Cooks for generations didn't use soap on cast iron pans because the soaps were made with lye and vinegar, two ingredients that will absolutely strip the seasoning and can even damage the pan's iron.
Today's aerosol oven cleaners are often made with lye or sodium hydroxide. While these cleaners are great for cleaning messy ovens and even getting burnt-on gunk off Pyrex, they can rapidly destroy seasoning on cast iron pans.
But today's dish soaps just don't have that kind of power. These milder soaps will rinse away surface oil and food debris, but they aren't strong enough to touch the nonstick seasoning. So you can safely use your favorite dish soap to clean up after making Potato-Bacon Hash or Skillet Caramel Apple Pie.
If you don't quite trust us, trust the fine folks at Lodge Cast Iron in South Pittsburg, Tennessee. They endorse the soap method, too, and they have over 120 years of experience making cast iron.
How to Remove Rust from a Cast-Iron Skillet
You'll need:
- Steel wool
- Sponge (with a scrubber side)
- Mild dish soap
- Vegetable oil
Step 1: Scour
Ignore all those times you've been told to be gentle with your cast-iron skillet. The reason to be gentle while cleaning is to preserve the seasoning. The iron itself is virtually indestructible. Here, you're going to strip away all the rust (and the seasoning). Don't worry-we'll add more seasoning later.
It's going to take a little bit of elbow grease and a hard abrasive tool to remove the rust. Get the pan wet, add a little soap, and then go to town with your scrubber (depending on the level of rust, a tough sponge will do). Scrub in small circles, focusing on the rustiest parts first. Continue scrubbing until you see the original black iron emerge.
Test Kitchen tip: Have a newer pan that's developing small amounts of rust? There's an easier way to restore it to new. Simply dampen a paper towel with oil and use it to wipe away the rust. Continue wiping the entire skillet, then skip to step 3.
Step 2: Rinse
At this point you've likely worked up a copper-brown mush. Rinse that gunk off in the sink. Make sure your skillet is clean by doing another scrub this time with a soft soapy sponge. Buff off any residue or rusty bits that remain.
Step 3: Dry
With the rust completely removed, your cast-iron skillet should be looking almost back to normal. But without any seasoning, it'll have a dark gray, matte finish. Dry it off with a clean dish rag. (Psst. Don't use a rag you're fond of. The skillet can leave dark stains!) To dry it completely, place the skillet on the stove and turn on the heat for a few minutes. Any lingering moisture will evaporate right off.
Step 4: Re-season
Now that you've returned your skillet to its base layer, you'll need to season it for use. Drop a tablespoon of vegetable oil on the pan and spread it around with your fingers or a paper towel. (Take care not to burn yourself on a warm skillet!). Oil the outside and the handle, too. Next, take a folded napkin and wipe off the excess oil. You'll want the skillet to be lightly greased. Set your oven to 350 degrees and put some aluminum foil on the bottom rack. Then pop the skillet in, upside down, on the upper rack for about 1 hour. Turn the oven off and leave the pan inside until it's cool. The oil will bake into the pores of the pan, providing a non-stick finish.
Repeat this step a second time and you'll have an almost glassy surface of seasoning.
