Discover 18 things you should never put in the dishwasher, from wooden utensils and cast iron to delicate glassware and sharp knives, and learn safer ways to clean them.
18 Things You Should Never Put in the Dishwasher (Even If You’re Tempted)
The dishwasher can save you time and effort, but not everything in your kitchen belongs inside it. High temperatures, powerful water jets, strong detergents, and prolonged moisture can damage certain materials, dull finishes, or even shorten the life of your favorite kitchen tools.
Before you toss everything into the next cycle, check this list of 18 items that are generally better washed by hand.
1. Cast-Iron Cookware
Cast-iron pans should generally be kept out of the dishwasher. The combination of water and detergent can strip away the seasoning and encourage rust.
Instead, clean cast iron by hand with a small amount of mild soap or the method recommended for your particular pan, then dry it thoroughly.
2. Wooden Utensils
Wooden spoons, cutting boards, and other wooden kitchen tools can crack, warp, or become rough after repeated exposure to hot water and drying cycles.
Hand-washing and promptly drying them can help preserve the wood.
3. Sharp Kitchen Knives
The dishwasher can cause knife blades to become dull more quickly. Knives can also move around during a cycle, potentially damaging other items or creating a safety hazard when unloading.
Hand-wash sharp knives carefully and dry them immediately.
4. Nonstick Cookware
Some nonstick pans are labeled dishwasher-safe, but repeated dishwasher cycles can gradually wear down certain coatings.
When in doubt, check the manufacturer’s instructions. Hand-washing with a soft sponge is often the gentler option.
5. Copper Cookware
Copper can lose its shine or develop discoloration when exposed to dishwasher detergents and heat.
If you want to preserve the appearance of copper cookware, hand-washing is usually preferable.
6. Crystal Glassware
Delicate crystal glasses can be vulnerable to chips, scratches, and cloudiness in a dishwasher.
Wash valuable or particularly delicate crystal by hand using a gentle detergent.
7. Hand-Painted Dishes
Decorative or hand-painted plates and cups may have finishes that aren’t designed to withstand repeated dishwasher cycles.
Hand-washing can help preserve their colors and artwork.
8. Antique Dishes
Older dishes may have fragile finishes, decorative details, or materials that weren’t designed for modern dishwasher conditions.
If an item is valuable or sentimental, hand-washing is the safer choice.
9. Insulated Travel Mugs
Some insulated mugs and bottles have seals, vacuum insulation, or special finishes that can be damaged by high temperatures.
Always check the manufacturer’s instructions before putting them in the dishwasher.
10. Wooden-Handled Tools
Kitchen tools with wooden handles can absorb water and eventually swell, crack, or loosen from the rest of the utensil.
A quick hand wash is generally much kinder to these items.
11. Aluminum Cookware
Certain aluminum cookware can become discolored or develop a dull appearance after exposure to dishwasher detergent.
Check the manufacturer’s care instructions before washing aluminum items in the machine.
12. Items With Non-Dishwasher-Safe Labels
This may sound obvious, but always pay attention to the manufacturer’s instructions.
If an item specifically says “hand wash only,” don’t assume that one dishwasher cycle won’t matter. Repeated exposure can cause gradual damage.
13. Fine Graters
Sharp graters can potentially damage other items or be difficult to clean safely in a crowded dishwasher. Hand-washing also gives you better control when removing food trapped between the sharp surfaces.
14. Wooden Cutting Boards
Even if a wooden cutting board looks sturdy, repeated dishwasher cycles can cause warping, cracking, or splitting.
Wash it by hand and allow it to dry completely.
15. Delicate Glasses
Thin wine glasses, vintage glassware, and unusually delicate drinking glasses can break or chip when they come into contact with other dishes or during the strong dishwasher cycle.
16. Non-Dishwasher-Safe Plastics
Some plastic containers can warp, melt, or release unpleasant odors when exposed to high heat.
Look for a dishwasher-safe symbol or check the manufacturer’s instructions before loading plastic containers.
17. Certain Pressure Cooker Components
The main pressure cooker pot may be dishwasher-safe depending on the model, but some lids, sealing rings, valves, and electrical components should not go into the dishwasher.
Always follow the specific manufacturer’s cleaning instructions.
18. Anything With Loose or Fragile Parts
Items containing delicate seals, glued components, decorative attachments, or small removable pieces can be damaged or separated during a dishwasher cycle.
When you’re unsure, hand-washing is often the safer option.
A Simple Rule to Remember
When deciding whether something belongs in the dishwasher, consider the material, finish, construction, and manufacturer’s instructions.
High heat and strong detergent are excellent for many everyday dishes, but they’re not ideal for everything. If an item is expensive, delicate, antique, wooden, cast iron, or sentimental, hand-washing is usually worth the extra few minutes.
Final Thoughts
Your dishwasher is incredibly convenient, but using it for everything can lead to cracked wood, damaged coatings, dull knives, cloudy glassware, and ruined finishes.