Washing & caring for Cast Iron after you’ve seasoned it:
CAUTION: NEVER put cold water in a hot pan! – it could warp or crack it.
Let it cool for a few minutes after cooking. Run the water in the tap until it is hot (or have a small pot of boiling water ready) then introduce it to the warm pan. DO NOT use any soap or detergent to clean it - that will degrade the seasoning and leave an unsavory residue. Soap should never be used to clean a seasoned pan because it will dissolve the formed protective barrier and embed itself into the pores of the metal where it will return to taint your next meal.
Put about 1 inch or so of hot water in the pan, just bring it to a simmer, then turn off heat. Let the pan soak for 8 to 10 min, dump out water and rinse with more hot water, then wipe it out with paper towels. If there are stubborn food residues use a clean plastic scouring pad (scrubbie) to scour the pan with warm water. Dry it carefully by placing over low heat for a minute.
Right before using it again wipe a little Crisco or spray a light coat of Pam on the cooking surface. Wipe off with a paper towel. This cleans and prepares the surface. Now add whatever fat or oil you are going to use for cooking.
Never start heating a cast iron pan on high! This can cause a hot spot and permanently warp the pan. Pre-heat with medium-low heat for a couple minutes. Or place the pan in your oven and set it at 350 degrees and let it preheat for 8 – 10 min. This is the best method for larger skillets (#10 and larger) and Dutch ovens. Then you can put it on the range burner and turn it up to medium-high (if you are searing meat.)
Use a stainless steel spatula (not chrome-plated steel) with a perfectly flat, smooth edge and rounded corners so as not to scratch the nice black layer you have made. A well-used one is ideal as it has its edges smoothed and rounded from use. Check those garage sales and thrift stores for one! If your spatula’s edge is not smooth use the fine side of a flat sharpening stone to hone the edge and remove any burr.
You can use soap to clean a cast iron pan, but usually only when you do not plan to use it for awhile. The oils and fats in a cast iron pan have a different molecular structure than prior to cooking. This allows them to go bad after some time of not being used. That is essentially how the pan is being "seasoned". When you heat oil to certain temp and break down the molecular structure to just carbon atoms. When not broke down all the way you get an unbalanced molecule. So, I wash my pans with real hot water and a stiff, plastic bristle brush unless storing them for over a month or two. I do not use a lot of soap just enough to get the surface oils and fats off, then rinse real good, and heat it on the stove to dry it off and open the pours of the pan, add a little oil and wipe around to replenish the pan, let it cool, then wipe out the extra oil. There is an article at http://www.thecampden.com on how to clean and maintain your cast iron cookware, there is also a good variety of cast iron cookware to choose from.
One weekend my friends and I got up to NH to stay at that friend's long time family cabin. Besides being something of an edge freak, I also like things that go bang. As did the friends I was with. We had some bang things, So somewhere later, alot, that night, we found an old 14 inch cast iron skillet, not in the kitchen but like in the shed, rusted old nasty thing.
For the short of it, that old tree stump that had been used for years as a sorta outside chopping board was the launch pad, a serious M-80 bang thingie, well the skillet just looked like a good noise supresser on top. Probably got about 25 ft straight up on first bang. Cooked breakfast eggs on it next day, had a slight belly dent.