🚫 8 Things You Absolutely Should Never Put in Your Dishwasher (And Why)

Modern dishwashers make life easier by saving time and effort, but not everything in your kitchen is designed to survive a hot wash cycle. While it may be tempting to load every dirty item into the machine, doing so can damage valuable cookware, shorten the life of your kitchen tools, or even harm your dishwasher itself.

Understanding what belongs in the dishwasher—and what doesn’t—can help you avoid costly mistakes and keep your kitchen items looking and performing their best.

Here are eight common items that experts recommend washing by hand.

1. Cast Iron Cookware

Cast iron skillets are famous for their durability, but they require special care. Most cast iron pans develop a protective layer called “seasoning,” which is created by baking oil onto the surface over time.

The high heat, powerful detergent, and long soaking cycle inside a dishwasher can strip away this seasoning, leaving the pan vulnerable to rust.

Instead, wash cast iron by hand using warm water and a soft brush, dry it immediately, and apply a thin layer of cooking oil before storing.

2. Sharp Kitchen Knives

Putting expensive kitchen knives in the dishwasher may seem convenient, but it can dull their blades surprisingly quickly.

Knives often knock against other dishes during the wash cycle, damaging both the blade and nearby items. Dishwasher detergents and prolonged exposure to moisture may also affect some knife handles.

To help preserve sharpness, wash knives by hand with mild soap, rinse thoroughly, and dry them immediately.

3. Wooden Utensils and Cutting Boards

Wood naturally absorbs water. Repeated exposure to high temperatures and moisture inside a dishwasher can cause wooden spoons, rolling pins, cutting boards, and serving bowls to warp, split, or crack.

Hand washing with warm, soapy water followed by thorough drying is the safest way to care for wooden kitchen tools.

Occasionally applying food-grade mineral oil can also help prevent drying and cracking.

4. Nonstick Cookware

Although many newer nonstick pans are labeled dishwasher-safe, repeated dishwasher use may shorten the lifespan of their nonstick coating.

Harsh detergents and high temperatures can gradually wear down the surface, making food stick more easily over time.

Hand washing is generally gentler and helps extend the life of these pans.

5. Fine China and Delicate Glassware

Family heirlooms, crystal glasses, and decorative china deserve extra care.

Strong water jets and high heat can cause delicate items to chip, crack, lose painted designs, or develop a cloudy appearance.

If an item has sentimental or financial value, washing it by hand is often the safest choice.