Quality Cookware Base Contours

The most critical element in preventing pan warpage is the proper base contour. Aluminum expands when it heats up. If the base of an aluminum pan (or stainless steel pan with an aluminum disc) is absolutely flat prior to heating, it will most likely become convex when heated, due to metal expansion. This creates what is called a "spinner," making it unstable while cooking. Good Anolon cookware has a concave base so that when it heats up and the metal expands, the base remains flat and steady on the burner. Turn a pan over and put a ruler on the base. The center of the pan's surface should not touch the ruler but be slightly concave. Even pans with stamped impressions need this feature. A concave base, not the stamped impressions, is the essential deterrent to warpage.