How To Spot A Bad Cast Iron Pan: A Guide To Avoiding Common Pitfalls

Cast iron pans are resilient and difficult to ruin. However, there are some common issues that can occur with cast iron pans, such as:

- Discolouration: When using a new cast iron skillet, the cooking surface may become patchy or uneven in colour. This is normal for a new cast iron skillet, especially those of higher quality with a smooth surface.

- Flaky seasoning: This can be caused by too many thick layers of seasoning or by seasoning with certain types of oil, like flaxseed. It can also be caused by cooking the wrong types of food, like an acidic sauce or a salty broth.

- Oil residue: This can occur when you use too much oil when seasoning, or if some oil hasn't fully polymerised and turned into seasoning yet.

- Rust: Caused by moisture, even something as simple as not drying your pan thoroughly can result in rust.

- Scratches: Seasoning can get scratched if you cut something directly in your cast iron skillet or use a metal utensil at the wrong angle.

If you encounter any of these issues, don't worry – cast iron pans are tough and most problems can be fixed with a bit of elbow grease and patience.

Discolouration

Most discolouration is completely normal in cast iron pans, especially those that have been used for years. However, since it can be difficult to differentiate between discolouration and rust, it is important to inspect your pan closely. Rust can be hazardous to your health if consumed, as it can lead to tetanus if it has been exposed to the bacteria Clostridium tetani. Therefore, if you notice any red or orange hues on your pan, it is best to discard it.

If your pan has discoloured due to exposure to sunlight or heat, this is usually not a cause for concern. The discolouration may add character to your cookware and will not affect its performance. However, if the discolouration is accompanied by a strange, rough texture, this could be a sign of corrosion and rust, which are dangerous to your health and should be avoided.

To prevent discolouration and rust, always dry your cast iron pan thoroughly after washing and rub it with a light layer of cooking oil. Store your pan in a dry, moisture-free environment to avoid exposure to humidity, which can cause rust.

Rust

Identifying Rust:

Removing Rust:

The process of removing rust will depend on the extent of the problem. For minor surface rust, a scouring pad or kitchen towel can be used to rub kosher salt or a mild abrasive sponge into the rusty areas. For more serious cases, a vinegar soak is recommended. This involves submerging the entire pan, including the handle, in a mixture of equal parts water and distilled white vinegar. The pan should be removed from the solution once the rust easily flakes away, which can take up to eight hours. It is important to frequently check on the pan during the vinegar soak, as prolonged exposure can damage the original cast surface of the pan.

After removing the rust, the pan should be washed with mild dish soap and warm water, and any remaining rust can be cleaned with a mildly abrasive sponge. The pan should then be dried thoroughly with a kitchen or paper towel, and placed on the stovetop over low heat to ensure complete dryness.

Preventing Future Rust:

To prevent future rust, it is crucial to properly season the pan. This involves coating the pan with a thin layer of cooking oil and heating it in the oven at a high temperature (around 450-500°F). This process creates a protective layer of fat molecules that not only makes the pan non-stick but also protects it from rust.

In addition to proper seasoning, cast iron pans should always be dried thoroughly before storage and kept in a low-humidity environment. Stacking multiple pans together is not recommended, but if necessary, each pan should be lined with paper or a kitchen towel to absorb any moisture.

Scratches

Light scratches on the seasoning are nothing to worry about. In fact, some people believe that they can aid in seasoning over time. You can fill in scratches by cooking with a metal spatula that has a straight, rather than rounded, edge. This will help to keep the surface smooth. Cooking bacon is also a good way to fill in scratches.

To prevent scratches, it's important to follow the correct cleaning procedures. Avoid using steel wool, scouring pads, or detergent scrubs, as these can damage the seasoning. Instead, use a gentle detergent scrub, such as Bon Ami or Bar Keepers Friend, to clean off any stuck-on food or rust. You can also try scrubbing the pan with kosher salt, then wiping it out with a cloth, adding vegetable oil, and heating over medium-low heat for 5 minutes. Remove the pan from the heat, add more kosher salt, and scrub with a thick cushion of paper towels held with tongs. The warm oil will loosen any remaining food, and the salt will provide an abrading effect without damaging the pan's seasoning.

If you do accidentally scratch the cast iron, it's not the end of the world. Cast iron is nearly indestructible, and the marks just add to the unique patina that every pan develops. However, if you want to get rid of the scratches, you can try sanding them out or stripping and re-seasoning the pan.

