I have a copper bottomed steel top frying pan. I see many cookbooks saying that I should keep it very clean and shiny. I'm not sure I'm willing to put in the effort. My question is, if you're ok having a "patina" on your pan, do you really need to clean the copper part? I'd assume that it still conducts heat so is there some reason other than cosmetic why it would be important to keep very clean?
I've several instructions online about how to clean them, but feel free to add your advice on that front too.