Most dishes, pots and pans can safely be cleaned in dishwashers. However, those not approved for dishwashers may suffer discoloration or stains. The intense heat the dishwasher uses to clean the dishes, combined with the caustic dishwasher detergent, can leave a grey residue on aluminum pans. Aluminum dishwasher cleaning isn't recommended because the surfaces of aluminum pans are simply too delicate to withstand the environment of a dishwasher.
An aluminum pan will tarnish in the dishwasher because of the combination of high heat inside the appliance and the corrosive properties of dishwasher detergents.
Aluminum Metal in Dishwasher
Anodized aluminum pans have a grey finish that is easily damaged in dishwashers. Pans made from cast aluminum are thicker and heavier but also have a delicate finish not suitable for dishwashers. As a general rule, you should not place any aluminum pans in dishwashers. Manufacturers note on packaging if pans are safe for dishwashers, so be sure to follow these recommendations to prevent damage to your cookware.
Discoloration may not affect the usefulness of the pan, but for some people, using beautiful cookware enhances the cooking experience.Tarnish will often occur on aluminum pans over time even if you do not wash them in the dishwasher, but they tarnish much faster when you do.
Gradual Grey Residue on Aluminum
When using the dishwasher for cleaning aluminum pans discoloration may not be noticeable at first, as it can take time for the surface to break down or for tarnish to form. That means you could wash the pan once in the dishwasher and decide that it is dishwasher safe. However, additional cleanings in the dishwasher may eventually tarnish the pan.
Heat and Detergent
Dishwashers can heat water to more than 140 degrees F. The heat is necessary to melt the detergent and remove grease and grime from the dirtiest dishes. The dishwasher detergent is often made up of harsh chemicals as well. When the chemicals combine with the hot water, they can leave a cloudy finish on aluminum pans that is hard to correct.
Proper Cleaning of Aluminum Pans
World of Pans recommends cleaning aluminum pans that are not safe for dishwashers in the kitchen sink using a mild dish detergent and warm water. This will help prevent cookware from tarnishing.
Avoid using abrasive pads or hard scrapers on the pans unless they are approved by the manufacturer for delicate pans, because they can scrape up the metal or scratch off non-stick coatings. Rinse thoroughly after cleaning. Acids like lemon juice can help get rid of tarnish on aluminum pans, too.
Removing Problem Stains
For burned-on food or grease, remove as much of the food as possible with a plastic spatula or sponge. Use a wooden spoon for food items that are really difficult to scrape off. After scraping, fill the pan with hot water and allow it to stand for about an hour. Finish the cleaning with warm soapy water and a sponge, then dry the pan to help prevent spotting and tarnishing over time.
Robert Lee has been an entrepreneur and writer with a background in starting small businesses since 1974. He has written for various websites and for several daily and community newspapers on a wide variety of topics, including business, the Internet economy and more. He studied English in college and earned a Bachelor of Arts in liberal arts from Governor's State University.