The Good Folks at Crisco and the Art of Cast-iron Seasoning.
I have purchased my first piece of cast-iron cookware. It's a 12" skillet I paid 3 dollars for at a garage sale the other day (talked the guy down from 5, slick Joe strikes again, heh-heh-heh!). The pan contained what appeared to be fossilized eggs and refried beans, which was my main point of focus during the course of our dickering.
So my odyssey to clean and season the sucker has begun. Cleaning was easy. I scrubbed with steel wool, washed with dish soap, dried with towel, put in oven for the full course of self cleaning, 4 hours. After an hour or so for the pan to cool, I removed it and duplicated the entire process only using 80 grit sandpaper this time. Repeated once more, again using sandpaper.
So now seasoning. Figuring out which method to use has been a thoroughly confusing process. There are more variations on what type of fat/oil/temp/time/number of repetitions than there are prairie dogs in Kansas. That's a lot, believe me. Rather than choose one combination I printed out a list of temperatures, times and oils and employed the time tested, tried and true good 'ol dartboard random selection method. In case you are curious, the winning combo was 450 degrees, filtered bacon grease and 1 hour, 3 applications. After sobering up, I decided that the best approach would be to go to consult with the company that produces the most frequently recommended product.
Thus my phone call to the Crisco questions/comments hotline. Maria was super friendly, very helpful. So, here's the scoop from Crisco: 1 thin layer of regular Crisco shortening (butter flavored apparently will leave an undesirable film and flavor), applied with a paper towel, 200 degrees for 4 to 6 hours. And that's it. 1 application.
It occurred to me while attempting to de-glaze my eyes reading about the scientific processes at work in seasoning that the smoke point was important. Basically, we want the oil to dry but to remain and in so doing produce what is essentialy a shellac on the pan, right? So allowing the lubricant to heat to the point of smoking seems a bad thing. Smoke is the byproduct of the lubricant burning, right? If it burns then some of it is being lost to combustion, floating out and making the house stinky. We're not forging some kind of metal here, we are hoping for a change in the composition of the lube.
There is also the consideration of flavor. After all, this is an implement for preparing food. I have read here and there that coconut oil, for example, will render a subtle flavoring to whatever is cooked in the vessel seasoned with it. Smoke, other than in ribs n' such, doesnt taste very good. This wholly un-scientific line of reasoning leads me to think that the lower temp approach endorsed by Crisco is sound and preferable to the higher temp approach. For what it's worth, the smoke temp of Crisco, according to lovely Maria, is 440 degrees. So 200 is well below the threshold for stinky smoky seasoning.
Now comes the time for decision. I'm going to use the Crisco method. However, I am going to do multiple applications. I'm going to aim for at least 5 and will update my posting with the results. I would like to get the thoughts/comments/suggestions of the highly learned culinary gastro-nauts of chowhound. so waddya say?
To further illustrate my befuddlement regarding the best approach to seasoning, I post here the relevant instructions listed on Lodge Cast Iron's website:
Apply a thin, even coating of MELTED solid vegetable shortening (or cooking oil of your choice) to the cookware (inside and out).
Set oven temperature to 350 – 400 degrees F.
Place cookware upside down on the top rack of the oven.
Bake the cookware for at least one hour. After the hour, turn the oven off and let the cookware cool in the oven.
Okay, we can all agree that lodge is talking about Crisco when they recommend "vegetable shortening", right?
So you would think that the people who manufacture cast iron stuff might perhaps know better than the folks who manufacture "vegetable shortening", but after further contemplation, I think that the Crisco method is better. This lower temp/longer cook time method would seem more likely, in my opinion, to ensure that the oil will harden uniformly and completely. The closer you get to the smoke point the more likely you are to have excitable chemicals, right? So if Lodge thinks that 350-400 is the way to go you have to ask why...
Granted 400 is safely below the declared 440 smoke point of crisco. I wish a chemist could chime in on this. Which of these two official-type methods is better? Is there any difference? Is the speedier approach of Lodge preferable? Is it noteworthy that Lodge and Crisco, unlike the rest of earth, both recommend (explicitly, in the case of Crisco, implicitly for Lodge) only one application? So confused, damn you cast iron!!!
Also, while Crisco is the most commonly available type of vegetable shortening, I'm not sure that Lodge cares whether you use Crisco or any other brand of shortening. I keep other types of shortening around (usually coconut oil based and non-hydrogenated), and they work fine.
In my limited experience, solid fats in general (whether Crisco or not) seem to do a slightly better job for seasoning cast iron and carbon steel. That might be because they have a higher smoking point and / or longer shelf life, might be for some other reason.
I may have posted this question before, so sorry if it's a duplicate- what about mineral oil? One advantage I can think of is that it wouldn't ever get that funky rancid oil smell or the sticky quality that veg/animal fats do, but I know nothing of the burning point, etc- although it's a petroleum byproduct, so theoretically the smoke point is sky-high. Does anybody have real experience with using mineral oil to season cast iron?
I followed the Crisco directions to a T, make a point of wiping off the pan thoroughly to remove any residue whatsoever. After 6 hours at 200 degrees allowed the pan to cool, removed it and.... stickiness. Very frustrating. On a positive note, the coloration darkened uniformly, there is a nice glazed appearance, yet the stickiness is just as uniform. So, back into the oven for another 6 hours at 200, updates to follow.
will47 - I think now you are right about my being wrong, lol. The smoke point is a mixed bag, though. Initially, the only reason I could come up with to avoid exceeding the smoke point was the potential for leaving smoky flavor in the pan.
So I consulted wikipedia regarding "smoke point" and the article states smoke point is the temp at which "a cooking fat or oil begins to break down to glycerol and free fatty acids, and produce bluish smoke. The glycerol is then further broken down to acrolein which is a component of the smoke. It is the presence of the acrolein that causes the smoke to be extremely irritating to the eyes and throat. The smoke point also marks the beginning of both flavor and nutritional degradation."
Now, granted this comes from wikipedia, but I think it might be reliable enough because it's basic scientific principles being addressed and not history or arts or something subjective. It seems that exceeding the smoke point produces first Glycerol, which, despite being hygroscopic meaning it bonds/attracts water, is the component we cast iron people are aiming for. It reduces the coefficient of friction by several orders of magnitude. The smoke, composed of acrolein, is bad news, though. It is a carcinogen and unless it is completely removed you run the risk of leaving a putrid odor/flavor and carcinogen residue on the pan.
I think now I need to go to the smoke point and beyond. I will adjust the oven accordingly and avoid the dreaded acrolein clouds. Update to follow!