those precious non-stick or anodized or ceramic pans anymore.
to me that's the beauty of cast iron - superior results without having to treat it well. i thought that was obvious but apparently some people have a very different take on it!
The only thing I really do is to: use it, immediately clean it, put it on the stove to heat and dry, then wipe on a layer of whatever fat I have at hand. Really, the last step is the only difference from how I treat most pans (yes, I dry them with the heat from the stove). I have done the real seasoning thing, but found it both a pain and not noticeably more effective...
I looked online for just about anywhere in Northern California and made phone calls to various kitchen stores and iron workers up to a radius of about 25 miles and found absolutely nothing. I would much rather have just paid someone who knows what they're doing to re-season my cookware than half-ass it myself. So does anyone else know of a service for this?
My family will actually eat healthier food after I read this article since "Dad's panfried stuff" will no longer be so carcinogenic :)
There's a traditional black smith's finish to make an almost indestructible coating by rubbing some beeswax on steel heated to the smoke point... I imagine it's the same process when seasoning a cast iron pan with cooking oil.
BTW, There seem to be a lot of people looking for cast iron pans... Keep a lookout at garage sales and swap meets. You can usually find pans without too much trouble, and for around $5--$10 or so.
As far as seasoning goes, I just wipe some olive oil on and heat it 'till it smokes, let it sit, and repeat three or so times. As far as I can tell the oil forms a tough plastic-like coating. The only thing that'll damage it in normal use is cutting into it with a sharp knife or the edge of a spatula, or burning the coating off by getting the pan too hot. Flax oil max stick less, or be slightly better in some other way, but I doubt there is much of a difference.
http://www.houseofpaine.org/CastIron/
Scroll down to "The Recipe for Perfect Cast Iron Seasoning" and compare with her "The Recipe for Perfect Cast Iron Seasoning"
I remember reading that other webpage some years ago, while her post is brand new. This kind of un-credited copying might well be called "plagarism"
Either way, it's kind of interesting. Nice find.
EDIT: ignore what I said about 1999. Clearly wrong now that I looked more at that page. They even reference 2000 in the House of Paine page.
Other than your recollection, I can find no evidence that Sheryl plagiarized this article from HouseOfPaine.org. Additionally, the archived version of the first blog post from House of Paine confirms that they intend to republish copyrighted material of others without authorization:
This website contains copyrighted material the use of which
has not always been specifically authorized by the
copyright owner. houseofpaine.org is making this material
available in our efforts to advance the understanding of
economic policy, educational, environmental, political,
human rights, democracy, scientific, and social justice
issues, etc. We believe that this constitutes a “fair use”
of the copyrighted material as provided for in section 107
of the US Copyright Law.
While this statement doesn't offer any confirmation, it seems fair to say that their beliefs regarding fair use are not in line with the usual interpretation of the courts, and indicate at least a willingness to commit acts that others would typically refer to as plagiarism.
1. clean the inside of the pan of any oil, run it through the dishwasher, and then clean it with acetone. (you are doing this so the oil doesn't build up in the sandpaper, and keep it from cutting)
2. get several grits of sanding discs for a random orbital sander. 50, 80, 120, 220. Also get a fine particulate mask. Iron ground with 220 grit paper makes some very fine dust.
3. start sanding the inside of the pan. for a 10 inch pan, this took a while, but it will successfully grind away quite a bit of metal.
4. once you are done with the 220, it should be much smoother, then you can clean it with soap/water again, and then begin the seasoning process. I seasoned my pans outside on a grill.
Non-waterproof sandpaper works better on soft materials like wood because it tends to "load" less, so it lasts longer.
If you hand sand, you could use Silicon Carbide paper (the black stuff labelled "waterproof"). This would minimize dust, but cast iron is very very hard, and would probably be difficult to sand evenly by hand.
