A dishwasher can make kitchen cleanup much easier, but some items can be damaged by high temperatures, strong detergents, powerful water jets, and long drying cycles. Before loading everything into the dishwasher, check whether the item is actually dishwasher-safe.

Here are 18 things you should generally wash by hand.

1. Wooden Cutting Boards

Wood can absorb water and swell during a dishwasher cycle. Repeated exposure to heat and moisture may cause a wooden cutting board to warp, crack, or split.

Better option: Wash it by hand with warm water and mild dish soap, then dry it thoroughly.

2. Wooden Utensils

Wooden spoons, spatulas, and other wooden tools can become cracked, warped, or rough after repeated dishwasher cycles.

Hand-washing helps preserve the wood and extend the life of your utensils.

3. Cast-Iron Cookware

Cast-iron skillets and pans should generally stay out of the dishwasher. Dishwasher detergent can remove the protective seasoning that gives cast iron its cooking surface.

Once the seasoning is damaged, the pan can become more susceptible to rusting.

4. Carbon-Steel Pans

Carbon-steel cookware also relies on seasoning for protection and performance. Dishwasher detergent and prolonged exposure to water can strip away that seasoning and encourage rust.

Wash carbon-steel pans by hand and dry them promptly.

5. Sharp Kitchen Knives

High-quality kitchen knives are better washed by hand. Dishwasher racks and other utensils can damage the sharp edge, while the detergent and heat may also affect the blade or handle.

There’s also a safety concern when unloading sharp knives from the dishwasher.

6. Nonstick Cookware

Some nonstick cookware is labeled dishwasher-safe, but repeated exposure to high heat and strong detergents can shorten the life of certain coatings.

Always check the manufacturer’s instructions. If you’re unsure, hand-washing is the safer choice.

7. Copper Cookware

Copper pots and pans can lose their shine and develop discoloration when exposed to dishwasher detergent and heat.

If you want to maintain their appearance, wash copper cookware by hand.

8. Fine Crystal Glassware

Delicate crystal glasses can be vulnerable to high temperatures, strong detergents, and contact with other dishes.

If the glasses are valuable or particularly delicate, hand-washing is usually the better option.

9. Hand-Painted Dishes

Hand-painted plates, cups, and bowls may have decorative finishes that can fade or wear away after repeated dishwasher cycles.

For dishes with detailed artwork or sentimental value, washing by hand can help preserve the design.

10. Vintage or Antique Dinnerware

Older dishes may have delicate glazes, painted decorations, or metallic details that aren’t suitable for modern dishwasher conditions.

When you’re unsure about an antique or vintage piece, hand-washing is the safer approach.

11. Gold- or Silver-Trimmed Dishes

Plates, cups, and glasses with gold or silver decoration can become dull or damaged by dishwasher detergents and heat.

Check the manufacturer’s care instructions before putting them in the dishwasher.

12. Insulated Travel Mugs

Some insulated travel mugs are dishwasher-safe, while others are not. High temperatures can potentially affect certain components or seals.

Check the manufacturer’s instructions, especially for vacuum-insulated mugs.

13. Vacuum-Insulated Bottles

Reusable insulated bottles often contain multiple components, including lids, seals, and gaskets.

Even when the main bottle is dishwasher-safe, some components may require hand-washing.

14. Certain Aluminum Cookware

Some aluminum pots, pans, and baking trays can become dull or discolored after exposure to dishwasher detergent.

Not every aluminum item is unsuitable for dishwashers, so check its care instructions first.

15. Non-Dishwasher-Safe Plastics

Thin or inexpensive plastic containers can warp or deform when exposed to the high temperatures inside a dishwasher.

Look for a dishwasher-safe label or symbol before putting plastic items on the rack.

16. Wooden-Handled Tools

Kitchen tools with wooden handles can absorb water and may eventually swell, crack, or loosen from the rest of the utensil.

Unless the manufacturer specifically says they’re dishwasher-safe, wash them by hand.

17. Items With Glued or Delicate Components

Some kitchen gadgets contain glued parts, decorative pieces, seals, or other components that may not tolerate high temperatures or prolonged exposure to water.

When you’re unsure, check the manufacturer’s care instructions before putting the item in the dishwasher.

18. Anything Marked “Hand Wash Only”

This is the easiest rule to remember.

If an item specifically says “Hand Wash Only,” don’t put it in the dishwasher. The manufacturer has determined that the item’s material, finish, coating, or construction may not tolerate dishwasher conditions.

What About Items Labeled “Dishwasher-Safe”?

A dishwasher-safe label generally means the manufacturer has designed and tested the item for dishwasher conditions. However, different parts of the same product may have different care requirements.

For example, a reusable bottle might be dishwasher-safe while its lid or rubber gasket needs to be washed by hand.

Always check the manufacturer’s instructions when you’re uncertain.

Final Thoughts

Dishwashers are excellent for everyday plates, glasses, and many kitchen utensils, but they’re not suitable for everything.

Wood, cast iron, carbon steel, delicate glass, copper, certain plastics, sharp knives, and specialty cookware often deserve extra care.

Taking a few minutes to wash these items by hand can help prevent warping, rust, discoloration, damaged coatings, and premature wear—and it may save you money on replacements in the long run.