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Why can't stainless steel take seasoning?

First, let's check my layman's knowledge of metallurgy (which may not be correct). I think cast iron is 100% elemental iron. Carbon steel is maybe 97% iron, 2% carbon, and 1% other alloying metal. Stainless steel is maybe 82% iron, 2% carbon, 15% chromium, 1% other alloying metal.

So it seems like it's the chromium that's preventing the seasoning somehow since it's the biggest difference from the other two. But I'm not a scientist. Can someone tell me exactly what is going on at a molecular level to prevent seasoning from forming?

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  1. < I think cast iron is 100% elemental iron. Carbon steel is maybe 97% iron, 2% carbon, and 1% other alloying metal.>

    Cast iron actually has more carbon than carbon steel. Pure iron is actually soft/softer.

    <Can someone tell me exactly what is going on at a molecular level to prevent seasoning from forming?>

    There are two things here. It is pretty much a "carrot and stick" situation about seasoning a cast iron cookware vs a stainless steel cookware. First, cast iron takes on a seasoning layer better than stainless steel. Second, cast iron has to be seasoned. It is not an option. Otherwise, foods will stick to the cast iron, it will rust, it will smell...etc. You actually can season a stainless steel cookware, but it is just not worth it if you think about.

    Let's start from a functional point of view.
    Let say you want to able to season your cookware, and that it can handle high heat and maintain nonstick, and you are willing to hand wash this cookware. Well, if you are already willing to season the cookware, and to hand wash, then a seasoned stainless steel cookware brings nothing new to a seasoned cast iron or carbon steel cookware. A stainless steel cookware is more expensive, and it does not take on the seasoning quite as nice.

    If you want a cookware which can go into a dishwasher, and can cook very acidic good, and you don't like seasoning a cookware, then a bare normal stainless steel cookware is better than a seasoned stainless steel cookware. The dishwasher or the strong acids will simply destroy the seasoning anyway. Again, there is no point of seasoning the stainless steel cookware.

    12 Replies
    1. re: Chemicalkinetics

      "It is pretty much a "carrot and stick" situation"

      What do you mean? I can't see how this applies to either the situation or your explanation.

      1. re: FrankJBN

        <What do you mean? I can't see how this applies to either the situation or your explanation.>

        What I wrote is that "First, cast iron takes on a seasoning layer better than stainless steel. Second, cast iron has to be seasoned."

        A carrot and stick for the cast iron and carbon steel cookware. A carrot -- a seasoned cast iron cookware performs much better than a seasoned stainless steel cookware. A stick -- a unseasoned cast iron cookware is practically nonfunctional (in the long run), thus much wore than an unseasoned stainless steel cookware.

        A reward for seasoning cast iron cookware, and a punishment for not seasoning cast iron cookware.

      2. re: Chemicalkinetics

        "Cast iron actually has more carbon than carbon steel. "

        I knew this was the true for the earliest blast furnace-produced cast iron, but I didn't know this was still the case. What's the carbon percentage of a modern cast iron then, 4%?

        "You actually can season a stainless steel cookware, but it is just not worth it if you think about."

        Interesting... so the smooth black residue that people spend lots of time and sweat to scrub off stainless steel, is that actually seasoning?

        1. re: RealMenJulienne

          < What's the carbon percentage of a modern cast iron then, 4%?>

          Cast iron describes a group of metal really, and the exact definition varies. Some say anything above 1.8% carbon, some say above 2.1%. Generally speaking, ~2% is the cut off between steel and cast iron.

          <so the smooth black residue that people spend lots of time and sweat to scrub off stainless steel, is that actually seasoning?>

          Yes, that is something like this:

          http://cooking.stackexchange.com/ques...

          I would consider it to be the equivalent of the carbon steel seasoning.

        2. re: Chemicalkinetics

          Your "Carrot" should still apply to Stainless. I generally buy into the 'a seasoned CS or CI pan is the best thing to replace non-stick' approach, but if stainless can be seasoned, why in the world is no one doing it? Imagine a frying pan, with the improved conductivity of tri-ply (or even a Stainless-lined copper frying pan) that is seasoned to non-stick perfection. That sounds like an almost perfect tool!

          1. re: jljohn

            < Imagine a frying pan, with the improved conductivity of tri-ply (or even a Stainless-lined copper frying pan) that is seasoned to non-stick perfection>

            Maybe, but I think it is probably easier to season on aluminum than stainless steel -- even though it is best on cast iron and carbon steel.

            So assuming I am correct that it is easier for aluminum to take on the seasoning than for stainless steel or that they are about equal. Then stainless steel triply offers nothing on top of aluminum. Straight aluminum has equal or better heat conductivity than triply. Both cannot be put into dishwasher and both cannot cook very acidic food now because they both have to maintain the seasoning. So if heat conductivity is very important to you, and you still want to able to kind of season your cookware, then a cheap aluminum pan is probably better.

