Carbon Steel vs. Cast Iron frying pans/skillets

What is carbon steel?  It is essentially the same thing as cast iron, except perhaps not as brittle as cast iron, and unarguably MUCH thinner and lighter than cast iron!

“Most types of steel have a relatively low carbon content of about 0.05% to 0.3%. In comparison, carbon steel has a carbon content of up to 2.5%. Two-and-a-half percent carbon may sound insignificant, but it introduces several attractive benefits that aren’t found elsewhere.” – Monroe

“Steels containing only carbon as the specific alloying element are know as carbon steels.  These steels can also contain up to 1.2% manganese and 0.4% silicon. Residual elements such as nickel, chromium, aluminium, molybdenum and copper, which are unavoidably retained from raw materials, may be present in small quantities, in addition to ‘impurities’ such as phosphorous and sulphur.“

I don’t know if it’s true or not.  I wonder how many ‘residual elements’ are found in cast iron or stainless steel cookware.  Manganese and Silica seem like harmless ingredients though, if anything ‘mined’ can be described as harmless…  Plus, compared with stainless steel, which can have between 16% -25% chromium, it just seems so much better…

In a post by Tamara Rubin in which she tested the metals in a carbon steel Morakniv Swedish carving knife, she found the following metals:

• Chromium (Cr): 2,094 +/- 301 ppm
• Iron (Fe): 991,300 +/- 1,800 ppm
• Magnesium (Mn): 4,103 +/- 585 ppm

From the looks of this knife in the product page, it seems as though it has a shiny finish, unlike plain old carbon steel.  Likely the added chromium is what gives it the ability to be rust resistant. So, even though it is advertised as “carbon steel,” doesn’t mean it doesn’t have added ingredients, such as chromium.

To give added perspective, these Shun kitchen scissors (DM7240) are made of ”

High-carbon, molybdenum-vanadium stainless steel”

so the steel used in these scissors is at least 10.5% chromium by mass, which makes them resistant to rust.  Molybdenum boosts the rust-free properties of the steel and added vanadium strengthens it.  Because of the added molybdenum and chromium, they won’t stay as sharp is true carbon steel scissors, such as these sold by Tanegashima Hamono, which are described as made of “shirogami #1 steel, with minimum impurities.”

So, I think the lesson here is read the descriptions carefully.  Is it described as plain carbon steel, or are there other metals in the description?  Does the steel look shiny, like stainless steel?  Does the product description warn against letting the item stay wet (rust) ?  True carbon steel will rust, so the item must be dried to prevent this.

Home cooks and professional chefs have been using carbon steel cookware for a long time!!   I think I even see a few carbon steel pans among the many hanging from her famous pegboard organized kitchen equipment wall, now in a museum.

Use in the United States

Well known French carbon steel cookware brand De Buyer has been making carbon steel pans since the early 1800s, and they are still making and selling carbon steel kitchen items today.  Unfortunately, their frying pan has tested positive for lead on the inside of the pan!

My best guess is that they never became popular for various reasons as people continued to use cast iron, and as Teflon non-stick cookware became popular in the 1960s and on, people left their carbon steel pans and baking sheets behind, if they had ever had them.  We are often fickle, leaving behind wonderful ideas in pursuit of exciting shiny new objects. 😉

Although I don’t know ANYONE that uses carbon steel in their home kitchen, I have seen carbon steel pans in use in various restaurant kitchens, although I didn’t know what they were when I first saw them!

Is Carbon Steel Healthy or Non Toxic?

Although iron can leach into food from iron cookware, I still feel more comfortable with ingesting iron than potentially ingesting nickel and other metals used to make stainless steel alloys used to make stainless steel cookware.  Read more about iron leaching from cast iron and carbon steel cookware in this post.  De Buyer frying pan has been tested positive for lead on the INSIDE of the pan, but I don’t know if other carbon steel brands will test positive as well.

The beauty of carbon steel cookware is really its light weight, as well as its non-stick nature.  Since it is literally made out of steel and nothing else, I feel comfortable using it regardless of how many scratches it sustains over many years.  It’s nice to know that although pans may become scratched, they are still relatively non-toxic.  I may convinced otherwise if I learnt more about stainless steel pans and how they are constructed, but I worry that as they sustain scratches, the various metals used in the alloy are exposed, such as nickel, and can be ingested.

However, carbon steel pans rust really quickly.  For that reason, they are not practical in my kitchen.

What makes them non-stick?

I don’t know that I can answer this in a scientific way, but I suppose the short answer would be the method used to texture or rather, smooth! the cooking surface.   All carbon steel pans have a smooth surface, but not all cast iron pans do.

If you’ve ever used a vintage cast iron pan like a Griswold or Iron Mountain, you know that the cooking surfaces of the cast iron pan is very smooth, and if maintained well, almost glassy in appearance.  Modern ‘economy’ cast iron brands such as Lodge do not have a similarly smooth surface.  Rather, the Lodge cooking surface is rough or ‘pebbly’ to the touch.  Here are some pictures from the ‘The Pan-Handler’ blog to demonstrate:

Why the difference?  The smoothness of the cast iron or carbon steel cooking surface is achieved (or not achieved) through various smoothing or polishing methods.   I don’t know what methods were used to create the smooth surfaces seen in antique or vintage cast iron pans, but modern cast iron manufacturers like Butter Pat Industries, Field Company, Stargazer, and Smithey use a variety of methods and materials – some which they will share, and some which they won’t, citing ‘trade secrets.’

