When it comes to making Chicago style deep-dish pizza one must consider several things when selecting a pan. Steel pans work well, but they must be seasoned to give good release properties as well as improved baking properties. While this next one won't impact you at home, it will have an impact on a store's pan selection. If the pizza is sent out to the table in the pan it is baked in, the food safety laws will dictate that the pan be washed before it can be reused. Steel pans are prone to rusting, but the biggest problem is with the seasoning, if the pans are soaked in hot soapy water for any significant length of time, the seasoning will begin to peel off like a bad sunburn, the consequences of which are to raise the concern of the health department as they ponder where the material went, did it go with the pizza? Did the customer eat it? Not good. Hardcoat, anodized aluminum pans (good ones are made from heavy weight aluminum stock). The dark color of these pans will not lift off even if soaked for an extended time in hot soapy water. The finish on some manufacturers pans is very durable (can't be scratched or abraded with the edge of a coin), but just like a seasoned steel pan, the anodized coating can be damaged by cutting the pizza in the pan. This is why we commonly see the pizza removed from the pan for cutting and then placed back into the pan for serving. Pizza Hut used to do this at one time with their deep-dish pizzas, maybe they still do, but can't tell you the last time I was at a P.H., but the time would be measured in years. The better pans/coatings are also resistant to scratching when the pizza is dug/guided out of the pan using a cake decorating spatula.
Tom Lehmann/The Dough Doctor