Reviving The Relic: Restoring Your Rancid Cast Iron Pan

Cast iron pans are tough and can last for generations, but they do need to be maintained. If your cast iron pan has gone rancid, it's likely due to oil or fat residue being left in the pan. The good news is that it can be rescued! The first step is to remove any leftover food debris and scrub the pan to get rid of any rust. Next, you'll need to restore the cast iron seasoning by coating the pan with a thin layer of cooking oil and placing it in the oven upside down for an hour at a high temperature. This process may need to be repeated several times to ensure the seasoning takes hold. Once your pan is restored, be sure to clean, dry and store it properly to prevent rust from returning.

Soak in vinegar

If your cast iron pan has gone rancid, it's likely that rust has developed due to exposure to moisture. To fix this, you can try soaking it in vinegar, a process that will dissolve the rust. Here's how to do it:

Step 1: Soak in Vinegar

Firstly, mix equal parts water and distilled white vinegar in a container large enough to completely submerge your cast iron pan. It's important that the container is big enough to cover the entire pan, including the handle. Place the pan in the solution and keep an eye on it, checking it every 15 minutes or so. The vinegar solution will start to fizz as it works to dissolve the rust. The time it takes for the rust to be removed will vary, but it can be anywhere from an hour up to eight hours. It's important to not leave the pan in the solution for too long, as once the rust is gone, the vinegar can start to damage the original cast surface of the pan.

Step 2: Remove from Solution

Once the rust has easily flaked away and can be removed, take the pan out of the solution and rinse it with running water. You may notice a thin layer of flash rust appear at this point, but don't worry.

Step 3: Make a Slurry

To remove any remaining rust, make a slurry by mixing a cleanser like Bar Keepers Friend with a couple of tablespoons of water in the pan.

Step 4: Scrub with a Stainless Steel Scrubber

Use a stainless steel scrubber to scrub any remaining rust off the pan. Be sure to wear rubber gloves to protect your hands.

Step 5: Rinse, Dry, and Re-season

After scrubbing, rinse the pan with water and dry it thoroughly. You can place the pan over low heat on the stovetop or in an oven set to 200-300 degrees Fahrenheit to ensure all moisture is gone. Once dry, follow the steps to re-season your cast iron pan.

Re-seasoning:

• Preheat your oven to between 450 and 500 degrees Fahrenheit.
• Apply a thin layer of cooking oil or seasoning spray to the surface of the pan, inside and out. Use a paper towel to wipe the surface until no oil residue remains.
• Place the pan upside down in the oven, with a baking sheet or aluminium foil on the rack below to catch any drips.
• Bake for one hour, then turn off the heat and let the pan cool in the oven.

Your cast iron pan should now be rust-free and ready to use!

Scrub and wash

Scrubbing and washing your cast iron pan is an important step in the process of restoring it to its former glory. After all, you want to remove any lingering rust and ensure your pan is clean before you start the re-seasoning process.

If you're dealing with minor surface rust, you can use a scouring pad, kitchen towel, or mildly abrasive sponge to scrub away the rust. Sprinkle some kosher salt or use a mild dish soap and warm water to help remove the rust. For more stubborn rust, you may need to soak your pan in a vinegar solution before scrubbing. Create a mixture of equal parts water and distilled white vinegar and submerge your pan, checking it every 15 minutes. Remove the pan from the solution once the rust easily flakes away. Be careful not to soak the pan for too long, as the vinegar can start to eat away at the original cast surface.

Once the rust is gone, give your pan a thorough wash with mild dish soap and warm water. Use a mildly abrasive sponge, such as a green scrub pad, to remove any remaining rust or debris. Always use warm water to clean your cast iron to prevent warping or cracking from a sudden change in temperature. Dry your pan immediately and thoroughly with a kitchen or paper towel. You can even place it on the stovetop over low heat for a few minutes to ensure it's completely dry.

At this point, your cast iron pan should be free of rust and ready for the re-seasoning process. Remember, it's important to be thorough during the scrubbing and washing step to ensure the best results for your pan's restoration.

