The black stuff that comes off your cast iron pan is likely the seasoning or the polymerized oil layer. Cast iron pans are seasoned by applying a thin layer of oil and then heating it at a high temperature. This process creates a natural non-stick surface and protects the pan from rusting.
Over time and with regular use, the seasoning on the cast iron pan can wear down or become damaged. As a result, some of the black residue may come off the pan while cooking or cleaning. This is normal and nothing to be concerned about.
To maintain and improve the seasoning of your cast iron pan, you can follow these tips:
After each use, clean the pan with warm water and a soft sponge. Avoid using soap, as it can strip away the seasoning.
Dry the pan thoroughly with a clean cloth or paper towel to prevent rusting.
Apply a thin layer of cooking oil or solid shortening to the surface of the pan. You can do this by rubbing the oil all over the pan with a paper towel.
Heat the pan upside down in an oven at a temperature between 350°F (175°C) to 400°F (200°C) for about an hour. This will help the oil polymerize and create a new layer of seasoning.
Allow the pan to cool in the oven before taking it out.
By regularly maintaining and re-seasoning your cast iron pan, you can keep it in excellent condition and prevent excessive buildup of black residue. Remember that a well-seasoned cast iron pan becomes more non-stick over time and can be a versatile and durable tool in your kitchen.