How to Clean Black Residue off Cast Iron Skillet

A cast-iron skillet is a timeless kitchen staple that is built with the goal of remaining durable and reliable for many years to come. Longevity will only come to fruition if the skillet is properly cared for and maintained. 

A new cast-iron skillet has a black coating across its entire body that will help prevent it from rusting over time. However, untouched burnt foods and oil tend to stick to the bottom of the pan after cooking. It’s important to take note of the difference between the original black coating of the skillet and leftover black residue. 

Certain oils, like olive oil, have a lower smoke point and tend to overheat quickly. This can cause oil deposits to be left on the bottom of the skillet, eventually turning into a darker colored residue. The same goes for burnt foods. If oil is not used, most likely pieces of cooked food will remain on the skillet when exposed to high heat. Overall, it’s a no-win situation, where a buildup of residue is inevitable. 

Learning the proper way to clean your cast-iron skillet, and therefore remove any leftover residue will help to extend the life of the pan. Here are the various tips and methods to clean black residue off of a cast-iron skillet.

Baking Soda, Salt or Soap

Leaving residue on a cast iron skillet can be damaging to the coating, eventually breaking down the protective layer and causing it to rust over time. That’s why it’s vital to clean it after each use. One way to do that is by spreading baking soda, salt, or soap across the bottom of the skillet. These are common household items and should be easily accessible to get at any convenience or grocery store or may even already be available in your kitchen. 

This method to clean a cast-iron skillet is quite simple and can be done in a few simple steps. Start by evenly sprinkling either baking soda or salt onto the skillet’s base. Both of these ingredients will work to remove any harsh carbon deposits, which results from overcooked foods. Then add in some luke-warm water and dish soap. The soap will make its way through the oil, helping to remove any of the burnt debris. 

Combine the mixture and scrub the skillet. Once the pieces of residue start to become detached from the pan, rinse it with medium-hot water. Make sure it’s not overly hot or close to boiling. Repeat the scrubbing process once more to ensure every particle is removed.  

Finally, rinse the skillet through and pat dry with a paper towel. You don’t want to leave it to air dry or else pieces of the coating can begin to disintegrate. To ensure the skillet is completely dry, place it in the oven for 20 minutes after toweling drying.

Boiling Water

Another way to clean black residue off a cast iron skillet is to use boiling hot water and a flat-ridged kitchen utensil. This method is simple to perform and requires limited steps and ingredients. However, it works best on burnt foods and may not fully remove leftover oils. This is a good option if you plan to cook without the use of olive oil or other oily bases. 

The first step is to scrub off any food that is not thoroughly stuck to the bottom of the pan. Make sure to use a non-abrasive scrub brush or the skillet could be scratched and subjected to further damage during future uses. 

Once you feel that you have scrubbed off all the pieces that can be removed manually, it’s time to evenly fill the pan with water until every trace of residue is completely covered. Place the skillet on your stovetop and bring the water to a boil. 

Once the water has reached a boiling temperature, remove the skillet from the heat. Take a smooth-facing spatula and begin grinding off any additional remnants. 

Repeat this entire process until all food particles are extracted. Finish up by rinsing the cast iron skillet with warm water and wipe it down until it’s completely dry. Again, you can place it in the oven for assurance.

Vinegar and Water

Next up, is the vinegar and water approach. Vinegar is a versatile product that can be used for various purposes, including cleaning black residue off of a cast iron skillet. Because vinegar is so acidic, it will work to remove leftover food and oil, while also getting rid of any unwanted rust buildup.

You can start by clogging your sink’s drain and filling it up with equal parts water and white vinegar. Completely submerge your skillet into the mixture and let it soak for a total of one hour. 

After soaking, remove the pan and begin to scrub it down. Let the skillet soak for an additional hour and scrub it down once more. After the pan has been double soaked, any remaining residue should easily come off. Although this method doesn’t take much physical effort, it can take up a good chunk of time. That’s the one downside. 

Do a final rinse of the skillet and dry it completely.

Self-Cleaning Options

Finally, you can let the cast iron skillet self-clean. This is the easiest approach that will take up hardly any time or effort. All you need is an oven. 

The oven’s high temperatures are able to wash away layers upon layers of burnt food and oil until the pan is squeaky clean. You will first need to move a rack to the bottom of the oven. Then place the skillet faced down. This will allow particles to fall from the skillet onto the oven’s base. 

Set your oven to its self-cleaning cycle and watch as the residue simply lifts off the pan. You can repeat this process until the skillet is fully clean. Remember to wait until the skillet isn’t hot anymore before taking it out of the oven. 

As an extra precaution, scrub the bottom to ensure there is no residue leftover. You can then rinse it with water and pat dry.


The tips listed above all work great to clean any black residue off of a cast-iron skillet. Additionally, there are a few ways to prevent the buildup of this residue from happening in the first place. This will save you time further down the road when your skillet needs a big clean. 

The first tip may be a given, but you want to try to avoid burning or overheating oils. This is essentially how a black layer of debris gets on your skillet in the first place. You can do this by using certain oils that have a higher smoke point, like avocado oil, almond oil, or sunflower seed oil. 

Also, if you notice food is burning, you can try quickly pouring some additional oil into the skillet. This will help to alleviate the damage. 

Finally, add oil to the skillet after every clean. Vegetable oil is the preferred type in this case. You only need a tiny bit, so it forms a thin, even layer across the bottom. Then place it in the oven for around one hour. This will help protect the black coating from breaking down and rusting over time.