Cast iron has a reputation for being difficult to maintain. It is not, but the maintenance is specific, and doing the wrong thing. Particularly putting it in the dishwasher or leaving it wet. Undoes the seasoning quickly. Here is a plain explanation of what seasoning is and how to keep it in good condition.
What seasoning actually is ¶
Seasoning is a layer of polymerised oil baked onto the surface of the iron. When oil is heated to its smoke point and beyond, it breaks down and bonds to the metal in a thin, hard layer. Multiple layers of this build up over time into a smooth, dark, non-stick surface. The pre-seasoning on the Iwate cast iron skillets we sell is done with rice bran oil, which has a high smoke point and is well suited to the process. When you cook with fat in the pan, you are adding to this layer.
How to maintain it ¶
After each use, wash the pan with hot water and a stiff brush. A small amount of dish soap is fine. The idea that soap destroys seasoning is a myth that applies to old lye-based soaps, not modern detergents. Dry the pan immediately and thoroughly. The fastest method is to put it on a low burner for two minutes after washing. While it is still warm, apply a very thin coat of oil. Rice bran, vegetable, or flaxseed. And wipe off almost all of it with a cloth. What you want is a barely-there film, not a visible coat.
What to do when seasoning fails ¶
If the pan develops rust spots, the seasoning has been compromised. Scrub the rust off with steel wool, wash the pan, dry it completely, and re-season from scratch. To re-season: apply a thin coat of oil to the entire pan including the exterior, place it upside down in an oven at 230 degrees Celsius for one hour, then let it cool in the oven. Repeat two or three times. The pan will not look as dark as a well-used pan immediately, but it will build up again with cooking.
What not to do ¶
Do not put cast iron in the dishwasher. Do not leave it soaking in water. Do not store it with the lid on if there is any moisture inside. The enclosed space will cause rust. Do not cook acidic foods like tomatoes or citrus in a new pan before the seasoning is well established; acid strips seasoning. After the first year of regular use, the seasoning is enough to handle occasional acidic cooking without damage.
The Iwate cast iron skillet is available in 24 cm. A 20 cm version is in development and will be listed later in 2026. Spare lids and handles are available separately through the contact page.