Sharp knives, wooden utensils, cast iron, copper cookware, crystal, fine china, and heirloom dishes should usually be washed by hand. Dishwashers can dull blades, crack wood, strip cast iron seasoning, tarnish copper, cloud crystal, and fade delicate patterns.
Other items need caution too. Nonstick pans, insulated mugs, plastics, and blender jars should only go in the dishwasher if the label says they are safe. Anything with stickers or adhesive labels should be cleaned separately because paper and glue can clog filters and leave residue.
The best habit is simple: check labels, hand-wash delicate or valuable items, clean your dishwasher filter regularly, avoid overloading, and use the right detergent. Taking a little extra care helps your kitchen tools last longer and keeps your dishwasher working properly.
