TAKING CARE OF CAST IRON
Routine Maintenance
If you buy a preseasoned pan (and you should), you can use the pan with little fuss.
Don't wash the pan with soap or leave it in the sink to soak. Rinse it out under hot running water, scrubbing with a brush to remove traces of food. (This is easiest if done while the pan is still warm.)
Dry the pan thoroughly and put it back on the burner on low heat until all traces of moisture disappear (this keeps rusting at bay). Put a few drops of vegetable oil in the warm, dry pan and wipe the interior with a wad of paper towels until it is lightly covered with oil. Then, using fresh paper towels, rub more firmly to burnish the surface and remove all excess oil. The pan shouldn't look or feel oily to the touch. Turn off the heat and allow the pan to cool before putting it away.
Heavy-Duty Cleaning
If you have stuck-on food or you've inherited a pan that is rusty or gummy, scrub it with kosher salt.
Pour in vegetable oil to a depth of 1/4 inch, then place the pan on a stove set to medium-low for 5 minutes. Remove pan from heat and add 1/4 cup kosher salt. Using potholder to grip hot handle, use thick cushion of paper towels to scrub pan. Warm oil will loosen food or rust, and kosher salt will have abrading effect. Rinse pan under hot running water, dry well, and repeat, if necessary.
Reseasoning
If cooking acidic foods or improper cleaning has removed the seasoning from your pan, it will look dull, patchy, and dry instead of a smooth, rich black. You need to restore the seasoning. We have found this stovetop method (rather than the usual oven method) to be the most effective way to season a cast-iron pan.
Heat pan over medium-high heat until drop of water evaporates on contact. Wipe inside with wad of paper towels dipped in vegetable oil (hold towels with tongs to protect yourself). Wipe out excess oil and repeat as needed until pan is slick.
CAST IRON HISTORY
Cast-iron cookware is formed by pouring molten iron into a mold made of sand, which is used only once, making each pan unique. The process originated in China in the 6th century B.C. and has been mostly unchanged for centuries, with the exception of machines that now pour the hot metal into the molds. Cast iron was the material of choice for cookware in America until the early 20th century, when aluminum became affordable. At one time, there were dozens of American companies making cast-iron cookware. Today, there are just two, Lodge and American Culinary (which sells pans under the Wagner label). Most of the pans we tested are made in China.