In recent years, there has been something of a cast iron revival. If you go online and read anywhere, you’ll see lots of recommendations for cast iron cookware on many websites for many diets. Many will emphasize the advantages that cast iron has over other types of cookware. Typically it is presented as a better, more natural alternative to non-stick pans that use a Teflon coating (PTFE or Polytetrafluoroethylene).
For the most part, I have given it up because there are some very significant drawbacks that are seldom emphasized. You’ll see the emphasis especially in some of the “traditional” diets. I’m a big fan of Paleo 2 and Weston Price, but I must disagree with their advice on cast iron.
Why is there so much cast iron advocacy?
Cast iron saw a revival due the concerns that people had about non-stick pans, particularly with aluminum and PTFE. Others simply seem to want to return to the “good old days”. A cast iron pot is basically a pan made of close to pure iron. It is manufactured by pouring molten iron onto casts to shape it. It is then machined into shape to form the end result.
There is also a noteworthy market for collecting vintage cast iron cookware. A few well known brands that are out of business:
- Griswold: Probably the most well known of the vintage cast iron cookware. They made several lines of products, including under the Erie line. See here for details. Sadly they have been out of business for many years now.
- Wagner: Also very well known. My experiences have been that they make thick and good quality cookware. They were also sold under Sidney. Again, it’s more complicated. See here.
A few brands that exist today (there are so many so I’m not going to go on):
- Lodge: They have a “rough” finish, but they are very thick and quite affordable. I believe that they are the only American company still in the business of making cast iron cookware.
- Iwachu: A Japanese brand that I have only limited experience with. The finish is good quality though. They are owned by N&I Asia.
- Staub: They make very good quality enameled cast iron cookware, although very expensive. I believe that Costco currently uses this brand as the OEM, although many claim that the Costco enameled cast iron is not the same quality, which would explain the price difference. Zwilling J.A.Henckels is the parent company.
- La Creuset: Well known French brand for its enameled cast iron cookware; again quite pricey. Compared to Staub they do have a smoother finish, but on Staub the lids fit better, are metal (so can take higher temperatures), and the lid features made it easier to use. You won’t know unless you see both which you like better. Between the two, I personally consider Staub to have the superior product, even if La Creuset is the better known here in North America.
Again this is not intended to be a complete list. If you think there are brands that need to be added, please leave a comment below.
A bit about non-stick cookware first
One thing we may want to explore first is why are the so-called “non-stick pans” so bad? PTFE should be inert under normal circumstances, being a fluoroplastic, which are known for their chemical stability, heat resistance, electrical resistance, and resistant to chemical solvents. However at the temperatures that you see in cooking (especially if you turn the heat above medium), the risk of the Teflon coating causing problems becomes a potential health problem. Out-gassing can be an issue, as the PTFE could react to form gasses such as Hydrofluoric Acid. If you’ve owned a non-stick pan, you’ll notice that over time, the non-stick coating tends to come off. That’s because most of it has been scrapped off. Most of the PTFE should pass through your body as it is chemically stable and be excreted out, but what does react could react to form some pretty unpleasant chemicals. Anyways, it has been hypothesized that these can lead to various health problems over time. Perfluorooctanoic Acid (PFOA) and Perfluorooctane Sulfonate (PFOS) are two examples of chemicals that can form, which have been linked to cancers.
There is also the matter of cooking with aluminum cookware. You do consume a bit of aluminum each time. I do not recommend cooking with aluminum as a small amount gets absorbed into the body, especially with leafy grains and acidic foods, or perhaps if you scrape it with sharp utensils. Aluminum is promoted because it is a lightweight metal with excellent heat conduction and a high specific heat capacity relative to its mass. Anodized aluminum (which is basic a where the aluminum is put into an acid bath with an electric current) deposits a thin layer of aluminum oxide to make it scratch and corrosion resistant mitigates, but doesn’t solve the problem of scratches and damage. My big worry though is chronic, long-term exposure to moderate amounts of aluminum, which could lead to long-term health problems.