I used to own a pizza stone that seemed to transfer a lot of heat to my bread, even though it was relatively thin and didn't feel very dense. Bread and pizza would brown nicely on it, even though it was too small for baguettes. One day it cracked and I bought a different kind (Ceramic Chef brand). It's a little thicker and feels more porous, and I just can't get crisp bread on it even after pre-heating it in a 500F oven for 30 minutes. The new one is definitely a different type of stone. Maybe it's engineered for people who want to cook on rocks but don't like crust?
I'm excited about baking on a large slab of cast iron. I've had a 12" cast iron skillet for ~15 years and use it all the time.
[1] http://www.katom.com/067-1016905.html (store link; the manufacturer only describes it in detail in a PDF)
I've got a newish, rough Lodge and a vintage smooth Wagner that I both stripped and reseasoned (with just Canola oil. This flaxseed method is overkill IMO). The Wagner can cook eggs like teflon; the Lodge, even after two years of heavy use is still pretty rough for eggs, its nonstick enough for most other foods.
Cast iron is nice and I prefer it for its properties besides the nonstick abiluty, but for the casual home cook making eggs, Teflon is pretty foolproof.
But a rudimentary seasoning is really easy:
Wipe some oil over the pan. Use as [high temp oil] as possible, but whatever you have will work. Wipe off any access with a paper towel. Put it in your oven at 230(C)/450(F) for at least 30 minutes. (careful it will smoke a bit).
I couldn't recommend using it at all without some base layer of seasoning. It's really easy to do and lasts quite a while, even if you don't follow the articles really thorough methodology.
source: me - frying with cast-irons twice a day for 10 years
[high temp oil] aka those with the highest "smoke point" http://en.wikipedia.org/wiki/Cooking_oil#Types_of_oils_and_t...
If you don't want to use flax seed oil, just use canola oil.
Doesn't it just provide a very hot surface that boils off any local moisture? That's would happen with a cast iron skillet.
It would explain why cast iron pans or glazed earthenware is used for baking no-knead bread.
Still, you can't beat cast iron for durability and ease of cleaning.
In German speaking media, the universal recipe I found is to use any high-heat oil (canola, sunflower, etc), fill the pan with a lot of it (3 mm of oil in the pan), then add potato peels and a lot of salt. Fry the peels (and flip them in the process) until the peels are completely charred, done.
I haven't tried either.
I'm fascinated by cast iron cookware, the durable nature of it seems to contrast with so much of the rest of our lives. Take good care of it and it will last generations!
My cast iron pans are awesome. They cook the best steak and they have been in the family for generations. I remember eating some good steaks as a kid that were made in those pans and now I use them myself.
I do understand how non-stick pan mfgrs stay in business, because they're guaranteed about two sales per year due to amazingly low product durability. I have no idea how Lodge and the others stay in the CI business because the pans last forever. Its a mysterious business model.
One more point to add is I have CI grates on my charcoal BBQ and a similar seasoning mindset applies to CI grill as to frying pans. Dump the coals, scrape/scrub the grates, apply some oil/crisco while it'll still smoke a little but not too much, you're good.
Another non-stick alternative I cook with a lot is stainless steel. If you're generous with the oil and keep the temps very high but not too high and start with a surgically clean pan, you can fry in stainless. "Barkeepers friend" is the best thing I can find for cleaning stainless. Stainless is also basically eternal. Unlike CI, if you're used to spending $50 at Target for a non-stick pot or pan, a CI equivalent will be like $15 but a large stainless pot could be maybe $100 to $150 for all-clad? I'm in the "all-clad or nothing" tribe of stainless users, there are cheaper alternatives. I like a steak in a nice near red hot stainless pan. You'll need the "barkeepers friend" cleaning powder after that. I could imagine that powder would strip a CI pan pretty well, given how well it strips baked on stuff off stainless pans.
I haven't seen more high end antique pans first hand, but my understanding is that they were factory-polished, and that this step is somewhat costly.
