Using soap on a seasoned cast iron pan can provide several benefits:
Cleaning power: Soap helps to remove stubborn food residues and oils from the cast iron surface more effectively than water alone. It can break down grease and grime, making it easier to clean the pan thoroughly.
Sanitation: Soap has antimicrobial properties that can help kill bacteria and other potentially harmful microorganisms present on the surface of the pan. This can be particularly important if you've cooked raw meats or other foods that carry a higher risk of bacterial contamination.
Odor removal: Soap can help eliminate strong odors that may linger on the cast iron surface after cooking pungent foods like fish or garlic. It can neutralize the odors and leave the pan smelling fresher.
Maintenance: Regularly cleaning your cast iron pan with soap helps maintain its seasoning. Seasoning refers to the layer of polymerized oil that provides a nonstick surface and protects the pan from rusting. Soap removes any built-up residues that can negatively affect the seasoning, allowing you to maintain a well-seasoned pan.
It's worth noting that some traditional advice recommends avoiding soap on cast iron to prevent stripping the seasoning. However, the belief that soap damages cast iron seasoning is a myth. As long as you use a mild dish soap and avoid abrasive scrubbers, soap will not harm the seasoning or the cast iron itself. Properly drying the pan after cleaning and applying a thin layer of oil to the surface can help maintain its seasoning and prevent rust.
Remember, the key to maintaining a well-seasoned cast iron pan is to clean it promptly after use, using gentle scrubbing and mild soap as needed, and then thoroughly drying and applying a thin layer of oil.