It makes cooking “easy” in that the non-stick pan makes cleaning easy, while the lightweight pan makes it easy to cook with too, which is why it was promoted, but it seems to have some very unpleasant long term costs. Basically this is why I don’t use non-stick cookware.
Enough of that – why is cast iron promoted?
Cast iron has been promoted as an alternative to mitigate these flaws.
- It does not have the unpleasant chemical leeching of PTFE nor would a cast iron pan contain more than trace amounts of aluminum.
- Cast iron cookware is usually pretty cheap and easy to find (you can find some old vintage ones on eBay, Kijiji or at a local yard sale). That said, enameled cast iron (with good quality enamel anyways) can be expensive.
- Very high heat capacity: Due to the sheer mass of cast iron (after all it is a solid piece of iron), there is a lot of heat stored in the pan itself. So when you put a piece of cold meat or something else on, the temperature does not immediately drop due to the high heat within the pan. Cast iron is usually thick, which is why there is a lot of heat capacity. Note though that this advantage does not apply to thinner carbon steel cookware.
- Works on induction because it’s pure iron (therefore magnetic). You can also put it into the oven at high temperatures. It is solid iron so it is not going to be damaged by cooking temperatures.
- Subjectively, many people claim their food tastes better with cast iron. This may be due to the iron leeching or perhaps because they are eating a bit of the fat from the seasoning.
Obviously these are some pretty big advantages, so why would I give up cast iron?
What are the drawbacks of cast iron?
From my experiences, many websites pushing for cast iron often don’t emphasize its drawbacks. They were enough for me to give up cast iron.
These are my experiences back when I worked with cast iron cookware.
One of the first things that you will notice about cast iron is how heavy the cookware is. On one hand, that is why there is such good heat retention. On the other, a heavy pan of course is difficult to work with and could be a safety issue. Be careful about using it on a high shelf or when moving the pan with heat. Remember what I will note below about the handles being hot when the pan is cooking. While I don’t view this as a big drawback because you need mass for good heat retention, it is something to be aware of.
I will however note that iron does not have a good specific heat capacity versus mass, which is why a lighter mass pan is possible, but with its own benefits. Due to this mass, you should be aware that cast iron takes a while to heat up. That is to say, when you turn up the temperature or turn it down when cooking, it will take a bit for the cast iron pan to respond. Be especially careful with high temperatures. You could end up with a grease fire. If that happens, cover the grease fire (thereby depriving the fire of oxygen) and turn down the temperature. Never put water on a grease fire! I recommend against using higher than medium in most cases for that reason.
When you think of steel, what do you think? Usually pretty tough. That is because steel is an alloy of many metals, combining them to give a desirable property. I am simplifying, but that’s the basic idea. Pure iron is actually surprisingly quite brittle. Next, hold up a cast iron pan. It feels satisfyingly solid in your hand and of good quality. You are probably thinking that a thick iron pan like that would not break and more or less, survive anything. You can actually damage cast iron by banging it against surfaces if the impact is very hard.
Also, if you do use cast iron, be careful about the temperature. Don’t change the temperature of cast iron cookware very rapidly or you could damage the cookware. You could actually crack the cast iron!
You must season
One big drawback of iron is that it is very prone to rust. Stainless steel is more expensive because it is far more rust resistant. I recommend scraping off any pan that was bought from the store that was “pre seasoned” as they often use something non-edible, like linseed oil.
To that end, you must season your cast iron cookware. Which oil to choose? Sheryl Canter has an excellent post about this. She recommends using a drying oil – flaxseed oil was her recommendation. The reason why is because flaxseed oil is the only edible drying oil. Seasoning occurs when fat polymerizes. Make sure that you buy pure flaxseed oil as some of the comments in her post indicate less than stellar results with other types of oil. Barleans Flax Oil was the brand that Canter recommends as it is pure.
Canter also recommends trying to create magnetite onto the pan to protect it from rust. Read her post for more details.
