5. Anything with Adhesive Labels
We’ve all tried to scrub a baked-on sticker off a dish after a dishwasher cycle—it’s a nightmare.
When exposed to high heat and water, labels disintegrate, leaving a stubborn, sticky residue on your dishes and inside the machine. Worse, the paper fragments and melted glue can clog your dishwasher’s filter, drastically reducing its cleaning efficiency. You’ll end up spending more time scraping off residue than you saved by using the machine.
How to care for them: Always remove all labels and stickers before loading. Soak stubborn labels in warm, soapy water to loosen the adhesive, and gently use a razor blade or scraper to remove any leftover glue.
6. Insulated Travel Mugs and Thermoses
Insulated mugs are fantastic for keeping beverages at the perfect temperature, but the dishwasher can ruin their internal mechanics.
The intense heat can damage the vacuum seal between the double walls, compromising the mug’s ability to retain temperature. Additionally, plastic lids and rubber seals can warp or degrade, leading to leaks, and harsh detergents can leave a lingering chemical taste or odor inside the container.
How to care for them: Hand wash the body and lid with warm, soapy water, using a bottle brush to reach deep inside. Air dry completely with the lid off to prevent mold and mildew. Always check the manufacturer’s instructions, but hand washing is universally the safest bet.
7. Copper Cookware
Copper pots and pans are stunning kitchen treasures, but they are incredibly finicky.
Harsh detergents and high heat will quickly tarnish the beautiful finish, turning it dark and spotty. The dishwasher cannot provide the specific care required to maintain that polished shine, and some detergents can actually react chemically with the copper, causing pitting or corrosion.
How to care for them: Hand wash with mild soap and warm water, and dry immediately to prevent water spots. Polish regularly with a copper-specific cleaner or a simple homemade paste of lemon juice and salt.
8. Old or Valuable China
If you have heirloom china or dishes with delicate, hand-painted patterns, keep them far away from the dishwasher.