I have no dog in this hunt, but thought I would share this video I came across: How To Care For Your Cast Iron Skillet With Science
Interesting. I guess I knew most of it, except that metal utensils are okay and that using soap on a correctly-seasoned iron skillet is okay, too.
Sounds about right. Also, cooking tomatoes and acidic stuff is fine once you get a good seasoning down. There a lot of cooking myths surrounding those things,
Ah, as in the acids in the tomatoes would break down the barrier. Yeah, from the sound of it, a well-seasoned skillet can take a lot. Cool.
Is vegetable oil better than olive oil? Why not season the skillet with the oil I am likely to use most in it?
I’ve never heard that you shouldn’t use metal utensils in cast iron - that’s usually what they say about teflon/non-stick pans. And I’m kind of surprised they didn’t cover the fact that the uninsulated handle will get nearly as hot as the pan, so you should always use a potholder/glove.
I learned very quickly after owning one that you should wipe it dry right away and give it a quick once-over with oil.
But I’ve never understood people who think you need to baby it. It’s a big chunk of iron shaped into a pan. One of the great pluses of cast iron is you can abuse the shit out of it as much as you want and you can still always strip it back down to bare metal and re-season.
There’s a bunch of science out there about the polimerition of oils or something like that, and apparently flax seed oil is the best to use. In my case, it does work a treat and better results than I had with vegetable oil or bacon fat.
It certainly is possible to ruin your seasoning. I’ve done it with metal scrubbing pads or something before and needed to take it back down to the bare metal. Yes, that works, but most people don’t want to strip and re-season something they’ve been working for years on developing.
I knew a lady who thought the seasoning was dirt, so would regularly strip hers back down. Sigh.
I don’t know the science but I’ve had much better results with animal fat like lard or bacon grease than with vegetable oil, though that might be a saturated versus unsaturated thing instead of animal vs vegetable. And olive oil just seems like a bad idea all around. But I’m willing to give the flax oil a try and probably will next time I have to season one of my pans or get a new one.
Because seasoning (forming a protective layer) is a different job from cooking, and an oil that works well for the former doesn’t necessarily work well for the latter, and vice versa.
Yep. Given the comment above dismissing olive oil, it sounds like that applies in this case. Got it.
That reminds me of the scene in Stop! Or My Mom Will Shoot! where the mom decides Sylvester Stallone’s gun is dirty…
Yeah, the article in the OP claims unsaturated fats like vegetable oil work better than saturated fats like lard and bacon, so the opposite of your experience. Although, I have to agree that it at least seemed to me to work better with lard than vegetable oil, too. But when I was using vegetable oil, that was many years back, and I think I was also applying it far too heavily to season (you only need the thinnest coat to season) and when I was using lard, I was wiping it into the pan with a paper towel for the initial season. So, hard to say.
Here’s the article the flaxseed oil suggestions originally came from. (Or at least one of the early articles. Cook’s Illustrated later picked up on it, as well as a bunch of other mainstream press.) Most of what’s out there agrees that the flaxseed oil method works a treat, but I have also found a blog post or two saying they did not notice any measurable difference. From my experience, I’ve gotten much better and much quicker results using flax seed oil, so that’s all I use. You can find it at health food stores or possibly in the health section of a place like Whole Foods or something. It’s not going to be in the cooking oils section. (Actually, looking online it seems that Target stores, at least around here, do carry it in-store, too. It’s just labeled as “flax oil.”)
100 years ago I doubt there was all this debate about what oil to use for seasoning, how to clean the pan, etc. You cooked in it every night and the seasoning naturally built up over time. And that’s still one of the holy grails of thrift shop finds - an old cast iron pan that someone’s grandmother got from her grandmother and has been in constant use for decades.
The other thing about those old cast iron pans is also that they’re milled much more finely (or whatever the proper term is). The bottom of the old pans are as smooth as glass. I have a couple 8-inchers from my wife’s grandmother and they are wonderful to cook on. The newer cast irons have a more gritty bottom surface in comparison. Now, it will season fine, but it seems to take a bit more time and it seems a bit more difficult to get it as non-sticky as the old smooth-bottomed pans. I know some of the more hard-core people will grind and sand them down until they’re as smooth as they can get 'em.
I’m not sure the smoothness is due to the manufacturing process instead of long use. My newer pans started out rough, but after many years of use they’re as smooth as my grandmother’s.
I’ll echo what others have said and say you can’t really mistreat cast iron. Just be aware the surface will change depending on how you use it. My mom regular cooks tomato sauces in hers. It has a different surface than my pans, but it works for her.
I’m pretty sure they were machined differently than today, with extra finishing steps. Here’s an article about it.
Sand casting versus die casting, I believe. Modern cast iron has a pebbled surface that comes from being cast in a sand mold. Older cast iron was cast in a steel mold which gave it a much smoother cooking surface. Some people swear by the pebbly surface, and of course once your seasoning builds up enough it doesn’t matter.
Cast iron from the 1890s or earlier has a mark on the bottom from the mold because that was before they discovered how to inject the iron into the mold at the rim of the pan instead of the bottom. If you find one of those old pans they are worth something so don’t ditch them.
Sounds like you’ve never been to a garage sale with cast iron pans on offer. 
You can eventually get them back into working order, but it can take a bit of work, especially if they’re ravaged by rust.
Well, it looks also like it has to do with the polish grinding final step of many vintage cookware pieces. According to the article linked, they stopped doing that in the 60s due to cost. There’s some pictures at the very bottom of the article, too, if you click. So, it’s not so much the casting process as the finishing.