Simply Put, Rusty Cast Iron is No Big Deal. Learn Why

Is it Preventable?

Absolutely! Contrary to popular belief, washing cast iron in soapy water is fine! The problem is if your cast iron pan is not properly dried afterward. Not just the cooking surface, but the entire thing. 

Regularly maintain it with a layer of seasoning oil, especially after using it to cook acidic foods like tomatoes. Avoid minor pitting to the smooth surface caused by overenthusiastic scraping with metal utensils or abrasive sponges, better to use coarse salt as a gentle scrub to remove food residue. Always dry the entire surface after use and store it in a low-humidity spot.

Will it need to be reseasoned?

Yes. Once you clean off the rust spots, the protective seasoning needs to be restored. This process involves coating the pan in a very thin layer of oil and bake it at 400°F for one hour to create a non-stick, rust-resistant surface. This only needs to be done periodically, because the coat of oil your pan receives as you cook with it is contributing to its protective layer, too.

How to Clean Rusty Cast Iron

You'll Need

• Steel wool or a scouring pad
• Dish soap (optional, for heavy rust)
• Warm water
• Paper towels or a lint-free cloth
• High-smoke-point neutral cooking oil (like canola oil, grapeseed oil, or flax seed oil)
• Oven

1. Remove the Rust

• The only time to use harsh abrasives on your cast iron is to remove the spots of rust that developed. Scrub the rusted areas using steel wool or a scouring pad.
• Use firm pressure and work in circular motions to lift the rust.
• Rinse the pan under warm water periodically to check your progress.

2. Wash and Dry Thoroughly

• Wash the pan with warm water to remove any remaining debris.
• If using soap, rinse it off completely.
• Dry the pan immediately with paper towels or a dry cloth. A very thorough drying process would be to place it in a hot oven or on a stove over medium-low heat before tackling the cast iron finish.

3. Reapply the Seasoning

• Preheat your oven to 450°F (232°C).
• Repair the nonstick layer by applying a very thin, even layer of oil to the entire pan, including the handle and bottom.
• Use a paper towel to wipe off excess oil—too much can lead to a sticky residue.

4. Bake the Pan

• Place the pan upside down on the oven rack to prevent pooling.
• Bake for 1 hour, then turn off the oven and let the pan cool completely inside.
• Repeat the oiling and baking process 2–3 times for best results.

FAQ

Can I use vinegar to clean rust off cast iron?

Yes, from time to time you can spot treat by dabbing vinegar onto minor surface rust. If you've picked up a flea market cast iron skillet with severe rust, you can soak the pan in a 1:1 solution of white vinegar and water for up to an hour to dissolve the iron oxide. However, this vinegar solution should really only be used in extreme cases as an extended period in vinegar candamage the metal. You will likely need to oil and bake it several times afterwards to build up the layers of seasoning again.

What if my pan has stubborn, deep rust?

If scrubbing and vinegar don’t work, consider using a rust eraser or electrolysis cleaning (a DIY method using a battery charger). However, these methods should only be used as a last resort. Even a high-quality, durable vintage cookware has a point of no return.

Is it safe to cook with cast iron after removing rust?

Yes! Once the rust is removed and the pan is properly reseasoned, it’s perfectly safe to use. Cast iron pans are an incredibly resilient piece of cookware and can last for generations with proper care.