The electro-chemical process that hardens aluminum is called hard anodization. Anodized cookware products are 30 percent harder than stainless steel, and therefore they are one of the most durable pieces of cookware you can purchase. Anodized products have a very long life span and will never peel, chip or corrode. They also resist abrasions, common in other types of cookware products. The anodization process also produces a non-porous smooth finish that helps prevent food and grease from sticking to the surface. Anodized cookwares are more commonly called hard-anodized cookwares.
Wash your hard anodized cookware in warm to hot soapy water. A rag, sponge or nylon scrub pad (such as a Scotch-Brite green pad) can be used to scrub away food and stains.
Rinse thoroughly in warm water and towel dry.
Clean stubborn stains with a baking soda and water paste. Use your nylon scrub pad to work it into the stain and let it sit for a half hour. Then wash, rinse and dry again. Some cookware manufactures state that you can clean baked-on grease and stubborn foods with a bleach product like Ajax, Soft Scrub or Comet. You would scrub it in with the nylon pad and then wash, rinse and dry.
Use a hard anodized cleaner to restore the luster of the hard anodized finish. For example, Calphalon makes a product called Dormond for this purpose.