Cast iron skillet care is an important part of getting the most out of your pans.
As we continue to explore options to the traditional non-stick pan we have discussed two common self-seasoning pans that require a different care from non-stick but will give you decades of use: Carbon Steel Pans & Cast Iron Skillets. Over time these pans develop non-stick properties via the seasoning process, the chemistry of which is covered in great detail in this blog from Sheryl Canter. Through continued use a cast iron forms a coating through fat polymerization, its that coating or seasoning we are looking at today. You will find no end of opinions on: who, what, when, where, and why the correct way to season a cast iron skillet. Or for that matter all of the finer point of cast iron skillet care, but from my experience I agree with Sheryl. Flax-seed oil is your best bet for seasoning a cast iron skillet.
As part of normal cast iron skillet care you will from time to time need to re-season it, this allows you to start with a fresh base. This is what I have found to be the most effective process (this is assuming you are starting with a stripped or new cast iron skillet).
Start by warming the pan a low oven to around 180-200 degrees. Place the pan in the oven for 20 minutes to warm it through. This causes expansion and opens up the pores of the metal. From there remove the skillet from the oven wipe out any moisture or remaining residues. With the pan out of the oven raise the temperature to 500+/- degrees while you finish wiping out the pan and begin to grease it. For the greasing process take a tablespoon of flax-seed oil, using a paper towel and your fingers while the pan cools work oil into every nook and cranny in the pan. Wipe out an excess flax-seed oil. Place the cast iron skillet back into the pre-heated oven and let it bake for 45 minutes to an hour. Turn the oven off and let it cool with the skillet inside for a couple hours until you can handle it without burning yourself. If you are starting with a brand new unseasoned pan, or reviving a severely rusted cast iron skillet, it may come out with a matte finish to it, if so repeat the steps above as needed until you get a nice semi-gloss finish.