Rusty Cast Iron Pans: Safe To Use Or A Health Hazard?

Cast-iron pans are a popular choice for home cooks due to their high quality, affordability, and excellent heat distribution and retention. However, one common issue that plagues even the most experienced cooks is the formation of rust. This occurs when cast iron, a naturally porous material, is exposed to water and oxygen for extended periods, resulting in an unsightly orange layer on the pan's surface. While a rusty cast-iron pan may not be aesthetically pleasing, is it safe to use?

How to remove rust from cast iron

Cast iron is a naturally porous material that develops rust when it interacts with water and oxygen. This means that exposing your pan to water for a long time can quickly create an orange, rusty layer on the surface. While a rusty cast-iron pan is unlikely to harm you, it is still not recommended to cook with it. The rust might add an unpleasant metallic flavour to your food and make cooking more difficult.

Removing Rust from Cast Iron:

• For minor surface rust, rub about 1/3 cup of kosher salt into the pan's surface with a scouring pad or kitchen towel until the spots of rust are removed.
• For more serious cases, start with a vinegar soak. Mix equal parts water and distilled white vinegar and submerge your pan in the solution. Check the pan every 15 minutes and remove it once the rust easily flakes away. This can take anywhere from one hour to eight hours.
• Wash the pan with warm water and a mild dish soap. Clean away any lingering rust with a mildly abrasive sponge.
• Dry the pan immediately and thoroughly with a paper towel. Place the pan on the stovetop over low heat for a few minutes to ensure it is completely dry.
• Add a thin layer of cooking oil to the entire surface of the pan with a cloth or lint-free paper towel.
• Preheat your oven to between 450 and 500 degrees Fahrenheit. Place aluminium foil on the bottom rack of the oven to catch any excess oil. Put your cookware upside down on the centre rack and bake for one hour.
• Turn off the heat and allow the cast iron to cool in the oven.
• Repeat the oiling and baking process a few more times to strengthen the layer of seasoning.

Preventing Rust:

• Always dry your pan thoroughly after use and store it in a dry area.
• If you are stacking multiple cast-iron pans, line each one with a few layers of paper or kitchen towel to prevent moisture from becoming trapped.
• Avoid leaving your pan to soak in the sink or putting it in the dishwasher.
• After washing, dry the pan over medium-low heat on the stove to evaporate any lingering water.
• Coat the pan with a thin layer of seasoning oil after washing and drying.

Is it safe to cook with rusty cast iron?

Cast iron is a popular choice for cookware because of its high quality, affordability, and ability to distribute and retain heat. However, cast iron requires careful maintenance, and one common problem that owners face is the development of rust. So, is it safe to cook with a rusty cast iron pan?

According to the United States Department of Agriculture, rust is not considered food safe and should not be ingested. When cooking with a rusty cast iron pan, there is a chance that some of the rust will end up in your food. However, the quantities are typically so small that they are unlikely to cause harm. In fact, ingesting a small amount of iron can be beneficial for your health and can help prevent anemia.

That being said, it is generally not recommended to cook with a rusty cast iron pan. While it may not pose a serious health risk, rust can add an unpleasant metallic flavour to your food. Additionally, cooking with a rusty pan can make it more difficult to cook as food is more likely to stick to the pan.

If your cast iron pan has developed rust, it is best to remove the rust and reseason the pan before using it again. To remove rust, use dish soap and steel wool to scrub the entire pan until the rust is gone. Rinse the pan with warm water and repeat if necessary. Dry the pan thoroughly with a paper towel and then place it on the stove over medium heat for about five minutes to remove any remaining moisture. Once the pan is completely dry, add a small amount of high-heat cooking oil, such as vegetable or canola oil, to the pan, coating all surfaces. Place the skillet upside down on the bottom rack of your oven and bake at 400 degrees Fahrenheit for an hour. After baking, turn off the oven and allow the pan to cool down before handling.

In summary, while cooking with a rusty cast iron pan is unlikely to cause serious harm, it is not recommended due to the negative impact it can have on the taste and cookability of your food. Instead, take the time to properly remove the rust and reseason your pan to ensure the best cooking experience.

How to season cast iron

Seasoning cast iron is a straightforward process that involves a few simple steps. Here is a detailed guide on how to season your cast iron cookware:

Step 1: Wash and Dry Your Pan

Give your cast iron cookware a good scrub with warm, soapy water. This is especially important if it's a new pan, as you'll want to clean off any residue or contaminants from the manufacturing process or shipping. If your pan has rust or flaking, use something lightly abrasive, like a stiff brush or a scouring pad, to scrub away the rust or flakes under cold water. Dry the pan thoroughly with a towel.

Step 2: Apply a Thin Layer of Oil

Using a paper towel or a cloth, apply a thin, even layer of cooking oil to the entire pan, including the bottom, handle, and outside. You can use a variety of oils, such as vegetable, canola, corn, or flaxseed oil. Make sure to wipe away any excess oil so that the pan feels practically dry to the touch. Using too much oil can cause your pan to become sticky.

