Cooking with an old, rusty, pitted cast-iron skillet can be risky and may not be safe even if you season it well. Here's why:
Rust and pitting: Rust and pitting can weaken the integrity of the cast iron, making it more prone to breakage. Pitted surfaces can also make it difficult to create a smooth, even seasoning, leading to potential hot spots and uneven cooking.
Contaminants: Rust can introduce harmful contaminants into your food, which can be hazardous to your health. Even if you season the skillet, it may not fully protect against these contaminants leaching into your meals.
Uneven heating: Rust and pitting can lead to an uneven heating surface, causing some areas of the skillet to heat more than others. This can result in unevenly cooked food and might even lead to burning in certain spots.
Difficult to clean: Cleaning an old, rusty skillet can be challenging, and you risk introducing harmful substances or bacteria into your food during the cooking process.
While seasoning a cast-iron skillet can create a non-stick surface and help protect the iron from further rusting, it is not a solution for addressing existing rust and pitting. If your skillet is in bad condition, it's generally better to retire it and invest in a new one.
If you have a cast-iron skillet that's in good condition but needs re-seasoning, you can do so by scrubbing off the rust, thoroughly cleaning it, applying a thin layer of vegetable oil or other suitable oils, and then baking it in the oven to create a new seasoning layer. Regular maintenance and proper care of a cast-iron skillet can help it last for generations and provide safe and enjoyable cooking experiences.