Cast iron: seasoning, care, and restoration

[Yajna Patni]

Is there a thread somewhere on folk's vintage/antique appliances? I love that stuff! I have quite a bit myself, but live in a teeny apt with a teenier kitchen, so have to put the brakes on a lot. I would love to see collections of those that have more space!

[paulraphael]

... a slightly damped cloth, just damp enough to pick up dry baking soda when you dip the cloth into some which you have placed on a saucer.

Rub the spot or spots, using a clean spot on the cloth and another dip of baking soda when needed.

have you tried this on fully polymerized oils? like on a stainless or aluminum surface? Or worse ... a non-stick one? I've used much more abrasive cleaners on my aluminum griddle ... the polymerized oil seems more abrasion resistant than the aluminum itself.

[andiesenji]

... a slightly damped cloth, just damp enough to pick up dry baking soda when you dip the cloth into some which you have placed on a saucer.

Rub the spot or spots, using a clean spot on the cloth and another dip of baking soda when needed.

have you tried this on fully polymerized oils? like on a stainless or aluminum surface? Or worse ... a non-stick one? I've used much more abrasive cleaners on my aluminum griddle ... the polymerized oil seems more abrasion resistant than the aluminum itself.

←

Yes, I've used it on my All-Clad, on very old Farberware I've owned for 40 years and hardest of all on enameled steel pans like in this photo I originally posted in 2005:

And which I use all the time for "Blasted Chicken" at which time it develops an almost totally black surface, except where the chicken rests.

And this is way it looks today, same pan, only cleaned with plain old baking soda, dry, using a barely damp cloth. I have used this method of cleaning because abrasives ruin the finish on the enamel. I've owned this roasting pan for at least a dozen years and it has seen a lot of oven exposure.

[paulraphael]

And which I use all the time for "Blasted Chicken" at which time it develops an almost totally black surface, except where the chicken rests.

I tried your trick on an aluminum griddle that has thick and thin patches of polymerized oil on it. Didn't make a dent. Seriously ... before and after pictures would show no difference.

I think you're using it on burned on food and juices. Completely different stuff, and not nearly as tenacious.

Also, when I was talking about how hard it is to remove earlier, I meant it as a benefit, not a problem! In the context of cast iron skillets, you want the seasoning to be tough. I was pointing out how it's a lot less fragile than many assume.

Edited April 10, 2009 by paulraphael (log)

[Chris Hennes]

Over on the Cooking Issues blog, Dave Arnold has a short piece up on cast iron. For the most part he confirms what others in this topic have already said, but he does suggest that many thin coats of seasoning are better than a smaller number of thick coats, which I don't think has been mentioned here.

[Dave the Cook]

With all due respect to Dave Arnold (and I have quite a bit), I'm not convinced that he's correct on this point -- or rather, it's not relevant to the point. In fact, I'm not convinced that proper seasoning flakes much if at all, and if it does, it's counterbalanced by the act of cooking. I suspect that flaking is a symptom of weak seasoning. If flaking takes place, thin flakes would be better than thick, but no flaking would be best.

Edited February 22, 2010 by Dave the Cook
clarity (log)

[slkinsey]

The question, I think, is whether it's possible to create a thick layer of polymerized fat-plus-whatever in one go. I would suggest that it isn't. Which is a way of agreeing with Dave about "proper seasoning" but additionally stipulating that it's not possible to create "proper seasoning" in a thick layer.

As for flaking, however, I'm not sure I agree that either Dave is correct. Flaking, in my experience, is due to the accumulation of seasoning into a layer that is too thick to be sustained. Whether the seasoning is an accumulation of 5 layers or 500 layers isn't important. It's the total thickness of the seasoning.

Some of my 100+ year old inherited cast iron cookware shows evidence of flaking on the outside surface where the seasoning has built up quite thickly. The inside, however, shows no evidence of flaking. This is most likely because the seasoning on the cooking surface of the pan has been kept reasonably thin by the scraping of metal utensils, cleaning, etc. whereas there has been nothing to keep the seasoning on the outside surface from getting thicker and thicker over the years until it was finally thick enough to develop cracks and internal faults (perhaps helped along by occasional overheating, etc.) and start to flake off like cast iron eczema.

