If you properly season and oil an old, rusty cast iron skillet, it can be safe to cook with. The seasoning process creates a protective layer on the skillet's surface, making it non-stick and preventing food from sticking to it. However, it's important to note a few considerations:
Thorough Restoration: Before seasoning the skillet, ensure that you have removed all rust, grime, and pitting to the best of your ability. This will provide a clean surface for the seasoning to adhere to and minimize the risk of contamination.
Seasoning Quality: The quality of the seasoning plays a role in how well the skillet performs and its safety. Make sure to follow proper seasoning techniques, apply multiple layers of seasoning, and ensure each layer is baked thoroughly. This process builds up a durable, non-stick surface and helps protect the skillet from rust.
Oil Selection: Use cooking oils with a high smoke point for seasoning, such as vegetable oil, flaxseed oil, or canola oil. These oils are less likely to break down at high temperatures and form a more durable seasoning layer. Avoid oils with low smoke points, as they can create sticky residues or emit smoke during the seasoning process.
Proper Maintenance: After each use, clean the skillet gently with mild dish soap and water, avoiding abrasive cleaners or metal utensils that could damage the seasoning. Promptly and thoroughly dry the skillet to prevent rust formation. Applying a thin layer of oil after cleaning helps maintain the seasoning and protect the skillet.
By following these guidelines, you can ensure that your seasoned cast iron skillet is safe for cooking. However, always use common sense when assessing the condition of the skillet. If it shows signs of deep pitting, significant damage, or if you have concerns about its safety, it may be best to retire the skillet and invest in a new one.