            Stainless steel triply biggest advantage (selling point) is in fact its stainless steel surface being chemical and physically stronger than aluminum. Once you have to put and maintain a seasoned layer on the stainless steel, then the chemical stability advantages are gone. I guess what I am saying is that. It isn't completely useless to put a seasoning surface on stainless steel cookware, but it seems there are better options to achieve one's goals no matter how we look at it.

            1. re: Chemicalkinetics

              OK, I can see that. Why then are CS skillets (like the De Buyer) so popular as opposed to cast aluminum as a non-stick option? Is it solely the aversion to aluminum that tends to run concurrent with the fear of non-stick?

              1. re: jljohn

                < Why then are CS skillets (like the De Buyer) so popular as opposed to cast aluminum as a non-stick option? Is it solely the aversion to aluminum that tends to run concurrent with the fear of non-stick?>

                Do you mean cast aluminum to separate it from the typical sheet aluminum? Or do you mean any aluminum? I think, in my experience, that cast iron and carbon steel just tend to produce much more stable seasoning surface. Despite the fact, one can season aluminum pans, most don't. Maybe the seasoning does not stick around -- it isn't as strong as those on carbon steel and cast iron. Maybe it is not worth all the trouble when aluminum pans are usually used for everything -- including acidic food.

                Actually, it really depends what you mean by "popular". Bare aluminum cookware are in fact the most popular cookware sold, way more than carbon steel cookware. Most restaurants use straight aluminum cookware. They are just not that popular in regular household. I suppose a few things. They cannot be put in a dishwasher, they don't quiet take on the seasoning as nice as cast iron and carbon steel pan, they are very easy to warp (bend and dent)...etc. They just look old really fast. I have a couple straight aluminum cookware, and they get scratched, dented...etc very easily.

                Of course, these are just my speculations why other people don't get aluminum cookware, I cannot really speak for them. :)

                1. re: Chemicalkinetics

                  I'm not sure the answer turns on the pan being cast or spun, but what I'm talking about are the restaurant supply store frying pans and skillets that are 3-4mm thick aluminum. I believe the Update brand ones are spun, but I've seen cast ones as well (they tend to look more like the Pot Shop of Boston's Omelette Pan).

                  Regarding my question, let me be more precise. If aluminum can be seasoned well, why does anyone select a Carbon Steel Frying Pan over an Aluminum one? They seem to be about equal on all fronts (i.e. neither can be put in the dishwasher, neither should see highly acidic food, etc) except that the aluminum is both cheaper and more conductive. I suspect that the answer might be that those people who have an aversion to non-stick also have an aversion to aluminum, but I am wondering if you can think of any other reason.

                  1. re: jljohn

                    <why does anyone select a Carbon Steel Frying Pan over an Aluminum one?>

                    Because the seasoning stay on carbon steel frying pan much better. It is much more stable. I have seasoned my stainless steel cookware once, and the seasoning does not last well. Seasoning on carbon steel is already very tough for some people to maintain, and maintaining a thick even layer of seasoning on aluminum cookware is tougher still.

                    <except that the aluminum is both cheaper and more conductive>

                    Agree, which is why restaurants use them all the time. They are cheap, conductive, light, somewhat chemical unstable compared to stainless steel, but much more stable than carbon steel and cast iron....etc. Restaurants often treat them as disposable cookware. Retire them every 2-5 years depending on the condition. So getting them banged up and warped is really no big deal. I don't think most home cooks like to have banged up cookware.

                    <I suspect that the answer might be that those people who have an aversion to non-stick also have an aversion to aluminum>

                    My guess -- that is my guess is a general "no". I think some people worry about aluminum/alzheimer link, but that is a minority. On top of that, I believe the scare really picked started more recently (despite the fact the paper was written in 1960's). Because the scare is more recent, it cannot explain why aluminum did not take hold in household in last 50 years. I mean, afterall, nonstick cookware is hugely popular in residential household. Yes, few people are scared of them, but have you been to Walmart, Target, TJ Maxx? Most of the cookware are nonstick Teflon coated -- despite a few people are scared.

                2. re: jljohn

                  Hi, Jeremy:

                  I think there are several factors that inform an answer to your question. Yes, the (unfounded) aversion to bare aluminum is one. Another is that CS has only recently been mass-marketed for home use. A third is the pricepoint of CS. Still another is the dearth of thick, bare aluminum pans. And let's not forget cosmetics: SS and aluminum, being bright, will *look* grungy and unclean, whereas the CS and CI are accepted as *supposed* to be looking that way. These are almost exclusively market factors, not performance ones.

                  I have come to the conclusion that *all* cooking surfaces (except perhaps borosilicate glass, I haven't scored a Visions pan yet) can benefit from some "seasoning", if the term is elastic enough to extend beyond what happens to CI. IMO, the differentiating conditions boil (really, no pun) down to how well the substrate holds what is laid down. CI and CS tend to take and hold well the multiple layers which polymerize firmly and darken the look of the pan. Tin, silver, aluminum, stainless and the satin ECI far less so. Glossy ECI almost none, but still a little. Heck, I think even PTFE linings benefit from the occasional hot oil treatment.