Some of the methods include sandblasting and polishing and machining and sanding.  I’ve found that carbon steel pans are often created using similar methods.  The most popular material used in sandblasting seem to be aluminum, because it is cheap and widely available; however, other materials can be, and are used in these manufacturing processes, such as steel, quartz sand, glass, garnet, and wire brushes.  I’m not sure what the cutting or abrasive material is used when machining a pan.  I’m assuming that when you find a vintage cast iron pan that has been machined, you will see a ton of very closely spaced coecentric circles, or maybe a spiral? in the pans cooking surface.

I don’t know for sure, but would guess that the terms used to describe these two types of iron cookware tell us something about how they’re made, and what types of methods of materials would be required to obtain a smooth surface.  The term ‘cast iron’ seems to tell us that the iron is cast, in a mold, I would imagine.

Whereas carbon steel pans seem to conjure images of blacksmithing and hammering.

I gather from watching these two videos that since the cast iron pans are cast (often in) sand molds, that a pebbly surface would result, due to the texture of the sand, thus, resulting in a more rough surface than what might result in the carbon steel process.  Thus, machining would be required.   I imagine that tool bits are used, perhaps made out of hard ceramic, that must be replaced from time to time.  Rotating files made with hardened steel may be used, as well as rotating files made of diamond.

Where Carbon Steel Shines

It seems that in the wake of the government (EPA) ban on Teflon in 2015, I think more and more of us are becoming aware of how toxic chemical non-stick cookware is, and are looking for alternatives.  Cast iron pans are fun and nostalgic, and I’ve used them for many years, but sometimes, it can be really tiring and difficult to use in the kitchen, due to the weight and griminess and bulk.

I was really happy to finally discover carbon steel pans and what they can offer in the kitchen.  They are extremely light weight, and therefore easier to transport around the kitchen and maneuver in the sink while washing.  They need to acquire and maintain a layer of seasoning (essentially baked on, or polymerized oil or fat), just as cast iron pans do, but I don’t find this difficult to achieve.  Due to this layer of seasoning, they are incredibly and luxuriously not sticky – the food does not stick, as you can see in the video below, of an egg sliding around like butta in a Matfer Bourgeat carbon steel pan.

Quality, Weights, Brands

Matfer Bourgeat brand pans…do they have lead, like De Buyer?  I don’t know.  Someone should buy one of their pans and send it to Tamara Rubin for testing.

There are a variety of thicknesses and weights offered in the carbon steel market.

Carbon steel is generally much lighter than cast iron, but check your weights…some brands are lighter than others.  I’m not sure if weight = quality, or if there is a different metric….  Not all brands offered a 10″ pan, but I tried to choose the closest size for comparison:

To see a list of weights and prices for carbon steel, visit this link.

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Here’s the breakdown in writing, in order of lightest to heaviest for cast iron:

• Marquette Castings 10” 3.7 lbs, 8” 2.5 lbs – China-made line.  While lighter than their USA-made line shown below, the surfaces aren’t as smooth as the USA-made line.  I haven’t seen any reviews on the surface smoothness of either their China or USA-made lines.
• Field Company 10.25″ pan 4.5 lbs., or 11.5″ pan 6 lbs., good cooking surface as well and comfortable handle.  doesn’t have pour spout and may not pour well.
• Butter Pat 10″ 4.8 lbs, or 12″ 6.9 lbs, best cooking surface, the bottom of the handle might get uncomfortable, has pour spout.
• Stargazer 10.5″ 5.2 lbs., smooth surface, but handle might be uncomfortable for smaller hands.  pour well from any angle.  Confirmed lead-free.
• Smithey 10″ pan at 6 lbs – their pans have a heat ring on the bottom.  has pour spout.
• Borough Furnace 10.5″ pan 6.3 lbs, 9″ pan 5 lbs.
• Marquette Castings 10.5” 5.2, 13” 7.6 lbs.  While heavier than their China-made line, the surfaces are a bit smoother.
• SolidTeknics – update 2/13/18: the company has said that they have retired their cast iron production due to manufacturing challenges in Australia.  Find out more about cast iron brands here.

Environmental Impact

Sandblasting and/or polishing process – almost every company uses aluminum to sand blast the surfaces of the pans.  Blu Skillet Ironware is the only company (cast iron or carbon steel) that does not use aluminum – they use non toxic materials such as quartz sand and other alternatives.

Carbon Steel – who uses aluminum during manufacturing?

• Blu Skillet Ironware, NO aluminum used!  verified 3/28/18
• Blanc Creatives, yes aluminum used in sandblasting, verified 2/15/18
• Matfer Bourgeout – pending verification
• Mauviel – pending verification
• SolidTeknics – pending verification (update 03/2018: they won’t release any manufacturing information until after their patents are completed).

Cast Iron – who uses aluminum during manufacturing?

• Butter Pat, yes aluminum used, verified 4/3/18, Butter Pat Industries – “aluminum oxide early in our process followed by glass beading and walnut shells. We still use some aluminum oxide but continue to research ways to eliminate it completely from our steps. Unfortunately it is ubiquitous. We do no printing on our boxes for similar reasons and only include collateral using plant based inks – but again this raises costs.”
• Field Company, yes aluminum used, verified 2/19/18
• Stargazer, yes aluminum used, verified 3/28/18
• Smithey, they don’t sandblast; however, they use fine grit sandpaper consisting of aluminum (as the abrasive).
• Skeppshult – pending verification
• as the core of the pot or pan – some companies such as Staub make cast iron pots that are actually not 100% cast iron.  Rather, they consist of an aluminum core which is then covered with cast iron.  Most pots and pans contain aluminum or copper cores to better conduct heat, but is it worth it?  My 100% cast iron pots and pans work just fine….  This is placed in the secondary category; however, if one were to wear through the cast iron finish, one would ingest and be directly harmed by the aluminum.

How to Maintain Carbon Steel Cookware