I’m not going to go too in depth into seasoning (it’s worthy of a post on its own), but the point is that you must season. Cast iron pans take a long time to season. You have to strip off the old oil, then heat the pan slightly. Then you have to apply the flaxseed oil onto the pan and then heat it to past smoke point (probably in an oven). This will have to be repeated with 5-6 thin coats (don’t use 2-3 thick coats to speed this up). This whole process easily takes a day and many with multiple cast iron pieces of cookware.
That brings me to a safety concern, which is the consumption of free radicals from the seasoning. Seasoning must contain a lot of polyunsaturated fat that was exposed to high temperatures. That’s part of how the seasoning process works. The problem is that seasoning can flake off (and it often does), which means that you eat a bit. I haven’t seen any studies about this, but my “gut feeling” if you will is that this is not a good thing.
Must use frequently, but the iron leeches
Iron rusts, as indicated, and over time, the seasoning gets better because as you cook, you are essentially turning the layers of fat into something that will protect the iron from rust. For maximum benefit, you have to frequently cook with your cast iron pan.
I don’t consider the fact that cast iron leeches iron into the food to be a benefit. With the exception of people with anemia, most people do not have an iron deficiency on a typical Western diet. In fact, it has been suspected that we may even have too much iron. It’s been hypothesized that depletion of iron stores is one reason why blood donation is good for life expectancy. Likewise, the fact that women menstruate (and lose iron) has been hypothesized to be a reason why women live a few years longer then men usually do.
Although true that in many cases, food does taste better with cast iron, you can get some strange (and in this author’s opinion unpleasant) flavors when the iron leeches into the pan. This is another reason why i recommend against using cast iron with anything acidic.
One other thing – do not use any detergents when cleaning your cast iron pan! It will strip the seasoning and you will have to re-season.
Uneven heating – not entirely non-stick
Around the web, you’ll see claims that cast iron with seasoning is very easy to work with and that it leads to very even heat conduction. This is one of those cases where you cannot believe everything that you read. Some say it is as easy as PTFE! It is not like that at all in practice, at least from my experiences. Even a well seasoned skillet is not as easy to maintain as PTFE. I’d consider it to be “half non-stick”.
Iron is not a good conductor of heat. The problem is that this leads to very uneven heating, especially on small ranges. You often get “hot spots”, where one area is burnt and one undercooked. The burnt area can leave marks on even well seasoned cast iron that makes it tough to remove.
You could also experiment with an infrared camera. If you were to look at the temperate differential between the centre of a cast iron pan and the outer edge, with a cast iron pan, you are looking at perhaps 50C and at higher settings, perhaps more than 100C. That will lead to very uneven cooking. Aluminum skillets will be much cooler (likely under 30C) and copper even better (perhaps even under 15C). The thicker the disk, the better the conductivity. Compared to other cookware, cast iron does very poor job of conducting heat to the outer areas of the pan. You will need to constantly stir to mitigate this and move your food around for solid pieces.
I should also mention that one of the reasons why cast iron pots are cheap is because they are cheaply made and you will find imperfections. These small imperfections can lead to localized “hot spots” that can lead to burnt food and after you are finished, can be difficult to clean. The rough finish of many cast iron pans can also worsen this problem. One of the reasons why Griswold and Wagner are valued because of the smooth finish compared to Lodge and more modern cast iron cookware. You can tell because the quality of the machining is generally superior, although I find that modern high end cast iron sets do match them.
The best way around this that I have seen is to first preheat the even, then put in the cast iron pot to a moderate temperature. A little bit before you take out the pan, turn the heat on the range to medium on the burner that you wish to use. Then take out the pan and add oil. Provided the oil is hot enough, add the food. This also addresses the problem of preventing grease fires.
Be careful with the handles when cooking
Another safety matter, but something you should be aware of. The handles are hot! It is not like stainless steel handles. Do not touch the handle when cooking unless you have something to protect your hand. The handle will be very hot. Oven mittens also work quite well. Many brands of cast iron pans offer handle holders. Pick what works for you – just don’t touch the handles when food is cooking.
