When it comes to cleaning cast iron, there is one commandment: Respect the finish. Hot water is the best tool, combined with a gentle scrub with a sponge or paper towel. Avoid immersing your cast-iron cookware in water, which increases the risk of rusting.
If you’re stuck with stubborn bits of cooked-on food, add about 1⁄4 cup kosher salt to the warm pan, and gently scour with a folded kitchen towel or the cut side of a potato. Rinse, and dry thoroughly.
Never put your cookware away dirty. Excess oil will pool and solidify, making future cleaning difficult. For best results, clean pots and pans immediately
Drying Cast Iron
After rinsing, it’s crucial to dry your cookware completely. Wipe dry with a clean dish towel or paper towel, then apply a thin coat of oil, rubbing it into the surface. Heat on the stove over medium-low heat or in the oven at 300° until dry.
Desserts can leave lots of residue; a good scrub with a stiff-bristle brush and a little soap may be necessary. Just be sure to dry the pan thoroughly.