How To Clean Black Residue Off Cast Iron Skillet

Black residue on cast iron is simply frustrating. You go to cook your food, and it just gets coated in black stuff. The black residue is most likely food that’s left over from the last cook, and it’s managed to keep hold of the cast iron during cleaning. However there are a few ways to get rid of black residue on cast iron skillets.

Did you know vinegar is an acid that breaks down anything alkaline and since most black residue is from charred food or oils, these are alkaline which allow the vinegar to act aggressively on them.

In this article, I’ll be covering exactly how to clean black residue off your cast iron skillet, and how to prevent it from happening again.

How To Remove Black Residue Off Cast Iron Skillets

There are a few methods when it comes to cleaning black residue off a cast iron skillet. Personally I prefer to use a self cleaning oven first, and then move onto the more traditional methods to do a final clean.

Below are all the methods I use to clean black residue off my cast iron skillet.

Remove black residue off cast iron skillets with a self cleaning oven

This method I love for cleaning cast iron cookware, because self cleaning ovens reach a temperature of around 500 degrees Celsius, and cast iron cookware can tolerate that kind of heat.

Self cleaning ovens work by using extremely high temperatures that oils, food residue and carbon residue cannot withstand and they breakdown.

To clean the black residue on cast iron skillets using this method, simply place the cast iron skillet upside down in the oven, turn the self cleaning cycle on, and leave it until the cycle has finished.

This should normally take a few hours.

Remove black residue off cast iron skillets with dish soap & kosher salt

Using soap and salt to clean cast iron pans is a traditional method, the soap acts as a degreaser, and the salt is the abrasive.

Start by adding dishwashing soap to the cast iron skillet and use a sponge to scrub it all over. While that’s taking effect and breaking up the black residue, fill half a cup with salt.

After 10 minutes, pour the salt into the cast iron skillet and start scrubbing with the sponge. This should remove any black residue on your cast iron pan.

Once you feel like all the black residue on the cast iron pan is gone, rinse it thoroughly with some warm water, scrub with the sponge if needed. You want to clean any of the cleaning mixture off.

Now dry with some paper towels, you need to remove all the moisture by doing this as cast iron rusts very easily.

Finally, just to be safe, heat the cast iron skillet on the stovetop to evaporate any left over moisture.

Remove black residue off cast iron skillets with vinegar & baking soda

Vinegar is amazing for cleaning, especially cleaning black residue off cast iron skillets. It’s high acidity can break down even the strongest of bonds since residue is mostly alkaline and acid breaks down anything alkaline.

To use this method, simply pour some vinegar into your cast iron skillet and boil the vinegar. Once the vinegar has boiled, add some baking powder. You should see a reaction occur.

Let the vinegar and baking soda mixture cool down, and start to scrub away at the black residue. This should clean it straight off.

Now rinse the cast iron skillet under some warm water, and again place it back on the stovetop to evaporate any moisture left over to prevent your cast iron pan from rusting.

What is the black residue on a cast iron skillet?

Black residue is normally the seasoning on a cast iron pan. The seasoning reacts to the iron to create a visible black layer of seasoning.

Other causes can be down to burnt food simply building up in the pan and over time creating a layer of burnt on food.

Is black residue on a cast iron pan harmful?

Over time, black residue will always build up in your cast iron pan due to seasoning and burnt food. This is unavoidable.

The black residue from seasoning is completely harmless, and it shouldn’t come off into your food anyway as it’s bonded against the cast iron cookware.

If the black residue is from burnt on food, then it’s perfectly safe to cook in and is very unlikely to increase your risk of cancer. However it will add a charred taste to your food and ruin the flavor, so it’s best to keep your pan clean from any burnt food.

How To Prevent Black Residue on a cast iron skillet

Preventing a build up of black residue will not only save you time and effort, but it will protect your cast iron cookware.

Since black residue is mainly due to carbonized/polymerized oils and burnt food, it’s quite easy to avoid.

Keep it clean – Cast iron pans tend to get very hot, and this causes food and greases to burn onto the bottom of the pan. This is mainly what causes black residue. Ensure you are cleaning your pan with warm water after every use.

Reseason – If you have started getting a small build up, simply clean the current layer of seasoning off and re-season it. This will prevent a large build up of black residue, saving you both time and effort in the future.