Also, many brands do seem to offer insulated handles. They vary in quality. One thing I will note is to be careful about high temperature cooking or putting the cast pan in an oven with these handles unless you are sure that the handle can stand up to the high temperatures. Overall, I prefer my pan handles to not be insulated and to use oven mitts, unless I’m sure that they can take very high temperatures.
Enameled cast iron
The drawbacks of cast iron have led to enameled cast iron. This prevents leeching and rusting. You only need to season the rim and some advertise not even that if the rim is covered. Probably the best known brands are Staub and Le Creuset. They are expensive. My advice with enameled cast iron is to research carefully, because they are much more expensive. Staub is my personal favorite for these, but it is expensive.
One big benefit is that you can store salty or acidic foods in enameled cookware. The reason is that the enamel should protect the metal from any corrosion or any other effects. Normally with other metal cookware, that is a big “no”, but the enamel is what the food is in contact with.
The problem with enamel is that over time the enamel can chip or crack. That’s especially true with the low quality enamel you see on cheaper pots. Remember how I said cast iron was brittle? Well enamel is very brittle. Enamel can easily chip, scratch, or even with care, wear over time. Like cast iron it is very temperature sensitive.
Some other thoughts
Acidic foods should not be cooked in cast iron. I am talking about foods like tomato paste, cooked fermented foods, and the like. If you do so, clean the pot immediately after cooking (don’t wait – do it as soon as it’s cool!) and then apply a fresh layer of oil. You may need to re-season.
The shape of cast iron also makes it energy inefficient. That’s because the metal takes a long time to heat up and there is no retention.
I will also put together a list of situations that I think where cast iron is especially bad.
- Anything that is very sensitive to being burned: Milk based products, custards come to mind off the top of my head. Meat that does not have a lot of fat (which acts as an insulating layer) could be an issue as well, unless you are very skilled with cast iron. Cast iron is good for fattier cuts of meat, but anything lean should be cooked with something else.
- Where you need fine temperature control: If you want avoid browning food or anything that you need very careful control (like for making sauces). I’d recommend a sautese for making sauces, and something thinner for temperature control. Sauces especially can be burned, which ruins the taste.
- If it is essential that you need the entire area evenly cooked. Look for cookware that has a large aluminum base or copper cookware.
- Acidic foods: As indicated previously, this can hurt the cast iron and over time, cause corrosion. So no tomato pastes in cast iron nor highly fermented foods.
- I do not recommend using cast iron for boiling or simmering water for long periods of time. It could strip off the seasoning.
So even if you use cast iron, I’d recommend that you not use it for these types of dishes.
As you can see, that’s a pretty big list of situations where cast iron will not do well and a pretty big list of drawbacks.
So what do I use now?
You might think that I actually “hate” cast iron. That’s not true. I actually encourage you to go out and buy an inexpensive cast iron skillet to try out much like the one pictured. They are not expensive and you might learn quite a bit about cooking with cast iron, both the benefits and the drawbacks. You may even find that with the downsides, cast iron is actually for you and that you can work with it! I think though that you should be aware of the very substantial drawbacks that cast iron has. If you are prepared to live with the drawbacks, cast iron can be one of many pieces of cookware in your set.
To me the advantages were outweighed by the considerable drawbacks that cast iron had. It is very time intensive, it does not heat evenly, and it has its own idiosyncratic issues. Looking back, I think I understand why stainless and aluminum must have taken over.
At the moment, I use the Demeyere Proline skillets for frying. They are available in several sizes, but I think the 24cm and 32cm variants are the best sizes right now. They are not cheap, but they have all of the advantages of the cast iron cookware and some advantages of their own. I will explore this in a later post. For acidic foods, I recommend using ceramic cookware. You could also use the enameled cookware i described above for such tasks, although as indicated, I personally have stopped using cast iron cookware. I do not recommend using ceramic for everything though as over time, I find ceramic loses its nonstick properties.
That was my first cooking article. I plan on making a few more in the future.