I love my cast iron pan, but I really cannot get the perfect sheen that everyone else seems to get. The bottom of mine is non-stick now, and I season regularly, but the sides always seem to chip away eventually. Once the chipping starts, I have no idea how to stop other than to strip it entirely and start again.
There's a lot of answers here, but I don't think anyone said the magic words. To reseason cast iron, you need an oil high in poly-unsaturated fatty acids. Those are the kind that can chain together, and form a good polymer coating.
The thing that trips me up most about this subject is that 140 years ago, pork fat was very good for seasoning cast iron. Today, it isn't, because the composition of the fat has changed significantly.
The best seasoning coats will be thin, not appear or feel oily, give the pan a dark color slightly more glossy than an eggshell, and resist mild detergents, metal spatulas, and heat high enough to sear a steak on. If you have a layer of loose stuff in the pan, that's just a layer of gunk, and is probably adding some weird flavors to anything you cook.
The thing that trips me up most about this subject is that 140 years ago, pork fat was very good for seasoning cast iron. Today, it isn't, because the composition of the fat has changed significantly.
That sounds very interesting! Is it because of the way pigs are raised now compared to back then? They eat way fewer babies now, I bet.
I don't know what causes the difference, I just compared the first nutrition breakdown of rendered pork fat I could find to a recent USDA publication. I'm under the impression that we mostly grow different breeds of pork, on bigger farms, using a more consistent food blend, so pretty much everything has changed in that time.
Don't know of the given info about the pans is correct. But animals nowadays are defintly way more "optimized" than they used to be. Both genetically and the stuff they eat.
To reseason cast iron, you need an oil high in poly-unsaturated fatty acids.
In other words: Linseed.
Though I wouldn't go so far as to say "need". Linseed works much better, builds a nicer patina very quickly, but pretty much any fat works. In practice mine is getting seasoned with olive oil because that's what I have standing around in the kitchen.
Proper technique is much more important in practice: First and foremost heat empty, then add oil and fry, then clean, ideally without degreasing (boiling water and a spatula do wonders), then (if necessary) add a drop of oil and try to rub it off with kitchen tissue, then put back on the stove to dry and maybe polymerise a little. Always have that thin layer of oil otherwise the pan is going to rust.
You can have a perfect patina, if you don't heat up the pan before putting stuff in there things are still going to stick. You can have practically no patina, if you bring up just a single thin layer of any fat up to its smoke point and after that add oil (so the thing isn't completely dry) things aren't going to stick.
Be careful with linseed oil as it spontaneously combusts! My friend used it on something and left the rag in the garage, and it literally burnt their house down.
Not an issue once on the pan: Linseed oil oxidises quite quickly when exposed to air which is where the heat is coming from and it's certainly exposed to air on a pan, however, the pan is also an excellent heatsink and not flammable. Rags are a combination of even more exposure to oxygen (because the oil soaks into fibres and then has lots of surface area) combined with the rag being flammable, those are very specific circumstances. Bottles of the stuff also don't spontaneously combust in the fridge, they only spoil within a week or so (for culinary use, that is, it's still perfectly fine to season pans with it, and is still food-safe. Just starts to taste like ass quite quickly but that doesn't matter when you burn the stuff anyway)
But yes I should probably have mentioned that I flush my kitchen tissues when working with linseed oil.
A good patina will contain a good chunk of burnt oil, it's not that the stuff vanishes when smoke gets produced linseed oil in fact produces very little smoke compared to say canola. Never getting to the smoke point of whatever you have on there will result in a non-black and not entirely unlikely also gooey patina.
It's not a good idea to go miles beyond the smoke point but hovering around it is pretty much optimal. You use oils with higher smoke points if you want a more aggressive sear without ruining the taste of whatever it is you're searing, the thin layer you smoke off when heating the pan, or that smokes off while the pan is cooling off quickly after adding oil+ingredients, is generally so miniscule that it doesn't really affect taste short of giving some wok hei which is generally a good thing. If the smoke alarm goes off or you need to open a window you're overdoing it.
I learned from a chef that an oven would work better due to the even heat applied all over but in a pinch or if you don't want to do all that, the stove top could be fine.
That's the main reason I do an oven seasoning once a year or so. With my electric stove, it'll get the bottom ripping hot while the sides won't ever quite catch up.
In the oven I can do an even, set 450-500 and hold it there as long as I like. Then I can shut it off and let the pan cool slowly and evenly.
Dude, you're not supposed to scrape off the seasoning every time you wash the pan. I reapply a bit of oil maybe once or twice a year. I normally just wash it some soap and water after cooking.
I don't use soap, I just use a bit of hot water with the kitchen faucet sprayer and I have a flat metal spatula to scrape off any stuck on bits... wipe with paper towel and that's it.
That's perfectly fine, I use soap because I eat meat and my gf is vegetarian so I don't want to leave any grease. Also I find soap just makes it a bit easier to clean.
I've got one that I need someone to do this to so I can start over. It's older than I am and was poorly taken care of for several years before I got it.
The cast iron I bought for myself is all in good condition. That one means a lot because of where it comes from but I don't have the patience to scrape all that shit off. I wish someone would do it for me so I could enjoy the pan my grandaddy cooked me bacon in.
My oven uses some weird "eco-friendly" self-cleaning process that involves pouring water into it and steaming the dirt off, which doesn't sound like it would be good for the pan. Got any alternatives? I found a Griswold at the thrift store a few years back and I'd like to be able to restore it without damaging it.
Right, that is your experience. And I'm telling you that there are cast iron fry pans that can defeat wire brushes, both manual and ones you attach to your power drill. (Of course it's up to you if you want to believe me. There's no particular reason to believe some random stranger online, but then again, there's no obvious benefit for me to lie about it.)
Wet/dry sandpaper is fast and will easily get you down to the fresh bare metal again. Then you simply re-season and start cooking that delicious bacon in it again. A rainy Saturday afternoon will easily get it done.
coat that sucker with avocado oil and bring it up to 200°C for a few minutes. Allow it to cool, repeat until the sides don't hold any oil, then switch to crisco solid shortening for a few rounds.
You can use various different food oils, the important part is that it can leave a (food safe) polymerized coat that binds to the surface, protecting it from rusting as well as making it non-stick
In addition to what the other person said, olive avocado oil has a high smoke point, meaning it has to get pretty darn hot before it creates smoke. It handles heat a lot better than other oils.