Step 3: Heat the Pan in the Oven

Place the oiled pan upside down in the oven. You can place a large baking sheet or aluminium foil on the rack below to catch any oil drips. Heat the oven to between 350-500 degrees Fahrenheit (176-260 degrees Celsius) and bake the pan for about an hour. This process, known as polymerization, will cause the oil to bond to the metal, creating a hard, protective coating.

Step 4: Cool the Pan

Turn off the oven and allow the pan to cool completely before removing it.

Step 5: Repeat as Needed

If your pan is new or has significant rust or flaking, you may need to repeat the oiling and heating process multiple times to build up a strong layer of seasoning. Three to four rounds should be sufficient.

Maintenance

Once your cast iron cookware is seasoned, the best way to maintain the seasoning is to use it regularly. Each time you cook with oil or fat, you'll be adding to the seasoning. You can also re-season the pan occasionally by repeating the steps above.

Additionally, proper cleaning and drying after each use are crucial to maintaining the seasoning and preventing rust. Avoid harsh abrasives and prolonged soaking, as these can damage the seasoning. Instead, use a chain mail scrubber or nylon brush to clean the pan, and always dry it thoroughly, including on the stove over medium-low heat to evaporate any remaining moisture.

With proper care and regular use, your cast iron cookware will develop a natural, non-stick surface that will last for generations.

How to prevent rust on cast iron

Cast iron is a naturally porous material that develops rust when it interacts with water and oxygen. Rust is not food safe and shouldn't be ingested, but it is unlikely that a rusty cast-iron skillet will harm you as the quantities of rust that end up in your food are negligible. However, rust might add an unpleasant metallic flavour to your food and make cooking more difficult. Therefore, it is important to prevent rust from forming on cast iron. Here are some tips to prevent rust on cast iron:

• Avoid soaking cast iron for more than a few minutes. Cast iron should not be left to soak in the sink or put in the dishwasher as this can cause rust to form.
• Dry cast iron thoroughly after washing. Use a towel to dry the pan and then place it on a stovetop burner over low-medium heat for a few minutes to remove any last remnants of moisture.
• Store cast iron in a dry, low-humidity environment. Avoid storing cast iron in damp areas such as under the sink or beside the dishwasher, or in humid areas such as garages, basements, or campers/RVs.
• Use silica gel packets. Silica gel can absorb moisture and take down relative humidity levels, helping to prevent rust spots on cast iron. Place the silica gel packets in and around cast iron skillets, pots, pans, and Dutch ovens.
• Properly season cast iron. The seasoning layer acts as a shield for the iron, protecting it from oxidation and reducing the potential for rust. To test if your cast iron is seasoned properly, hold it at an angle and pour some water across the cooking surface. If the water beads up and runs off quickly, you have a good seasoning layer. If the surface of the pan stays wet, you should re-season it.

What to do with a rusty cast iron pan

Cast iron pans are a great investment for your kitchen. They are high-quality, affordable, and can be used almost anywhere, from the stove to the grill. However, they do require proper maintenance to keep them in good condition. One of the most common issues with cast iron pans is the development of rust. While a rusty cast-iron pan is unlikely to harm your health, it is not recommended to cook with it as it may affect the taste of your food and make the pan more difficult to use. So, what should you do if you find your cast iron pan has developed rust?

First of all, don't panic! Rust development is a common issue and it can be fixed. Start by removing the rust through a deep clean. Use dish soap and steel wool to scrub the entire pan, including all the nooks and crannies, until the rust is gone. Rinse the pan with warm water and repeat if necessary. It is important to note that while cast iron enthusiasts advise against harsh abrasives and hard scrubbing for daily maintenance, in this case, a more thorough approach is needed.

Once the rust is removed, the next step is to ensure your pan is completely dry. Use a paper towel to absorb as much water as possible, and then place the pan on the stove over medium heat for about five minutes to remove any remaining moisture. This step is crucial as cast iron is a porous material and any lingering water can lead to rust reformation.

Now that your pan is clean and dry, it's time to start the seasoning process. Seasoning your pan will create a protective layer that not only makes it non-stick but also helps prevent rust in the future. Add a small amount of neutral high-heat cooking oil, such as vegetable or canola oil, to the pan. Use a clean paper towel to spread the oil and coat every surface evenly, ensuring there is no oil pooling anywhere.

Place the skillet upside down on the bottom rack of your oven and bake at 400 degrees Fahrenheit for an hour. After an hour, turn off the oven and let the pan cool down until it is safe to handle. If you want an even stronger layer of seasoning, you can repeat the oiling and baking process a few more times.

And that's it! Your cast iron pan is now rust-free and ready to use. Remember to always dry your pan thoroughly after use, coat it with a thin layer of oil, and store it in a dry area to prevent rust from forming again. With proper care, your cast iron pan can last a lifetime.

Frequently asked questions