Cleaning Rusty Cast Iron: A Step-By-Step Guide

Cast iron pans are versatile and long-lasting, but they can be high-maintenance. Cast iron is susceptible to rust, which occurs when the protective layer of carbonized oil, or seasoning, is compromised. Rust can be caused by exposure to moisture, such as by soaking the pan, putting it in the dishwasher, or letting it air dry. However, it is possible to restore a rusty cast iron pan to its former glory. The process involves removing the rust, cleaning the pan, drying it, and re-seasoning it. This typically includes scrubbing the pan with an abrasive tool, rinsing it, drying it, and then coating it with oil and baking it in the oven. With proper care and maintenance, cast iron pans can last a lifetime.

Soak in a vinegar and water solution

To clean a rusted cast iron pan, you can soak it in a vinegar and water solution. This is an effective way to remove rust and is particularly useful for pans with a thick layer of rust.

To do this, fill your sink with equal parts water and vinegar. You need enough of this solution to fully submerge your cast iron pan. Be careful not to overflow the sink, as the water level will rise when you add the pan. The amount of vinegar you use will determine how long it takes for the rust to break down. The more vinegar you use, the less time it will take.

Allow the pan to soak for one to two hours. Depending on how tough the rust is, you may need to wait up to eight to ten hours. Most rust will soften within one to two hours, so after about an hour, you can try to scrub the pan to see if the rust is coming off easily.

Once the rust has softened, use a scrubby sponge, scrub brush, or steel wool to remove it. You can then rinse the skillet with water, ensuring that all the rust is gone. Dry the skillet completely with paper towels or a dish towel.

Finally, you will need to reseason the cast iron pan. This can be done on a stovetop or in the oven.

Scrub with steel wool

To clean a rusted cast-iron pan with steel wool, start by filling your sink with a 1:1 mixture of water and vinegar. Ensure there's enough liquid to fully submerge your cast iron pan. The longer you let the pan soak, the easier it will be to scrub off the rust. Depending on the toughness of the rust, you may need to wait up to 8–10 hours. However, most rust will soften within 1–2 hours.

After letting the pan soak, scrub the rusty sections with fine steel wool until the area returns to raw cast iron. Rinse the pan with water, and keep scrubbing until no traces of rust remain.

Once you've removed all the rust, thoroughly dry the pan with paper towels or a clean dish towel. It's important to ensure the pan is completely dry before moving on to the next step. You can place the pan on the stovetop over low heat for a few minutes to make sure it's entirely dry.

After drying, apply a very thin, even layer of cooking oil to the pan's entire surface, including the bottom and handle. Use just enough oil to coat the surface, avoiding excess that may cause stickiness.

Finally, place the pan upside down on the top rack of your oven. Place a sheet of aluminum foil or a foil-lined baking sheet on the bottom rack to catch any oil drips. Heat the cast iron for about an hour at 350–500°F. Then, turn off the heat and let the cast iron cool down before using it again.

Wash with soap and water

To clean a rusted cast-iron pan with soap and water, follow these steps:

Firstly, fill your sink with a mixture of equal parts water and vinegar. Ensure there is enough liquid to fully submerge your cast iron pan. The vinegar will break down the rust, but it may take up to eight hours, so be sure to keep checking. It is very important to remove the pan from the solution as soon as the rust has gone, as the vinegar can cause irreversible pitting.

Once the rust has been removed, scrub the pan with mild dish soap and warm water. You can use a scouring pad, an abrasive sponge, or fine steel wool for this step. Scrub away all the rust, then immediately dry the pan with a clean dish towel or paper towel to prevent future rusting. You can even place the pan on the stove over low heat to help any remaining moisture evaporate.

Now your pan is clean and dry, it's time to re-season it. Add a dollop of vegetable oil to the interior and wipe it around with a paper towel to fully coat the surface. Continue wiping away the oil with fresh paper towels until no oil is visible.

Dry thoroughly

Drying your cast iron pan is a crucial step in the cleaning process, as cast iron is highly susceptible to rusting when exposed to oxygen and water. There are several effective ways to dry your cast iron, ensuring that no future rusting occurs.

Firstly, it is important to note that you should never let your cast iron air-dry. Instead, use a lint-free towel, such as a microfiber cloth, to thoroughly wipe down the entirety of the pan—the top, bottom, and sides. You can also use paper towels, but be sure to use enough pressure to dry the pan without scrubbing it. If you're unsure if your cast iron is completely dry, you can always put it back on the stovetop or in a clean oven at a low temperature to evaporate any remaining water.

Another effective method for drying your cast iron is to place it on the stovetop over a low flame. After washing your cast iron, wipe out most of the water with a towel or paper towel, then place the skillet over a medium flame for about 5 minutes. This method ensures that any remaining moisture is removed and also preserves the seasoning on your skillet.

Additionally, you can dry your cast iron in the oven. Preheat your oven to a low temperature, then place your cast iron inside for a few minutes to ensure it is completely dry. This method is more time-consuming but is a good option if you plan to season your cast iron in the oven afterward.

Remember, it is essential to dry your cast iron thoroughly after each cleaning to prevent rust and maintain the integrity of the seasoning.

Re-season with oil

Once your cast iron pan is clean and dry, it's time to re-season it. Here's a step-by-step guide:

Preheat the oven:

Preheat your oven to between 350°F and 500°F. The higher the temperature, the better the seasoning. Place a sheet of aluminium foil on the bottom rack of the oven to catch any oil drips.

Coat the pan with oil:

Using a cloth or lint-free paper towel, add a thin layer of cooking oil to the entire surface of the pan, including the handle. Go easy on the oil—just use enough to coat the surface, not enough to drip or run.

Place the pan in the oven:

Place the oiled pan upside down on the centre rack of the preheated oven. This will help prevent oil from pooling on the cooking surface.

Bake for an hour:

Bake the pan for one hour. Then, turn off the heat and allow the pan to cool completely in the oven. This allows the seasoning to cure and adhere to the iron.

Repeat as needed:

If your pan is in bad condition, you may need to repeat the seasoning process several times to build up a non-stick base coat. Simply rub oil onto the cool pan and bake it upside down for one hour at 500°F, letting the pan cool in the oven.

Tips:

• You can use any type of oil for seasoning, but try to find a high smoke-point oil if you can.
• It's important to move quickly from drying the pan to seasoning it, as rust can develop very quickly on a clean, dry pan.
• You only need to rub oil into a hot pan the first time; any further coats of oil go on a cool pan.

Frequently asked questions