Bare cast iron is highly susceptible to corrosion, so if you've stripped away any of the seasoning (the black protective layer of polymerized oil) in the process of cleaning or just normal use, you need to re-season your pan to prevent rust and restore its naturally nonstick cooking surface.
Yes! (Practically) Oil-free cooking is possible in cast-iron. I am personally not concerned about using very small amounts of oil in our cooking, but I know people who try to be as oil-free as can be.
You let your skillet soak.
Soaking your cast iron skillet in your sink is a recipe for rust, as is washing it in the dishwasher. Instead, clean it ASAP, even using simple soap and water if you must.
That's why our simple cleaning steps have you rub oil into your pan after each use to ensure the seasoning remains for quality cooking. You can also season your cast iron cookware in the oven. This method adds a more thorough layer of seasoning onto the entire pan, strengthening the bond to the iron.
A new uncoated or non-seasoned cast iron fry pan also must be cured or seasoned before you can use them―there's no way around that.
A lot more (if your skillet isn't properly seasoned)
Cooking on unseasoned cast iron can result in sticking, rusting, and a myriad of other issues (some of which are outlined above).
Dry it off: It is important to rinse and dry your cast iron skillet immediately after cleaning. We recommend using a lint-free towel. NEVER allow cast iron to air-dry as this can allow rust to build.
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.
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).
Cast iron pans can leach a sizeable amount of iron into your food, exceeding dietary intake in some cases. Acidic foods will contribute to much more leaching while an old, heavily-seasoned pan will leach much less iron than a newer one.
Several of our consulted chefs agreed that cast iron can leave an unpleasant flavor layer in tomato-based dishes. The "naked" cast-iron cooking surface of an unenameled skillet can cause "acidic foods to become discolored and acquire a metallic taste," says Weinstein.
First, it's important to always heat up the pan prior to adding any oil, butter, or fat. When cooking on cast iron, when it comes to fat, less is not always more. It's better to err on the side of too much fat, and then simply drain any excess after cooking.
The oily nature of cast iron not only helps keep it rust-free, but also adds natural nonstick qualities to the pan and enhances flavor over time. If you let cast iron sit too long without use, the oil that's soaked into the metal can get old and pick up an “off” smell.
These are all fats with high smoke points, which means they will bake on cleanly instead of turning sticky. Do not use olive oil or butter to season your cast-iron pan — they're great to cook with, just not for initial seasoning.
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.
Heat oven to 500 degrees. Using paper towels, rub 1 tablespoon (for 12-inch skillet) or 2 teaspoons (for 10-inch skillet) oil over surface. Using clean paper towels, thoroughly wipe out excess oil (surface should look dark and smooth). Place skillet in oven for 1 hour.
Generally, we recommend seasoning your cast iron about once per month, but after every time you use it works as well if you find that it could use some seasoning. What type of oil is best for seasoning a cast iron skillet? Canola, vegetable, or coconut oil are best.
Water boils at 212º and cast iron pans without an enamel coating can withstand up to 1500°F. So boiling a little water won't damage your pan. If you don't season your pan well, rust can form in no time, though. If you boil water for too long, you risk wearing down the layer of seasoning.
Unfortunately, as a result, soaking is a surefire way to end up with a rusty cast iron skillet. Similarly, you should always make sure your pan is completely dry before putting it away, as any residual water can also cause rust.
Your cast iron can withstand heat - a lot of heat. A cast-iron skillet can withstand heats of up to 1500°F, which is much hotter than your oven could ever be. The seasoning will only burn off at about 800°F, so don't worry that you will damage your pan by cooking with high heat.
Sticking your skillet into a roaring fire might seem like a good way to heat it up in a hurry, but overheating or uneven heating can cause your skillet to take on a permanent warp, or even crack. Same goes for pouring cold water into a red-hot pan.
When cooking on a rusted cast iron there's a chance that some of that material will end up in your food. However, the quantities are so small that they're almost negligible. Even though a rusted cast-iron pan doesn't necessarily present a health concern, it's still not recommended that you cook on it.