Cooking acidic foods or following improper cleaning procedures can damage the seasoning on your pan, creating spots of dull, patchy, dry-looking metal on the inside of the pan instead of the smooth, rich black of well-seasoned cast iron.
The dullness comes when the oil on the pan burns off before cooking. To fix this, just re-season the pan. If your cast iron still looks dull after re-seasoning it, repeat the process until it achieves a slight sheen.
So, why does cast iron look splotchy after seasoning it? Splotchy, patchy, or uneven cast iron is caused by using too much oil during the seasoning process. To fix it, scour the pan with steel wool to remove old seasoning. Wash and dry the pan.
The skillet turning grey basically means you burned off the seasoning. The natural color of cast iron before it is oxidized and with no coating is grey, metallic, and shiny. To bring it back to black, over time as the seasoning turns to polymers, it will darken.
Although it seems odd, it is technically possible to over-season a skillet. Too much oil baked into the cast iron will cause it to polymerize unevenly and eventually will cause the surface of the skillet to flake. Adding too much oil when seasoning will also cause your pan to become sticky, notes Lodge.
A well-seasoned cast iron pan should be dark black, shiny, and smooth to the touch. Unseasoned cast iron has a rough look and feel until it is properly seasoned.
Using too much oil, anything more than about the size of a quarter will just build up and cause an oil slick on your pan. When it's time to season your cast iron skillet, you simply can't do this with a cold skillet. This will cause build up of that oil residue, and cause stickiness.
Newly seasoned cast iron may have a brownish tint to it. It's not rust, it's just the initial patina baking in. It can take a few coats of seasoning and some use to get a black finish. Don't worry about the brownish colour - go right ahead and use the pan.
A well-seasoned skillet will have a dark, semiglossy finish and won't be sticky or greasy to the touch. It won't have any rust or any dull or dry patches. An easy way to test a skillet's seasoning is to fry an egg (heat 1 tablespoon vegetable oil in skillet over medium heat for 3 minutes, then add egg).
If the seasoning in your pan is sticky, this is a sign of excess oil built up on the cookware. The Fix: To remedy stickiness, place the cookware upside down on the top rack of the oven and bake at 450-500 degrees F for one hour. Allow to cool and repeat if necessary.
After the first hour is up, let the pan cool naturally in the oven for 1 hour, then repeat the process a total of 6 times – yes, 6 TIMES ! This is the most ideal way to insure your pan will have the darkest, most even & hardest seasoning you've ever seen in an iron skillet!
What should a cast iron skillet look like after seasoning? If you know how to clean a sticky cast iron skillet and get it well-seasoned, it will shine. It'll also be dark black in color, and smooth when touched. If cast iron is unseasoned, it will have a rough look and feel to it.
Place the cookware in the oven upside down. Place a large baking sheet or aluminum foil on the bottom rack. Bake at 450-500 degrees F for one hour. Allow to cool.
Rub a thin layer of vegetable oil on the pan, including the handle. Place the pan in an unheated oven with a layer of tin foil on the rack below to catch any drips from the oil. Turn the oven on to 350° and bake your pan for an hour. Allow the pan to cool and repeat 2 more times.
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.
Whereas unseasoned cast iron is silver-gray, a seasoned pan will generally be black or brown all over. You'll know a pan is well-seasoned if it's an even color all over, without darker specks or blotches.
Warm Up the Cast Iron-
Set your clean and dry skillet in a 200° F oven for 15 minutes. Heat opens the pores of cast iron, so that it will easily accept the seasoning.
You should only need to fully re-season your cast-iron cookware one to two times a year, but you may also want to give it some extra seasoning love anytime you cook something that requires a heavy-duty cleaning.
Can I use steel wool or a metal scrubber to clean my cast iron pan? No! We recommend using a pan scraper or the Lodge Chainmail Scrubber to remove any stuck-on residue.
A well-seasoned cast iron pan should have a smooth, non-stick surface that allows food to slide off easily. If the surface is sticky, food can stick to the pan, making it difficult to cook and clean. If the pan does become sticky, it may need to be stripped and re-seasoned to restore its non-stick properties.
All cooking oils and fats can be used for seasoning cast iron, but based on availability, affordability, effectiveness, and having a high smoke point, Lodge recommends vegetable oil, melted shortening, or canola oil, like our Seasoning Spray.