Cast iron is one of the most durable materials out there, and can be the perfect instrument for heating, searing and serving some incredible meals. But it also requires different care than the other pots and pans in your kitchen. Thankfully, a few simple cleaning and care steps will remove rust, prevent any future damage and ensure your skillet can cook delicious meals for generations to come.
It's important to remember that while cast iron is tough, it must be cleaned gently. That's because the most important part of a cast iron skillet is its seasoning, the layer of animal fat or vegetable oil that coats the pan. The seasoning protects the bare cast iron and also creates a non-stick surface. Too much scrubbing or harsh soap can wear away at that seasoning, leaving you with a pan that rusts and sticks to foods.
Don't Let It Linger
Clean your cast iron skillet as soon as possible after using it. Use warm water and a soft sponge to gently wipe off any residue. Stay away from harsh scrubbing tools like steel wool; that can tear right through your skillet's seasoning. If you want something with a little more power, pour half a cup of coarse salt into the pan and scour it with a kitchen towel. The salt should act as an exfoliant and loosen any stuck-on food. Rinse well with warm water afterwards.
Attacking the Gunk
There are cast iron purists who won't let any soap near their skillet. That's okay, since coarse salt, gentle scrubbing and warm water usually do the trick. But more chefs are realizing that it's usually okay to attack stubborn grime with a little soap. If you're having a tough time with some caked-on gunk, put two or three small drops of a mild dish soap on a soft sponge. Scrub gently, and rinse well with warm water as soon as you're done. The soap should not leave behind any oils that will eat away at the polymerized oil of the pan's seasoning.
You don't have to ditch a skillet just because of a little rust. Small bits of rust should come off with coarse salt and mild soap. But if your pan is coated in rust, you may have to take more drastic measures and resort to removing the rust and seasoning with steel wool. If that's the case, scour the skillet with a soapy steel wool sponge until your skillet is bare cast iron. Then, wash and dry the skillet once more as if it still had its seasoning. Lastly, you'll have to re-season the pan. Coat the entire pan (handle and bottom included) in a heat-friendly, unsaturated oil such as vegetable, corn, canola or flaxseed. Then, place the pan upside down in your oven at 350 degrees for one hour. This method helps the oil stick, or polymerize, to the pan.
Dry, Dry, Dry!
If you've just taken your skillet out of the oven after removing rust and re-seasoning it, it will be good to go for next time. But if you've simply cleaned it after use, make sure that it is completely dry after cleaning. This is the biggest mistake that people make when caring for their skillet. The smallest bit of water left behind can lead to rust. Use a completely dry towel to pat down your entire skillet.
Prime and Store
A light priming will add to your skillet's seasoning and guarantee that your pan will be ready to use next time you're hungry. Spread a very thin layer of a heat-friendly, unsaturated oil such as vegetable, canola, corn or flaxseed around the entire skillet. You might have to buff it a little with a paper towel. The pan shouldn't look or feel greasy. Last, heat the pan up one more time until it starts to smoke a little. This will help that thin layer of oil bond to the pan, making sure that the skillet isn't too sticky the next time you use it. Store your skillet in a room temperature area and make sure it is not exposed to humidity.