No, it is not safe to use a cast iron skillet after washing it in a dishwasher and drying it on a high heat setting. Cast iron skillets are not designed to be cleaned in a dishwasher or exposed to high heat for extended periods. Doing so can cause significant damage to the skillet and diminish its performance.
Here's why:
Rust formation: Cast iron is prone to rust if not properly cared for. Using a dishwasher can strip away the skillet's seasoning (a layer of polymerized oil that provides a non-stick surface and protects against rust) and expose the bare metal to water, leading to rust formation.
Soap damage: Most dishwashers use harsh detergents, which can also break down the seasoning and damage the cast iron surface.
Heat damage: Dishwashers use high-temperature water and drying settings, which can cause warping and cracking in cast iron cookware.
To maintain your cast iron skillet properly:
Hand wash only: Clean your cast iron skillet by hand with hot water and a soft brush or sponge. Avoid using soap, especially if the skillet is well-seasoned. If you need to remove stubborn food residues, you can use a small amount of mild soap, but always rinse and dry it thoroughly afterward.
Avoid soaking: Do not soak your cast iron skillet in water for extended periods, as this can lead to rust.
Dry thoroughly: After washing, dry the skillet completely using a towel, and then place it on the stove over low heat for a few minutes to ensure it is entirely dry.
Re-seasoning: If the skillet's seasoning has been damaged, you can re-season it by applying a thin layer of vegetable oil and baking it in the oven at a low temperature.
With proper care, a cast iron skillet can last for generations and provide excellent cooking results. Remember that the more you use and care for it, the better its seasoning and non-stick properties will become.