Restoring Cast-Iron: How to Remove Rust From Cast-Iron Pans

Cast-iron is an iron-carbon alloy that is closely related to steel. It contains slightly more carbon than the stainless steel found in many devices, and it has a lower melting point than steel. Cast-iron has long found favor as a cooking surface because it naturally holds heat for long periods of time.

Cast-iron corrodes easily, so it’s necessary to protect its surface by “seasoning,” or creating a barrier in which the fatty acid chains of the seasoning oil polymerize, or bond together, in the presence of heat and air, forming a glossy sheen. A properly seasoned pan functions as a nonstick cooking surface without the use of a Teflon coating.

The next time you find yourself staring down a rusty cast-iron skillet, Dutch oven, or even stovetop, try these simple steps to remove the rust. Prepare to exert a good deal of elbow grease.

1. 1. Use an abrasive scrub pad. Abrasive scouring pads will remove the surface of a seasoned pan, but when cast-iron rust is allowed to build up, it takes a rough scrubber to remove it. Try using a wire brush or a steel wool pad. Add a little hot water to help the process along.
2. 2. Add baking soda and vinegar. If simple scrubbing doesn't do much to remove rust from your pan, coat the entire skillet in a thin layer of baking soda. Add a few drops of warm water, which will help it cake on the surface of the pan. Then pour white vinegar onto the baking soda. It will begin bubbling and the liquid will turn cold. Let this mixture sit for upwards of a half hour and then resume scrubbing.
3. 3. Try scrubbing with salt. Some chefs find luck using kosher salt or sea salt to help them scour a pan. Place a liberal amount of coarse salt in the pan, add a bit of warm water to make a paste, and then rub it around using a scrubber.
4. 4. If the rust is stubborn, try dish soap. Soap can eat away at the oily seasoning built up in the pan if exposed for long enough. However, soap may be necessary to rescue your cast-iron pan from rust. Once you've put soapy water in the pan, use steel wool to scrub it down. In most cases, this will remove the rust lining your pan.
5. 5. Quickly dry the pan. Once your scrubbing is done, you'll need to dry your cast-iron skillet quickly since standing water is the culprit behind rust. Use paper towels or clean dish towels that you don't care much about because cast-iron can stain fabric. Once the pan is dry, you can move on to reseasoning it.

Once your cast-iron cookware is rust-free, it's time to reseason it. Consider this simple method for doing so.

1. 1. Preheat your oven. You'll be placing your cast-iron cookware in an oven, so preheat it to 350 degrees Fahrenheit. Place a baking sheet lined with aluminum foil inside the oven to catch oil drippings.
2. 2. Oil up the pan. Coat the entire pan—particularly the cooking surface—with a thin layer of oil. Most types of vegetable oil will do, but canola oil and corn oil are good choices for the seasoning process because they have high smoke points. Grapeseed oil is favored by some chefs, but take note that its smoke point is 390 degrees Fahrenheit. Avoid using low smoke point oils like flaxseed oil or extra virgin olive oil. In some cases, chefs make a layer of seasoning out of lard, but this will make the pan unsuitable for vegetarian cooking. Lard also has a relatively low smoke point.
3. 3. Place the pan upside down on the foil-lined baking sheet. The next step as you re-season cast-iron is to let it reach a high heat. Open the oven and set your pan upside down on the baking sheet you preheated in step one. The pan and foil-lined sheet should sit on the bottom rack of your oven.
4. 4. Let the cookware bake for one hour. One hour at 350 degrees should burn off all excess cooking oil while letting your pan retain its signature seasoning.
5. 5. Let your pan cool. The final step in re-seasoning is to let the pan cool off in the oven. Once your pan has cooled off, it is ready to use again. You can use this seasoning method on brand new pans—including pre-seasoned ones—to improve the quality of your cookware.

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