I advise you to not put your cast iron in the dishwasher. The detergent in the dishwasher will remove your seasoning, and during the drying process, the cast iron pan will start to rust. But really, all it will do is remove the seasoning, and it might rust slightly. Everything can be fixed.

Why is it bad?

Although cast iron is tough, there are two things that can ruin a cast iron pan. One is soap.

A dishwasher uses soap and hot water to clean the cookware. The soap helps to remove fat and oil. This is exactly what is in the seasoned layer of your pan.

And putting it in the dishwasher will strip the seasoning off your pan.

If you do remove the seasoning coating, it’s no big deal though. You can re-season it again.

The other risk is rust.

If your cast iron is in the dishwasher, it is not likely to get dried perfectly. With the amount of water involved in the cleaning, when the dishwasher does the dry cycle, it is likely to leave some moisture, and the pan or skillet will start to rust.

But again, if it does rust, it’s not a big deal. You can remove the rust and season the cast iron again.

I don’t recommend using the dishwasher, but it is possible and you will be able to restore your cast iron. Don’t panic.

Cast iron seasoning.

Seasoning your cast iron is almost like creating a natural nonstick layer. It helps food have an easy release when cooking.

The layer of seasoning is made up of oils and fats that have formed a layer over cast iron skillet. This dark layer creates a patina and protecs your cookware and will help it last for generations.

Every time you cook, you must add a small bit of seasoning. This is best done with vegetable oil on a paper towel and rub it all over the cast iron and then put over a gentle heat to bake in the oil.

Cast iron rust?

A cast iron pan is made up of a mix of pig iron, steel and various alloys. Without the layer of seasoning, the pan is more likely to rust. The seasoning protects the cast iron from moisture, which is what causes the rust.

But even if you do get your cast iron pan rusty, there is no need to throw it way. You can regain that beautiful well-seasoned pan again with just a little elbow grease.

How you should clean your cast iron?

The best way to clean your cast iron pan or skillet is to wash ut by hand with no soap. Use a very soft abrasive pad to remove the stuck-on food. Firm enough to remove the baked-on food but not firm enough to really scratch the surface. Once you have washed off all the food then dry it immediately and if possible put it over heat to burn off all the remaining moisture.

I also recommend trying a cast iron chain mail scrubber, it has just the right amount of abrasiveness to clean the pan from dirt but not to remove the seasoning.

How to fix your cast iron after the dishwasher

Replace your seasoning

If you have removed all the seasoning from your cast iron then you can slowly add it back.

To season your pan, choose a vegetable oil and put it on some paper towel. Thoroughly wipe this all over the cast iron then put the cast iron over a low heat to bake the oil into the pan or skillet.

You can also do this in the oven. Wipe the vegetable oil all over the pan and put it upside down in the the oven at 450-500 degrees F for about 1 hour. Be careful with this method as you don’t want to create a fire hazard.

Remove the rust

If your cast iron pan has become rusty after you put your iron pan in the dishwasher.

Have not fear, do not panic. You can fix this.

Make sure the pan is clean. Soak it and wash it with warm dish soap, don’t worry about removing the seasoning at this point as we are concentrating on the rust. You can re-season it after.

Use steel wool to scrub the pan all over to remove the surface layer of rust. You may find that you have to scrub hard at times.

Make sure all the flaky rust has been removed and and then wash it again with some hot soapy water.

Dry it thoroughly with a lint free microcloth and then put it over some heat to remove all the moisture.

Then replace the seasoning as described above.

In conclusion

I would not recommend putting your cast iron in a dishwasher. Especially if it is someone else’s, they would not be too happy with you.

But, cast iron is such a tough beast, you really can’t ruin it. You’ll just have to fix it like I have described above. It’s your time you have to consider. That’s the only cost really.