Metallic copper is safe (otherwise residential water pipes would be a terrible idea) but the salt form is not
The issue is that heat + something reactive can make salts. Copper sulfate from cooking onions for example. As a result copper pans are typically lined with a thin layer of a nonreactive metal like tin. This makes them both ridiculously expensive AND impractical because when the tin layer starts to wear away you have to get it re-tinned. This can be done at home but the bougie person with all copper cookware generally isn’t going to do that
Obviously cookware with “copper layers” embedded doesn’t have that drawback but this is marketing nonsense for the most part. “Better heat transfer” may be technically true but people have been cooking fantastic food on carbon steel pans for like 100 years and cast iron since the Han dynasty. If someone needs fancy cookware over a $30 pan it’s a skill issue
As you said cast iron does leech as well but it leeches dietary iron, which for most people is beneficial. Seasoning layer does not prevent this.
Metallic copper is safe (otherwise residential water pipes would be a terrible idea) but the salt form is not
The issue is that heat + something reactive can make salts. Copper sulfate from cooking onions for example. As a result copper pans are typically lined with a thin layer of a nonreactive metal like tin. This makes them both ridiculously expensive AND impractical because when the tin layer starts to wear away you have to get it re-tinned. This can be done at home but the bougie person with all copper cookware generally isn’t going to do that
Obviously cookware with “copper layers” embedded doesn’t have that drawback but this is marketing nonsense for the most part. “Better heat transfer” may be technically true but people have been cooking fantastic food on carbon steel pans for like 100 years and cast iron since the Han dynasty. If someone needs fancy cookware over a $30 pan it’s a skill issue
As you said cast iron does leech as well but it leeches dietary iron, which for most people is beneficial. Seasoning layer does not prevent this.