[jessicahowles]

I was reading slkinsey's tutorial on stovetop cookware and i saw this line - "One word about seasoning and high heat cooking: if the pan gets too hot, it will burn the seasoning and damage it." Does anyone have any idea what is the high heat temperature that he is talking about? More than 400F? (Which i consider really high for browning)

Secondly, I am considering purchasing a cast iron skillet. But I understand it will take a while to heat up the vessel. And I understand that vessels should not be empty for too long else you will damage the cookware. So what do you guys usually do to solve the problem. Put in oil right from the start and then throw in the steak when the oil starts smoking. Or is it the normal searing method where you heat the vessel, wait a few minutes, throw in the oil, wait for it to smoke then throw in the meat. Thanks!

[Dakki]

Not sure what temps the seasoning starts burning at but it's higher than my oven goes. I have damaged the seasoning on a skillet on occasion but only by doing something utterly boneheaded, like putting it on a burner on the highest flame and getting distracted by the phone (or eGullet ).

You can ignore the bit about not heating an empty vessel. It just does not apply here.

Heat your pan dry, put in a bit of oil, wait for the oil to heat up and put in the meat.

[paulraphael]

If you've got a high btu range top, crank the fire, and walk away for several minutes, you can incinerate the seasoning. That's probably the only way it will happen because you'll see and smell a ton of acrid smoke as the coating starts breaking down. Think burning plastic. Seems like it happens somewhere above 500°F.

In normal use it's just not an issue. You can and should preheat the pan for a long time on high heat. Then add the oil and then the food. It's the only way to brown things properly on any pan, especially one with the high thermal mass and low conductivity of a heavy skillet. You'll know you're overdoing if you start coughing.

[tim]

Sheryl Canter has an interesting article on seasoning with flaxseed oil on her blog. Sheryl Canter on Seasoning Cast Iron

The process is quite simple but takes lots of time. Sheryl's method uses food grade flaxseed oil to create a hard, smooth and durable seasoning. Your pans must first stripped of seasoning (oven cleaner or self-cleaning cycle) and dried at 200 degrees for an hour before starting. They are then seasoned with thin coats of oil, 6 times to complete the process.

This looks very promising and should also work on carbon steel.

Tim

[Crouton]

Sheryl Canter has an interesting article on seasoning with flaxseed oil on her blog. Sheryl Canter on Seasoning Cast Iron

The process is quite simple but takes lots of time. Sheryl's method uses food grade flaxseed oil to create a hard, smooth and durable seasoning. Your pans must first stripped of seasoning (oven cleaner or self-cleaning cycle) and dried at 200 degrees for an hour before starting. They are then seasoned with thin coats of oil, 6 times to complete the process.

This looks very promising and should also work on carbon steel.

Tim

This was in the latest issue of Cook's Illustrated as well.... Unfortunately flaxseed oil is pretty expensive

[paulraphael]

A bit off topic, but as an experiment I tried seasoning an aluminum griddle. It's an old, heavy (almost 1/4" thick) aluminum slab with a slight lip. It always orked well but was a pain to clean. So I seasoned with safflower oil in the oven, using the method I outlined above. It took about five coats, and now is gloss-black and fairly stick resistant. Subjectively I'd say the coating is more fragile than the same coating on iron, but it holds up well to spatulas and scouring pads. I don't see any downside.

[Wholemeal Crank]

This is the first time I've seen this topic.

I put together my notes on seasoning cast iron here, but will just share the highlights: ten coats in the oven to go from this

to this

Not hard, just takes a while and be sure you turn off the smoke alarm first!

[toolprincess]

We used cast iron frying pans almost exclusively when I was growing up. I think the only seasoning that my dad did was frying in the pan (bacon, sausage, pork chops, chicken). We always just washed it like the other dishes (we didn't have a dishwasher -- except for me). Scrubbed off any stuck on stuff with steel wool and soapy water. Dried it and the next day started the process over.

[tim]

Hi,

There is a new oil and method for seasoning iron that looks very promising. It utilizes flaxseed oil and was developed by Cheryl Canter.

