Why Did My Aluminum Pan Tarnish in the Dishwasher?

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 tarnish aluminum pans. The surfaces of aluminum pans are simply too delicate to withstand the environment of a dishwasher.

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Some aluminum pans feature nonstick finishes not suitable for dishwashers.

Types of Aluminum

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. 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.

Advice

Manufacturers note on packaging if pans are safe for dishwashers. Always follow the recommendations. Damage to aluminum pans in dishwashers 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.

Environment

Dishwashers can heat water to more than 140 degrees. 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, it can leave a cloudy finish on aluminum pans that is hard to correct.

Proper Cleaning

Clean aluminum pans not safe for dishwashers in the kitchen sink using a mild dish detergent and warm water. 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.

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.