Reseason the pan

Reseasoning a cast-iron pan is a straightforward process, but it will take some time and effort. Here is a detailed guide on how to do it:

First, you need to remove any remaining food debris from the pan. Use a pan scraper or a metal spatula to remove stuck-on food. If the food is particularly stubborn, add a little water to the pan and boil it for a few minutes before trying to scrape it off again. Make sure to dry the pan thoroughly after removing the food.

Next, you will need to remove the old seasoning. This can be done by scouring the surface with warm, soapy water and a metal scouring pad. Rinse and dry the pan thoroughly. If there is stubborn rust, you may need to use steel wool to scrub it off.

Once the pan is clean and dry, it's time to apply a new layer of seasoning. Start by preheating your oven to between 450-500°F (230-260°C). While the oven is heating, use a cloth or paper towel to rub a thin layer of cooking oil onto the entire surface of the pan, including the inside and outside. Use a neutral cooking oil with a high smoke point, such as vegetable, grapeseed, canola, or sunflower oil. Make sure the oil is thinly and evenly coated, with no visible runs.

Place the pan upside down on the top rack of the oven and place a sheet of aluminium foil or a baking sheet on the bottom rack to catch any drips. Bake the pan for an hour, then turn off the oven and allow the pan to cool down naturally. If there are any spots you missed, repeat the process of oiling, baking, and cooling until you are happy with the result. You may need to turn on the exhaust fan or open a window during this process to avoid smoke or odours.

Finally, your pan is ready to be used again! From now on, make sure to maintain your pan by cleaning and drying it promptly after each use and coating it with a thin layer of oil. With proper care, your cast iron pan should last a lifetime.

Preventing rancidity

Cleaning:

• Avoid soaking your cast iron pan in water or leaving it in a wet sink, as this can lead to rust. Instead, clean your pan with a mild dish soap and warm water after each use.
• Use a mildly abrasive sponge, such as a green scrub pad, or a scouring pad to remove any food residue or rust spots.
• Avoid using metal scrubbers or detergents as these can damage the seasoning.
• If you need to remove tough, stuck-on food, use a pan scraper or metal spatula first. If that doesn't work, add a small amount of water to the pan and boil it for a few minutes before scraping again.
• If your pan has a lot of rust or caked-on gunk, you can try a vinegar soak. Mix equal parts water and distilled white vinegar in a bucket or deep foil pan, ensuring the entire pan is submerged. Check the pan every 15 minutes and remove it once the rust flakes away, which can take up to eight hours. Be careful not to leave the pan in the vinegar solution for too long, as it can start to eat away at the original cast surface.
• After cleaning, always dry your cast iron pan immediately and thoroughly with a kitchen or paper towel.

Storage:

• Ensure your cast iron pan is completely dry before putting it away.
• Store your pan in a low-humidity spot, away from moisture-prone environments like cabinets near dishwashers or open cabinets in humid locations.
• If stacking multiple cast-iron pans, line each one with paper towels or breathable pan separators to prevent moisture buildup.

Other Tips:

• If you're not going to use your cast iron pan for an extended period, consider coating it with a thin layer of food-grade mineral oil to prevent rust. Just be sure to wash the oil off before using the pan again.
• Re-season your cast iron pan regularly to maintain its non-stick properties and protect against rust. The process involves scrubbing away any loose flakes, coating the pan with a thin layer of cooking oil, and baking it in the oven at a high temperature for an hour.

Removing rust

Once you've removed the rust, wash the pan with warm, soapy water. This step may remove some of the seasoning, but that's okay because you're going to re-season the pan. Dry the pan thoroughly with a paper towel or lint-free cloth. You can even place it on the stovetop on low heat for a few minutes to ensure it's completely dry.

Now it's time to re-season the pan. Add a very thin layer of cooking oil to the entire surface of the pan with a cloth or lint-free paper towel. Place the pan upside down on the center rack of an oven preheated to 450-500°F. Put aluminum foil on the bottom rack to catch any excess oil. Bake for one hour, then turn off the heat and allow the pan to cool in the oven.

Frequently asked questions