Shery's Blog on Seasoning

• "It’s a “drying oil”, which means it can transform into a hard, tough film. This doesn’t happen through “drying” in the sense of losing moisture through evaporation. The term is actually a misnomer. The transformation is through a chemical process called “polymerization”.
  The seasoning on cast iron is formed by fat polymerization, fat polymerization is maximized with a drying oil, and flaxseed oil is the only drying oil that’s edible. From that I deduced that flaxseed oil would be the ideal oil for seasoning cast iron."

This is an excellent analysis and offer new insight into a method of developing a much tougher seasoning.

Tim

[Crouton]

Flax seed oil is about $1.00 USD per ounce... not exactly cheap and it lasts about as long as a gallon of milk before going rancid. Seriously, unless you're just looking for something in the kitchen to play with, cooking bacon is much more fun and you even get to eat it

[technophile50]

Has anybody heard of seasoning tin lined copper cookware? I just got a ten piece set of cheap Portugese copper pots from craigslist, and the tin is wearing off.

I have enough experience brazing/welding/soldering that I can retin them myself - and they aren't worth paying more than I've got in them to have it done professionally.

After reading Sheryl Canter's blog, I'm thinking about acid etching the tin lining to provide some "tooth" to anchor a flaxseed oil nonstick seasoning. I did find one online reference that indicated Mauviel tinned copper would build up a "seasoned" layer through use. Plus, a shiny black interior would contrast nicely with the copper exterior! I may just grab some flaxseed oil at my local Weaver Street Market and try it.

[heidih]

Has anybody heard of seasoning tin lined copper cookware? I just got a ten piece set of cheap Portugese copper pots from craigslist, and the tin is wearing off.

The cheap heavy aluminum pans from the restaurant supply store have a tag on them that tells you to season them with oil rubbed on, hated to smoking and excess rubbed off - repeat x3. So seems like an experiment on the tin makes sense.

[patrickamory]

Reviving an old thread.

I just got a 1930s Griswold pan. No rust, totally black and smooth, but unfortunately quite sticky.

I've read the thread thoroughly but I'm confused about the next step. Should I:

- scrub all the seasoning off with steel wool and detergent, and reseason? or

- simply clean it as best I can with soap, water and perhaps salt?

Please advise best next move to deal with stickiness.

[Hassouni]

It might be a massive pain to get all the seasoning off (see below). Try cleaning it off with soap, water and salt and see what happens. If you need to get the seasoning off, put it in the self-cleaning cycle in your oven if you have one, you will be left with bare metal.

This happened to me accidentally, but the seasoning was kind of crummy to begin with so it gave me a chance to redo it. It did get rusty very quickly before I had a chance to re-season, but I soaked it in vinegar for a while and the rust came right off. You must IMMEDIATELY dry the pan off with a towel and put it on the heat, or else it will rust again. Proceed to season as normal. I used olive oil and it's worked great.

[HowardLi]

The most effective seasoning happens once you bring the oil over its smoke point. If you can, do it outdoors since there will be a LOT of smoke when done properly.

[Hassouni]

I do it all in the oven, it's not so bad. I definitely wouldn't do it on the stove though.

[paulraphael]

Shery's Blog on Seasoning

• "It’s a “drying oil”, which means it can transform into a hard, tough film. This doesn’t happen through “drying” in the sense of losing moisture through evaporation. The term is actually a misnomer. The transformation is through a chemical process called “polymerization”.
  The seasoning on cast iron is formed by fat polymerization, fat polymerization is maximized with a drying oil, and flaxseed oil is the only drying oil that’s edible. From that I deduced that flaxseed oil would be the ideal oil for seasoning cast iron."

Any oil that contains unsaturated fats will polymerize. The higher the proportion of unsaturated fat and the more unsaturated, the more efficient the process. You can use lard, which is the old standby, but its low unsaturated oil content means you'll use a lot of it. Anything like canola, sunflower, or safflower oil will work really well and really quickly.

Seasoning is more than polymerization. Polymerized oils are actually very sticky. You need to bring the polymer to the smoke point to carbonize some of the oil. This embeds black carbon in the coating which creates the non-stick properties.

[Kerry Beal]

Flax seed oil is the best I've ever found for seasoning. I throw the cast iron on my Big Green Egg to remove all the old seasoning then set it for for an indirect cook at about 400F for the seasoning phase. All the smells outside.

Here is a great article.

Edited October 25, 2011 by Kerry Beal (log)