                  It's another overlooked truism that seasoning on all these pans is being lost with use of detergents, scouring or acidic foods. Again, because CI and CS tend to hang onto seasoning longer, people can get by with doing all those things and maybe seasoning-as-you-go can keep up. The other surfaces, not so much--e.g., running a clad pan through the DW will guarantee it comes out with no seasoning. Likewise the admonition of famous omeleteers never to even *rinse* an aluminum omelet pan.

                  Chefs are more accepting of just wiping out a pan between health code-mandated washings, than is the typical home cook. With the growing popularity of wok cooking and CS pans, hopefully the clean-n-brite obsession with home cooks will moderate some. Our friend Sam F. was more right than wrong about this aspect of a Magic House than he's been given credit for.

                  Aloha,
                  Kaleo

                  1. re: kaleokahu

                    Hi Kaleo,

                    We cross-posted.

                    All good points, several of which I had not considered. I find this point particularly interesting for how it speaks to our conceptions of what is available in the marketplace: "Still another is the dearth of thick, bare aluminum pans." (which, I could have sworn said "copper" the first time I read it)

                    I have a modest local restaurant supply store that I frequent, and I am certain that they do not carry a single stainless, tri-ply, or copper frying pan. They have dozens of different frying pans, but they are all either bare aluminum--the majority of what they have--or non-stick on aluminum. I suppose our collective sense of a "dearth" in this instance is that big-market, higher-end retailers, like SLT, WS, and BB&B have not trotted them out in front of us regularly.

                    I wonder if we'd see a run on bare aluminum if the next WS holiday catalog offered bare frying pans for three digit prices, touting their unrivaled "evenness."

          2. Really its more about the nickel than the chromium with regards to corrosion resistance and inertness. With regards to seasoning, stainless has much much smaller pore size than cast iron and a lot less active sites for any bonding to occur. Most of the stainless that I work with as an R&D chemist in the semi-conductor industry has 8-37% Nickel content and almost no carbon. Low carbon content is probably the biggest reason that carbon (i.e. seasoning) doesn't stick to stainless.

            8 Replies
            1. re: RhonelyInsanediego

              <a lot less active sites for any bonding to occur>

              Agree. Or to put it the other way, whatever active sites have been taken over.

              1. re: RhonelyInsanediego

                18/10 stainless steel (18% chromium, 10% nickel) is the most common steel used in cookware, though a lower nickel steel is used for induction compatible bases.

                I had read that stainless steel gets most of its corrosion resistance from a surface layer of chromium oxide. Assuming it is similar to the aluminum oxide that forms on aluminum, I'm not surprised that both aluminum and stainless steel don't 'season', at least not in the sense of iron or carbon steel. But I haven't read a clear explanation of what is happening when a pan is 'seasoned' (whether it's a physical bonding via surface roughness and pores, or chemical bond or something else).

                  1. re: RhonelyInsanediego

                    Hey, RI:

                    You're a R&D chemist, right? Other than its corrosive effect on aluminum, why wouldn't *graphite* make for a hella nonstick coating, coating ingredient, or seasoning/sealant? It's just an allotrope of the same carbon laid down in seasoning, right?

                    Aloha,
                    Kaleo

                    1. re: kaleokahu

                      Aloha Kaleo,

                      Good question. Several companies do make graphite non-stick coated pans. I just don't think the durability is there.

                      http://www.amazon.com/Graphite-Nonsti...

                      The ultimate best coating would probably be Diamond-like Carbon. This is widely used in high tech industries like mine, but I have never seen it used with any cookware. It is likely prohibitively costly.

                      1. re: RhonelyInsanediego

                        Those look just like regular Teflon nonstick cookware to me. I think the "Graphite" here is the color, not the material. The description is: Seven piece chef's set of graphite-black cookware keeps you cooking and looking good! Sleek pots and pans features non-stick lining for easy cooking and cleanup.!" Other links also suggest that the term may refer to color.

                        http://bestpricecookwaresetnonstick.c...

                        1. re: Chemicalkinetics

                          I think you're correct. The problem I see with graphite is that it is brittle and has little creep making it difficult to adhere properly to a heated metallic substrate. Would probably flake off after time. Whereas with the carbon seasoning on cast iron, it is constantly being consumed and regenerated

                          1. re: RhonelyInsanediego

                            <Whereas with the carbon seasoning on cast iron, it is constantly being consumed and regenerated>

                            I think you are right on the spot. There are already preseasoned cast iron and carbon steel cookware.

                            If a user want to deal with the maintenance of a seasoning surface, then he/she can easily get a cast iron or carbon steel cookware, and will not need pre-disposed graphite. In fact, many people complain about the preseasoning surface from Lodge anyway.

                            If the user does NOT care for the maintenance of a seasoning surface, then whatever graphite disposition on the pan will wear off in weeks if not days.