Culinary Arts

How to Clean a Cast Iron Skillet

Written by MasterClass

Mar 7, 2019 • 5 min read

Every pan has its own quirks, but cast iron in particular has a reputation among home cooks for being high-maintenance. Don’t let that scare you off—a cast iron skillet can last a lifetime (or longer!) and is easy to maintain if you remember a few simple cleaning tips. If you ever mess it up, don’t worry: The great thing about cast iron is that it’s easy to restore.

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What Is a Cast Iron Skillet?

Cast-iron skillets are made of iron alloyed with a small amount of carbon to harden the material. Dense and a relatively poor conductor, cast iron can hold a lot of heat for a long amount of time, making it ideal for superhot applications, such as searing a steak. Since cast-iron pans are oven-safe, you can also use them to roast vegetables, or bake skillet cornbread.

What Does it Mean to Season Cast Iron?

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. Season your new cast iron at least once, prior to first use; continue seasoning as frequently or infrequently as you’d like. Every time you use your cast-iron pan, the cooking oil helps build up the protective, nonstick layer, getting more and more slick over time. Unlike Teflon, a chemical coating that flakes off over time, cast iron remains in tact, which is why cast-iron pans can become beloved heirlooms. Many new cast-iron pans are advertised as “pre-seasoned,” but even a pre-seasoned pan can benefit from additional seasoning at home.

How to Season a Cast Iron Pan

  • Stovetop: Heat skillet on the stovetop over medium-high heat and rub with a vegetable oil–soaked paper towel or rag. (You can use tongs to hold the towel.) Allow skillet to dry out on the stovetop. Repeat this process until skillet looks glossy, smooth, and dark, and is not sticky or patchy, about 3 rounds. Let cool and rub with a final light coat of oil and store in a dry place.
  • Oven: Heat oven to 500°F. Rub a light coat of vegetable oil all over your cast iron skillet with paper towels or rags, wiping away any excess oil. Place skillet upside down on the oven rack (to prevent pooling) and bake for one hour. The oil coating should be light enough that the skillet does not drip oil, but you can place a baking sheet on the rack below to catch any drips. Let cool and rub with a second light coat of oil and store in a dry place.

Should You Clean Cast Iron?

Although cast iron is very durable, it will rust when exposed to water or air, making the seasoning step crucial. Soaking with soap, over-scrubbing, or cooking highly acidic foods in cast iron can strip the seasoning. Clean your cast iron each use, wiping away leftover food morsels and reapplying the oil layer. If you maintain your pan’s seasoning through proper cleaning, it won’t rust and will have a natural nonstick finish slippery enough to fry an egg on.

What Materials Do You Need to Clean Cast Iron?

Oil: Any type of cooking fat can help build up a cast-iron skillet’s seasoning, but vegetable oils with a high percentage of polyunsaturated fatty acids will polymerize more readily, building the best seasoning (olive oil, butter, and coconut oil have relatively low proportions of polyunsaturated fatty acids). Some good options include:

  • Safflower oil (75% polyunsaturated fatty acids)
  • Grapeseed oil (68%)
  • Flaxseed oil (68%)
  • Corn oil (59%)
  • Sunflower seed oil (59%)
  • Soybean oil (58%)

Towels. Clean paper towels or rags.

A brush. Scrub brush with stiff non-metal bristles (such as nylon or tampico) or non-abrasive scrub pad or sponge.

How to Properly Clean a Cast Iron Pan

  1. Clean your cast iron skillet while it’s still warm. Wipe out any food with paper towels, a rag, or sponge and gently scrub any stuck-on bits with a brush or coarse salt. Rinse the skillet with hot water.
  2. Thoroughly dry with a rag or paper towels, or place the skillet on the stovetop over medium-low heat until dry, about 3-5 minutes. When the skillet is completely dry, apply a light coat of vegetable oil to the surface of the pan using a rag or paper towels. Rub the oil into the surface of the skillet until no oil residue remains. Store your cast iron skillet in a dry place.

8 Ways to Care for a Cast Iron Pan

  • Clean your cast iron-skillet immediately after use. Cleaning while it’s still warm will make it easier to remove stuck-on food.
  • Do not soak the pan. Prolonged exposure to water will increase the likelihood of rust.
  • Skimp on the soap. You don’t need to use soap to clean a cast iron skillet, but a small amount of mild soap should not damage the seasoning.
  • Only use steel wool or metal scouring pads if you’re planning to re-season the pan. If your pan becomes rusted, remove the rust by scrubbing with steel wool. Rinse, dry, and re-season.
  • Use coarse kosher salt as a gentle abrasive scrub to remove stuck-on food. Just apply a small amount of salt to the pan, rub with a damp sponge, and rinse.
  • Thoroughly dry your cast iron pan after cleaning. Use either a dry cloth or paper towels or briefly heat on the stovetop over low heat, to prevent rust. It’s normal to see a dark residue on your cleaning cloth from the seasoning interacting with cooked food. This should disappear after a few rounds of rubbing with a clean, oiled towel, but isn’t harmful regardless.
  • Do not put your cast iron pan in the dishwasher. The moisture and detergent could damage the seasoning.
  • Consider the ingredients. While you can technically cook anything in a cast iron pan, it’s not the best vehicle for scrambled eggs; acidic dishes that contain a lot of tomato sauce, wine, or vinegar; or delicate fish filets.

What’s the Difference Between Cast Iron and Carbon Steel?

Carbon steel, like cast iron, is made up primarily of iron. Carbon steel contains slightly less carbon than cast iron and is less brittle, which means it can be formed into thinner pans. Like cast iron, carbon steel has great heat retention, which is why it’s popular in restaurant kitchens. Carbon steel is also prone to rusting and must be properly seasoned. Use the same methods for protecting and cleaning carbon steel as you would cast iron.