Cast iron seasoning—a protective layer of baked-on oil known as polymerization—is durable but can be damaged by a few common culprits. The most frequent causes of damage include thermal shock (cracking/warping), excessive high heat, harsh scouring, and simmering highly acidic foods for too long.
Why is my cast iron seasoning flaking or peeling? You've stripped away some seasoning, likely from cooking acidic foods (tomatoes, vinegar, citrus) for too long, or from aggressive scrubbing.
If the pan looks dry and/or gets small rusty spots, just touch up the seasoning. Think of cast iron like your skin. If it's dry, you moisturize. Make it part of your cleaning routine after using the pan.
Step 1: Strip Old Seasoning
Yes, you can use soap on cast iron. Modern dish soaps are safe for cast iron and won't damage seasoning. The old "no soap" rule comes from when soaps contained lye, which stripped seasoning. Today's soaps are gentle degreasers that help remove sticky residue without harming your pan.
Detergents aren't made with lye, so can't be soap. Either way you still shouldn't use soap with cast iron, but can use detergents, though there is no reason to do so. You can easily clean well maintained cast iron without it.
Everyone acts like soap will ruin cast iron… it won't. Modern dish soap isn't the harsh lye-based stuff that used to strip seasoning. A quick wash with mild soap, hot water, and a soft scrub just removes food and grease, not your seasoning.
If it's solid and intact, you can absolutelyrestore skillet surfaces, even if they look terrible.
Seasoning your cast iron creates a natural, non-stick surface through a process called polymerization, which bakes oil directly into the metal. To reseason your pan, scrub it thoroughly with soap and water, apply a very thin layer of high-smoke-point oil (like canola oil or Crisco), and bake it upside down at 450∘F to 500∘F for one hour.
If you're just swiping a layer of oil onto the surface of your skillet, you're not seasoning your cast iron correctly. Seasoning involves a chemical reaction made possible through heat.
Cast iron is built to last a lifetime, so it's only natural for the seasoning on your cookware to change over time. The more you cook, the stronger that seasoning gets. After cooking something acidic or dealing with a stuck-on mess, you might notice the seasoning looks a little dull, and that's okay.
4 Foods You Should Avoid Cooking In A Cast-Iron Skillet
The more you use a rusted pan, the more iron you'll consume in your food. It's best to avoid cooking with a rusty cast iron pan. If it's reached the point of corrosion or deep rust, throw it away rather than risk your and your family's health.
A well-seasoned cast iron skillet can help you achieve flavorful dishes, but if the skillet reaches extremely high temperatures — generally around 800 degrees Fahrenheit — all of that seasoning can burn off. This is the most common damage cast iron pans sustain.
5 Cast Iron Cleaning Mistakes Almost Everyone Makes—and How to Fix Them
Put the oiled pan in a preheated 450°F (230°C) oven, and leave it there for 30 minutes. It may get a little smoky, so keep your kitchen well ventilated. It's during this time that the oil will polymerize and form the first of several hard, plastic-like coatings you'll be laying down.
To restore a cast iron skillet, scrub away all rust and old flaky seasoning using steel wool or coarse salt. Wash with hot, soapy water, dry completely, and rub a very thin layer of high-smoke-point oil (like canola or avocado oil) over the entire pan. Bake upside down at 450°F to 500°F for one hour.
You're going to have to give your skillet at least six coats of oil and baking to create a hardwearing non stick base. Basically, new cast iron needs some intense TLC for the first year or so of it's life.
Yes, you can use steel wool on cast iron, but its usage depends entirely on what you are trying to accomplish.
To fix flaking cast iron, scrub away loose flakes with coarse salt or steel wool, wash the pan, and dry it completely. Apply a microscopic layer of high-smoke-point oil (e.g., grapeseed or canola) and bake it upside down in the oven for one hour.
Yes, vinegar can strip the seasoning from cast iron, but it is primarily designed to dissolve rust. Because vinegar is acidic, prolonged exposure will degrade and eat through the non-stick coating, potentially damaging the bare metal underneath.
A cast iron skillet is ruined primarily by rust from soaking or improper drying, warping from extreme thermal shock (like cold water on a hot pan), or cracking if dropped. While most seasoning issues are reversible, letting rust cause deep pitting, or fracturing the iron, destroys the cookware permanently.