"Cast iron seasoning" is a scam. There, I've said it. I've got a full set of cast-iron cookware and have made repeated furtive and unsuccessful attempts to use it it over a period of 30 years. It just doesn't work. You _will_ inadvertently put tomatoes or lemon juice into your skillet, it _will_ lose it's "seasoning", and you _will_ attempt to "re-season" it with only 25% success rate but a guaranteed 100% stinky and smoked-out household (complete with 9 smoke-alarms beeping) rate.
Instead of giving someone cast iron cookware (akin to giving someone herpes, but slightly less intimate and curable), give them a teflon skillet - it will work immediately and unfailingly. It will lose it's charm slowly and gracefully (instead of the first time it is cleaned, as with a cast iron skillet). They will know when to replace it.
Let the posts from the alleged hundreds of blissfully contented cast-iron skillet users now commence.
Don't get me wrong, I use and love both my cast iron and a few old All Clad stainless with copper cores. Teflon will never sear as well, never give you the ultimate maillard you're looking for.
But you can crack an egg into a teflon pan without oil and slide it out without leaving a trace.
a) Why attempt to make judgements about how other people "feel" when you simply don't know. For example, in this case I feel neither "rightious" nor "validated" from what others post. Instead I _know_ from my own experiences over several decades how cook-unfriendly cast-iron cookware is.
b) It's "righteous", not "rightious". Perhaps you could enable a spell-checker. It is much easier to read posts with correct spelling (and grammar).
This line is pointless baiting and your post would have been better without it.
https://news.ycombinator.com/newsguidelines.html
> Please don't bait other users by inviting them to downmod you.
Your spelling lame in your follow-up post is just rude and again needlessly baiting.
Pointing out a misspelling, even if only one of tens of thousands made on this and other Internet groups, is simply a honest reminder that literacy is valued even on the Internet. I said nothing rude. Your calling the correction "lame" _is_, however, at the least ambiguous and at the worst truly rude, since you may be making (incorrect) assumptions about my internal state of mind.
My Favorite Article on Cast-Iron Skillets:
"Why Do I Have a Cast Iron Skillet? By Sonia Saraiya
http://therumpus.net/2012/06/why-do-i-have-a-cast-iron-skill...
I make tomato (or other acidic things, like spinach or chard) stuff in it fairly regularly and as long as I clean it within a few hours and give it a little mini-seasoning (re-oil, cover with lid, set on hot burner for awhile, turn off and let return to room temp while covered) it's fine. Keeping it covered is key to minimizing the stinky house problem.
Maybe if I followed the article I wouldn't have to do that, but it's just not that hard now that I have the habit and I really like the cooking characteristics of cast iron (how well it holds heat, etc.) so I'm going to stick with it (pun intended ^_^ )
My experience is a counter-example. I've been using my iron pan for years and I've never had those problems. After I bought it used, I cleaned off the gunk, rust spots, and dust bunnies with soap, water and steel wool. I dried it over the burner, and wiped it with some oil. I wiped away the excess oil, and that was it. No oven-baked seasoning process.
To clean after cooking, I usually just wipe it out. Every now and then I do a more thorough cleaning, essentially repeating what I did when I first bought it. Wash with soap, scraping with a spatula to get stuck bits off. Dry it over the flame, and wipe on a thin layer of oil, and wipe off the excess. When I'm done, I can sometimes see a dull reflection of myself in the bottom of the pan. It is quite smooth.
I have cooked with citrus, tomatoes, vinegar, alcohol, etcetera. It is not "non-stick" enough to cook eggs or fish without oil, and usually those foods necessitate washing. I have never had to do a bake-on seasoning process. I have never started a smoky grease fire with it.
More high-maintenance than a stainless pan, certainly, but I like the cooking characteristics. I like that I can scrape hard with a metal spatula to release food after searing. I like that it reacts to temperature changes more gradually. I like that it heats with a significant temperature differential. I like going from stove top, to oven, to broiler, to grill, to wood fire without damaging the pan.
