8 Things You Absolutely Should Not Put in a Dishwasher **(And Why)
The harsh detergents and high heat will completely strip away the polymerized oil layer—known as the seasoning—that gives cast iron its natural non-stick properties. Without this protective barrier, the iron will rust rapidly when exposed to moisture and air. Over time, repeated dishwasher cycles will severely degrade the iron’s surface.
How to care for them: Hand wash with hot water and a stiff brush (you rarely need soap). Dry the pan completely on the stove over low heat, and rub it lightly with oil after each wash to maintain the non-stick surface. Never soak cast iron for long periods.
4. Nonstick Cookware
It might seem counterintuitive since nonstick pans are designed to be easy to clean, but they should stay out of the dishwasher.
Knife block storage
Aggressive detergents and high temperatures break down the nonstick coating (like PTFE or Teflon), causing it to flake and lose its effectiveness. This accelerates wear and tear, meaning you’ll be forced to replace your expensive pans much sooner.
How to care for them: Hand wash with a soft sponge and mild dish soap. Avoid abrasive scrubbers like steel wool. Always let the pan cool completely before washing to prevent warping. While some newer ceramic-coated pans claim to be dishwasher safe, hand washing will always extend their life.
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.
Dishwasher detergent alternatives
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.
Kitchen cleaning supplies
