Finding a good cast iron is probably going to be more challenging than actually using one, contrary to popular belief. Once you go cast iron, all other cook pans will pale in comparison. They stay hot for a while to keep food warm, conduct heat easily, are impossible to dent, provide needed iron for your diet and double as a weapon, what more could you ask for from an object? First off, the texture of the pan will be dependent on the age of the piece. Older cast irons, even well-preserved will be more textured than newer ones, simply because the technology to produce them has changed
(for further information see http://www.anselm.edu/homepage/dbanach/h-carnegie-steel.htm or http://www.saburchill.com/history/chapters/IR/037f.html),
and no matter how hard you scrub, it will never be perfectly smooth, but it will be obviously clean and shiny. If you are picking up a new piece and it’s in rough condition you’ll need to do a little work to get it back up to speed.
First turn it upside down, set on an oven rack and put through the oven self clean cycle to burn off all the bits of grime. Note: you’re oven rack is likely to end up darkened and a little rough, use and old one if possible and if, like me, you use a wood stove, put it in the coals for a bit; keep an eye on it though, so it doesn’t get too hot. Once everything has turned to ash and/or rust, soak in a one to one solution of vinegar and water. Normally you should NEVER put anything acidic in a cast iron (such as tomato sauce) as it will eat the iron, but this process is to help descentigrate the rust, so it’s necessary, but be sure to check on it frequently and don’t let it soak more than four hours. Once all the rust is gone, take the pan out of the solution (gloves are a good idea) and heat again to be sure it’s dry. Use fine grit sandpaper to do any final scouring, rinse and dry again. Final step is to coat the whole pan in a thin sheet of vegetable oil, shortening, or other edible grease and heat the the oven once again at about 275 for about thirty minutes, a process called seasoning(wood stover uses just put back on the top, not the coals, still upside down if you can). This ensures that there is no excess oil and that all the miniscule crevices are evenly coated in oil. After this, your pan should be good to go, though some say you should oil and heat multiple times before use, but it’s up to you.
Now, once you’ve gotten it back to usable condition, maintenance will be easy. I’ve found the best method is a thin, rough sponge. Make sure there is NO SOAP on it, use it only for this purpose, replace regularly. Heat the pan until anything left on it is burnt, remove from heat. Pour in oil or grease- olive, coconut, butter, etc (I have used gristle when I’ve run out of other stuff, but it can be excessive)- and then a coarse salt, scrub in circles vigorously until the pan is smooth and evenly oiled. Scrap all debris into the trash/compost, and wipe the cast iron with a clean towel to get any remaining salt out. Voila’, a new family heirloom!
Whenever you are using your cast iron be sure to add adequate oil/fat to any cooking adventures to help prevent burning and sticking. I’ve found it to be a major issue when making omelets with cheese for instance, the pan gets so hot the cheese can burn on, so I’ve take to adding the cheese after everything else is cooked and using just the residual heat of the pan once it’s off the stove. I’ve also found that a cover makes a world of difference in evenly cooking the food no matter what I’m making, it gives the process an oven like effect and keeps everything moist – we’ve even made cookies and carrot cake this way. Happy frying!