No, do not put a cast iron skillet in the dishwasher. The long soak, the strong detergent and the wet heat strip the seasoning, and bare iron can start to rust within hours.
One cycle will not ruin the pan. It will leave it dull, gray or spotted with orange, and food will stick until you fix it. The iron underneath is fine. The seasoning is the part that is lost.
What seasoning is
Seasoning is a thin layer of oil baked onto the iron until it hardens. It makes a cast iron pan slick, and it keeps water off the metal. A dishwasher attacks both jobs at once. The detergent breaks down the oil layer, and the drying cycle leaves the bare metal damp.
This is why care guides for pre-seasoned pans, from the makers and from owners, say to wash by hand.
How to clean it instead
Hand washing takes about two minutes and is easier than it sounds.
- Wash the pan while it is still warm, with hot water and a brush or a non-scratch sponge.
- Use a small drop of dish soap if you want. Modern seasoning handles it. Do not soak the pan.
- For stuck food, scrape with a pan scraper, or simmer a little water in the pan for a few minutes.
- Dry it right away with a towel. Then set it on a low burner for a minute to drive off the last moisture.
- Rub in a few drops of cooking oil with a paper towel, then wipe off the extra. The pan should look dry, not greasy.
Skip long soaks and skip the dishwasher. Those are the two habits that do the most damage.
If someone already ran it through
Do not throw the pan out. Re-season it.
- Scrub off any rust with steel wool or a stiff brush until you see bare gray iron.
- Wash it, rinse it and dry it fully.
- Rub a very thin coat of oil over the whole pan: inside, outside and the handle. Wipe it until it looks almost dry. Too much oil bakes into a sticky film.
- Put the pan upside down on the middle oven rack, with a sheet of foil on the rack below to catch drips.
- Bake at 450 to 500 degrees F for one hour. Turn the oven off and let the pan cool inside.
One round gives a base coat. Repeat it two or three times for a smoother finish. After that, regular cooking with fats builds the rest.
Exceptions
Enameled cast iron is a different product. The enamel coating can often go in the dishwasher, but most makers still advise hand washing to protect the finish and the rim. Check the care sheet that came with yours.
An old pan with no seasoning left, such as a flea market find, needs the same re-seasoning steps before first use.
A pan to start with
If you are buying your first one, a pre-seasoned skillet saves the first round of work. A 12 inch pan is a common size for a family: it fits four chicken thighs or a full batch of cornbread. It is heavy, so skip it if you have wrist pain or want a pan you can lift with one hand.