Using cast iron is simple. Take a pan, throw in some oil, cook, clean, wipe down with some oil. I grew up using nothing but cast iron skillets and all of this talk about how only a perfect organic oil combined with a special oven can create a decent seasoning is bs. I use vegetable oil and they work fine. Also, my pans have a sandy surface and they work fine. I didn't buy mine at an estate sale, but at a store years ago and they work fine.
I fry food in mine, stick it them the oven to bake, make eggs, steaks, bacon, vegetables. I pretty much cook everything on cast iron because it is easy to take care of and lasts forever. People turn this into something it isn't.
I also grew up making lots of bbq in Texas. People do the same thing with bbq - they spend so much time working on perfecting their tools that they forget to cook the food.
Why risk the PFOAs? Just get enameled cast iron or carbon steel.
An example from the article:
But it’s not a good idea to use a spray oil, no matter what oil it’s made with, because of its additives. You’re doing chemistry here. If you want good results, use pure ingredients.
It's a compelling argument, but it's not science-based. Where is the evidence that additives affect the seasoning or polymerization? It could very well be that additives have no effect, or more likely that it depends on the type of additive. If this was the only example, that would be fine, but the blog post is full of examples like this. There is no citation of any scientific source anywhere in the article!
If you are writing articles than claim to be science-based, you really should link or cite actual scientific literature. (Or run your own experiments!)
Ruling out some experiments to try is often necessary, because time. However, it is far preferable to use prior evidence to rule them out, not speculation. No matter how logical it may be.
And you are doing a bit of goal post shifting. Nobody is asking to try all ingredients and isolate everything. But it was never even established that a spray oil wouldn't work. Just speculation as to why it wouldn't.
I will throw out that, for myself, I think the majority of the effort that most people go through with their cast irons is for cosmetic purposes and failing to realize that we use much milder soaps today than we used to. If you want a decently seasoned cast iron skillet, just commit to using it consistently. Will it be pretty? Probably not. But it will work just fine.
The thing is, there's not one 'spray oil additive' that everyone uses they could even test. They could just say: "Spray oils use additives that could complicate this process and each spray oil is different. We didn't test them and don't recommend that you use them. Using real, unadulterated oil is simple, proven, and effective."
I can't comment on the effectiveness of the overall process of seasoning a skillet, nor was I.
That is, you are commenting on the process. Specifically, you are saying that spray oils are bad for it. And then giving a quick (and appealing) argument for it. However, the question is when and how was this established.
Additives are a random addition that serve no purpose in the process of seasoning a cast iron pan. They didn't test for throwing a handful of salt or baking soda in either. Nor should they. There's no need.
You brought up that it would complicate things. Of course it would, but that is basically beside the point.
Edit: apologies, I should say with no evidence, not reason.
Name the substance and you can get a better answer
You'll see a brown residue on the sides of the pan -- that the stuff.
The residue issue is more pronounced in thick/dark pans like cast iron that retain heat for a long time -- unless you clean them immediately, the residue cooks on. If you cook some eggs, eat, and go back to clean your cast-iron pan, the oil will have been cooked on.
The solution for this use case is to use something like the "Misto", which is a spray pump that lets you spray plain oil on a pan.
The lecithin might make it worse, though.
Moreover, I think the article is fairly scientific in spirit. When she had to make judgment calls, she described how and why she chose the option she did. A scientific research article doesn't have to settle every question it raises and do every possible experiment. It just needs to be clear about what it did and didn't do.
That sounds deeply unscientific.
Another thing I agree with her WRT respiration you'll breathe less smoke over your lifetime if you use the best finish possible.
After cleanup, I make an art form of heating up the cleaned and oiled pan right up to smoke point but not too far beyond.
I've never even heard of the authors self cleaning stories about fires and warping. I guess its possible...