- Not everything is dishwasher-safe; some items can get ruined, while others are more apt to leach chemicals.
- Hand-wash wood, plastic, cast iron, aluminum, china, and anything nonstick, insulated or sharp.
- Washing by hand is much gentler than a dishwasher’s high heat and powerful jets.
While you may have heard crazy stories of people using their dishwashers to do everything from clean their shoes to cook a steak, the dishwasher isn’t made to do any more than what its namesake suggests. Unfortunately, not all dishes are created equal, so some of your dinnerware and kitchen tools should never wind up in your dishwasher.
We’ve rounded up a list of common kitchen items from sharp knives to fine china that are better off cleaned by hand—and some of them may surprise you. As a relatively new member of the “adult world,” I am guilty of dishwashing most of the things on this list and have learned the hard way about what does—and doesn’t—belong in your dishwasher.
1. Sharp Knives
Routinely tossing your nice knives in the dishwasher could actually be shortening their lifespan. One of our test kitchen staffers says she only hand-washes her knives because the dishwasher can be too abrasive. Additionally, rubbing against other cutlery in the utensil basket can cause even the sharpest knives to dull.
2. Wooden Utensils
I once washed a brand-new, beautiful set of wooden utensils in the dishwasher, only to find them looking warped and washed out afterward. The dishwasher’s high temperatures can be too much for wooden kitchen items, and you’re better off washing them yourself to keep their coating and shape intact.
3. Insulated Mugs
Insulated mugs can fall victim to some serious coffee stains if you forget about them for a few days (or more), and you’ll have to pay the price with a little hand-washing. Check the manufacturer’s care instructions to see if you can put your mugs in the dishwasher. However, even if they indicate they’re dishwasher safe, you may still want to consider handwashing them instead. The issue with dishwashers is that high temperatures and strong water jets can, over time, compromise the integrity of the products.
4. Certain Plastic Containers
The American Academy of Pediatrics advises hand-washing your plastic containers to limit the exposure your family receives from potentially harmful chemicals. This is because harmful chemicals can leach from them at high temperatures.
If you do have dishwasher-safe, BPA-free plastic containers, be sure to place them away from the heating element of your dishwasher. You may also want to avoid the “sanitize” cycle, since that’s when the dishwasher reaches its highest temperatures.
5. Cast-Iron Cookware
Our cast-iron pans are a little too precious to be tossed haphazardly into the dishwasher. What makes cast-iron cookware so great is the seasoning that builds up on it over time, and that can all be stripped away with some intense dishwasher sudsing.
6. Nonstick Cookware
Much of today’s nonstick cookware says “dishwasher safe” on the label, but that’s not necessarily true. According to one of our test kitchen pros, nonstick cookware will lose its special coating over time with some high-heat trips to the dishwasher, so you’re better off scrubbing by hand.
7. Graters and Colanders
Your grater or colander may not be damaged by the intense cleaning of your dishwasher, but the dishwasher won’t get off that Parmesan residue as well as a scrub brush will. Save yourself time and just clean it by hand.
8. Aluminum Baking Sheets and Pans
Aluminum won’t react well to your dishwasher’s high temperatures, which can cause discoloration. Sure, the pans are still usable, but they certainly aren’t as pretty. If you don’t want to take the time to hand-wash your baking pans, you may want to invest in some silicone options.
9. Fine China
A good deal of fine china is hand-wash-only, which is why your mom likely brought it out only on very special occasions. Appliance brand GE says any “antique, metal-trimmed, hand-painted china or over-the-glaze patterns are vulnerable to fading with high water temperature and detergent solutions, and therefore should not be washed in a dishwasher.” Turn your china-washing into a party with a loved one, blasting some music or catching up over suds.
Our Expert Take
A dishwasher is effective for many items, but not all. Some materials cannot withstand the high heat and powerful jet sprays of a dishwasher, which can ruin them or cause them to age prematurely. Always check the manufacturer’s care guidelines. Even if an item is labeled as dishwasher safe, consider hand-washing it instead, as this gentler method can help prolong its life. Think twice before putting anything wood, plastic, cast iron, aluminum, china, nonstick, insulated or sharp in the dishwasher.
