The Peeling Pan Mystery: Why Cast Iron Needs Care

It's not unusual to see flakes of seasoning peeling off your cast iron pan. This is often due to the thin, factory pre-seasoning layer coming off during initial cooking or cleaning, or because additional seasoning layers have not properly bonded with the iron. The solution is to scrub off the loose bits and re-season the pan.

Factory pre-seasoning layer peeling off

It is not unusual for the factory pre-seasoning layer to peel off cast iron pans during initial cooking or cleaning. This is because the polymerization process that creates the seasoning layer on the pan requires the oil to be in contact with both iron and oxygen. If too much oil is used, the chemical reaction cannot occur properly, and you are left with a sticky mess that will cause flaking.

To fix this, you should first lightly scour the surface of the pan to remove the flaky seasoning layer. Normally, you would not want to scour the surface of cast iron as it can damage the seasoning, but in this case, you are aiming to remove the flaky layer. You can use steel wool, a Brillo pad, a rough-textured sponge, or a handful of coarse salt and a rag. You probably won't be able to remove all of the seasoning, but that is okay. The goal is to remove as much of the flaky, peeling portion as possible.

Next, wash and dry the pan thoroughly. Use dish soap and water to wash the pan, removing any residual flaky residue. Rinse the pan in cold water to help prevent flash rust from forming on the bare metal. Dry the pan well with a towel.

Finally, re-season the pan. Pre-heat the oven to 450 degrees F. Use a lint-free cloth to rub cooking oil over all surfaces of the cast iron pan. Once the oil has been applied, take another clean, lint-free cloth and buff all surfaces of the pan to remove the excess oil. Place the pan upside down on the middle oven rack and heat for an hour. When the hour is up, turn off the oven but don't remove the pan. Crack the oven door open a few inches and let the pan cool off gradually until it is safe to handle. Repeat the oiling and heating process two to three more times to build up a strong seasoning layer that resists flaking and peeling.

A strong seasoning layer is your best defense against flaking or peeling cast iron cookware. Don't settle for the thin layer of pre-seasoning applied by the factory. Always season your pan an additional one or two times before cooking with it.

Oil not reaching the right temperature

Cast iron skillets are a great addition to your kitchenware, and they get better with age! However, they do require some extra care to ensure they remain in good condition. One of the most important things to do is to properly season your cast iron skillet, which involves baking oil onto the surface of the pan. This process, known as polymerization, creates a protective layer that prevents rust and makes the pan non-stick.

One common issue that can occur when seasoning a cast iron pan is not heating the oil to a high enough temperature. If the oil doesn't reach its smoke point, it won't completely bond with the cast iron. This will result in a brown, sticky layer that will eventually flake off. To avoid this, it's important to choose an oil with a high smoke point, such as avocado oil, grapeseed oil, or canola oil.

When seasoning your cast iron pan, it's crucial to heat the oil beyond its smoke point. This is the temperature at which the oil starts to smoke and break down. For most oils, this temperature falls between 400-500 degrees Fahrenheit. By heating the oil past this point, you ensure that it fully bonds with the cast iron, creating a strong, slick surface.

In addition to choosing the right oil, it's important to apply a thin, even layer to the pan. Using too much oil will result in a sticky mess that won't properly bond with the iron. It's also important to heat the pan for a sufficient amount of time, typically about an hour at a high temperature. This allows the polymerization process to occur, transforming the oil into a hard, black surface.

By following these steps and ensuring your oil reaches the right temperature, you can create a strong, durable seasoning on your cast iron skillet that will last for years to come.

Using metal utensils

While cast iron pans are very durable, the surface of the pan can be susceptible to scratches, gouges, and peeling from metal utensils. However, the seasoning in cast iron pans is actually remarkably resilient. It's not just stuck to the surface—it's chemically bonded to the metal. So, unless you're gouging out the surface of the metal, you should be able to continue cooking with no issues.

That said, it's important to note that cast iron skillets are not completely invulnerable to damage from metal utensils. The main concern is that metal tools can more easily chip off the protective seasoning that takes time and effort to build up. This is especially true for pans that are brand new, have only been seasoned once, or are older pans that have been re-seasoned after losing most of their coating. In these cases, it's recommended to opt for more gentle utensils, such as those made of wood or silicone, to allow the seasoning to settle in and toughen up.

For enamel-coated cast iron cookware, the advice is similar. While some sources say it's okay to use metal utensils as long as you avoid hitting or jabbing the pot firmly, others note that these pans are more liable to scratches and damage. So, while metal utensils can be used if you're extra gentle, it's probably better to stick to wood or silicone to keep your cookware in pristine condition.

In summary, while it's generally safe to use metal utensils with cast iron pans, it's important to be cautious during the initial seasoning stages and with older pans that have been re-seasoned. Opting for gentler utensils in these cases will help protect the seasoning and the pan itself.

Cooking acidic foods

To avoid these issues, it is recommended to use a well-seasoned pan when cooking acidic foods. You can build up the seasoning on your pan by regularly cooking foods like cornbread and sautéed vegetables. Additionally, try to keep the cooking time for acidic foods under 30 minutes. If you need to simmer acidic ingredients for a long time, it is better to use an enameled cast-iron pan or a stainless-steel pan.

When cooking acidic foods, be mindful of the type of ingredients you are using. Canned tomatoes have a pH of around 4, which is less acidic than wine (3 to 4), vinegar (2.5), and citrus juice (around 2). So, while it is safe to cook tomato- and wine-based sauces in cast iron, it is better to dilute vinegar or citrus juice with water or stock or use a different type of pan.

After cooking acidic foods, be sure to clean your cast-iron pan as soon as possible. This will help prevent any remaining acidic ingredients from breaking down the seasoning on your pan. Proper care and maintenance of your cast-iron pan will ensure that it remains in good condition and can handle cooking acidic foods without any issues.

Using too much oil

Cast iron pans can peel, and this is often due to the thin, factory pre-seasoning layer coming off during initial cooking or cleaning. However, another common cause of peeling is using too much oil when seasoning the pan.

Cast iron seasoning is created by applying multiple thin layers of oil baked onto the surface of the pan at a high temperature. This process, called polymerization, causes the liquid oil to bond with the iron on a molecular level and transform into a slick, hard surface.

When it comes to seasoning a cast iron pan, less is more. Using too much oil will result in a sticky, goopy mess that will peel off. The key is to apply multiple thin layers of seasoning. Each layer of oil should be buffed off with a cloth, removing as much oil as possible. There will still be enough oil in the tiny pores of the iron to produce a good seasoning layer without causing streaking, stickiness, and flaking.

To avoid using too much oil, it's recommended to use a lint-free cloth to apply the oil to the pan. After applying the oil, use another clean cloth to buff all surfaces of the pan and remove any excess. The pan should then be placed upside down in the oven and heated for about an hour at a temperature between 450 and 500 degrees Fahrenheit.

By following these steps and using the proper amount of oil, you can avoid the issue of peeling caused by excess oil and maintain a well-seasoned cast iron pan.

Frequently asked questions