Stripped seasoning

If your cast iron pan looks like it has stripped seasoning, don't panic! Cast iron is extremely resilient and difficult to ruin. Even if you strip away most of the seasoning, you can still rebuild it.

How to Identify Stripped Seasoning

Cast iron pans develop many thin, interlocking layers of seasoning on their surface over time. Each time you cook in your skillet, it will gain and lose seasoning in different spots, which can cause some discoloration. If you see some raised, splotchy residue on your skillet, which often looks like a spiderweb or spotted pattern, this is most likely some oil residue.

How to Fix Stripped Seasoning

First, gently wash your pan to remove any loose seasoning or residue. Then, follow these oven seasoning instructions two to three times:

• Scrub skillet with hot soapy water and a scouring pad or steel wool to remove all rust and former seasoning.
• Dry thoroughly by placing it in a 200°F oven for 5-10 minutes.
• Spread a thin layer of extra virgin coconut oil or flaxseed oil on all sides of the skillet (including the handle and bottom side of the pan).
• Wipe off all excess oil with a paper towel.
• Put the pan upside down on a rack in a 375°F oven.
• Bake for 30 minutes. After 30 minutes, turn off the oven and let cool for 10-15 minutes (or until safe to handle).

Repeat the above steps several times (or as necessary) until you’ve built up multiple layers of seasoning and the coating is sufficiently nonstick (you should be able to fry an egg in butter or oil without it sticking).

Tips for Seasoning a Cast Iron Pan

• Strip your cast iron outside in a fire pit to avoid stinking up your house.
• Protect your counter with a sacrificial towel, as the seasoning process can be messy.
• Use a roll of paper towels to avoid ruining your towels.
• When adding oil to your pan, don't use too much. It's better to use multiple thin layers than one thick layer, which will result in a thick, sticky coating that won't be smooth or non-stick.
• Season your cast iron pans on a day you can open the windows, as the process can be smelly.
• Continue the seasoning process until you can run a paper towel over the surface of the pan without getting any residue.
• Seasoning cast iron works best if you can season your pan up to four times.
• New pans may only require one additional coat of seasoning.
• Older pans may require more than four applications. Let the residue on the paper towel be your guide.

Food sticking to the pan

Temperature Control:

The temperature of the pan plays a crucial role in preventing food from sticking. Firstly, ensure that you preheat your cast iron skillet for about 4 to 5 minutes to establish an even heat distribution. Cast iron retains heat very well, so you might not need the same high heat settings you would use with other materials. After preheating, you may even need to reduce the temperature slightly as cast iron continues to absorb heat. For foods like bacon, medium heat is recommended, while for eggs, potatoes, or vegetables, low to medium-low heat is ideal.

Oil Usage:

Using the right amount and type of oil is essential. Before adding your food, make sure there's enough oil to coat the bottom of the pan. For foods prone to sticking, like eggs, you may need a bit more oil. On the other hand, fatty foods like chicken thighs don't require as much. It's also important to ensure that the oil is hot before adding your ingredients. A shimmering appearance is a good indication that the oil is ready. If the oil starts to smoke, it's too hot, so remove it from the heat for a couple of minutes to cool it down.

When cooking at high temperatures, opt for neutral oils with high smoke points, such as canola oil or grapeseed oil. These oils have little to no flavor, making them ideal for stir-fries and frying. For low-temperature cooking, olive oil is a great option. Additionally, if you're using butter, it's helpful to start with a thin layer of oil underneath to prevent sticking or burning.

Ingredient Temperature:

Using room-temperature ingredients can also help prevent sticking. Adding cold ingredients to a hot pan can cause a drop in temperature, making the surface more prone to sticking. So, when possible, remove your ingredients from the fridge a few minutes before cooking and let them come up to room temperature.

Pan Maintenance:

Properly maintaining your cast iron cookware is crucial. Regularly clean and season your pan to create a non-stick surface. If food does stick, you can try simmering a little water in the pan for a few minutes and then using a pan scraper or metal spatula to remove the residue. If that doesn't work, follow the re-seasoning instructions provided by the manufacturer.

Cooking Technique:

Finally, be patient when cooking. Don't move or flip your food too quickly. Allow it to develop a surface before attempting to turn it. This initial searing will help prevent sticking and give your food a nice caramelized crust.

By following these instructions, you should be able to significantly reduce the amount of food sticking to your cast iron pan, resulting in better dishes and a more enjoyable cooking experience.

Frequently asked questions