The conventional advice of not washing cast iron skillets with soap stems from the belief that soap will strip away the seasoning—a layer of polymerized oil that forms on the surface of the pan after repeated use and provides the non-stick properties. The seasoning is crucial for maintaining the cast iron's performance and preventing rusting.
However, this advice has been somewhat exaggerated, and it's not entirely accurate. While it's true that harsh soaps and abrasive scrubbing can damage the seasoning, using a small amount of mild dish soap to clean a seasoned cast iron skillet is generally safe and won't ruin the seasoning entirely.
The key is to use a gentle touch and avoid harsh chemicals or abrasive scrubbers. Here's how to clean a seasoned cast iron skillet properly:
Cool down the pan: Allow the cast iron skillet to cool down slightly after cooking.
Use mild dish soap (optional): If needed, you can use a small amount of mild dish soap and warm water to clean the pan. Gently scrub the surface with a soft sponge or brush. Avoid using harsh scouring pads or metal brushes, as they can damage the seasoning.
Rinse and dry thoroughly: Rinse the pan under warm water and make sure to remove all the soap. Dry the skillet thoroughly with a towel immediately after washing to prevent rust.
Apply a thin layer of oil: To maintain or restore the seasoning, apply a thin layer of cooking oil (such as vegetable oil or flaxseed oil) to the entire surface of the pan. You can do this by using a paper towel and wiping off any excess oil.
Regarding the pan retaining flavors, seasoned cast iron can absorb some flavors from strongly aromatic or acidic foods, especially if the seasoning is not well-established or has been damaged. This is why some people have dedicated cast iron pans for specific types of dishes, like one for sweets and another for savory dishes. However, with regular use and proper seasoning, the pan's surface becomes more inert and less likely to retain flavors over time.
If you ever notice any strong flavors lingering in your cast iron skillet, you can restore the seasoning by thoroughly cleaning it and re-seasoning the pan.
In summary, washing a seasoned cast iron skillet with a small amount of mild dish soap is generally safe, but it's essential to be gentle and avoid harsh scrubbing. Regular seasoning and proper care will help maintain the non-stick surface and reduce the likelihood of flavors being retained in the pan.