What not to put in dishwasher?

8 Items You Should Never Put in the Dishwasher

Hand washing these things will prevent any potential damage or warping under the high temperatures and strong water pressure of your dishwasher.

Madeline Buiano is the staff writer for MarthaStewart.com, sharing her knowledge on a range of topics—from gardening and cleaning to home and pets. She has five years of writing and editing experience in the digital publishing industry.

Published on March 6, 2023

Your dishwasher is a handy appliance that cleans dishes, cookware, utensils, and more kitchen items quickly and efficiently. While it would be convenient if you could wash everything in the dishwasher after using it to cook or eat, that’s simply not the case. Some items must be washed by hand to maintain the integrity of not just your appliance, but your kitchen tools.

Using the appliance to clean things that aren’t dishwasher safe can cause them to become damaged or warped during the wash cycle. While you should always check the manufacturer’s instructions before cleaning serveware and cookware, there are some pieces that should never be put in the dishwasher.

Fine China

Even if you only bring your fine china out once a year, you should still clean it by hand. «In general, it’s not recommended to put delicate or expensive china in the dishwasher due to the potential for damage from high water temperatures, strong water pressure, and abrasive detergents to cause color fading, delicate decorations, and hygiene concerns,» says Vera Peterson, president of Molly Maid, a Neighborly company.

Sharp Knives

While it’s typically fine to wash butter knives in the dishwasher, steak knives, bread knives, chef’s knives, and other sharp knives should be hand washed and dried with a soft towel. «Sharp knives should not go in the dishwasher as the items can be damaged and become warped while in the dishwasher,» says Lindsay Jones, new product brand manager at Maytag.

Cast Iron

Your cast iron pan has very specific care instructions and should never be cleaned in your dishwasher. «Cast iron cookware should not be put in the dishwasher as it can cause rust,» says Peterson. «Instead, clean it with a sponge or stiff brush and coarse salt, rinse, and dry completely.»

Non-Stick Pans

Do you want your non-stick pans to keep their coating? Then it’s best not to put them in the dishwasher. «It’s not recommended to put non-stick pans in the dishwasher as the high water temperatures, harsh detergents, and abrasive scrubbers can damage the non-stick coating,» says Peterson. «To extend the life of your non-stick pans, it’s best to hand wash them using a mild detergent and a soft sponge.»

Copper Cookware

Cookware made out of copper should also not go in the dishwasher; running them through a cycle may result in the items losing their coating when exposed to the hot water temperatures inside the machine.

Wooden Items

Cutting boards, spoons, salad bowls, and other kitchen items made from wood should be hand washed. «Wooden items should not go in the dishwasher as they can begin to become discolored [during the wash cycle],» says Jones.

Crystal

Generally, crystal serveware and drinkware is not dishwasher safe, so it’s best to err on the side of caution and wash these pieces by hand. «If you’re unsure about your glasses, it’s important to check the manufacturer’s instructions before putting them in the dishwasher,» says Peterson.

Aluminum Cookware

Some aluminum cookware, like pressed and cast, is not dishwasher safe, so it’s important to check the manufacturer’s instructions before washing these items. «Cookware items that are made out of anodized aluminum can go in the dishwasher, because these items are protected from chemicals that are used during the wash cycle,» says Jones.

On the other hand, pressed and cast aluminum can be damaged in the dishwasher. «Like cast iron, you should not put aluminum in the dishwasher as the detergent, high heat, and minerals in your water can trigger a reaction that darkens the metal,» says Peterson. Additionally, the jostling of items against each other can scratch the surface.

22 Things You Should Never Put In The Dishwasher

Part of the Southern Living team since 2017, Kaitlyn Yarborough is a Georgia native living in Austin, Texas, who covers a wide variety of topics for both the magazine and website, focusing on culture and lifestyle content, as well as travel in the South.

Updated on April 20, 2023
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A dishwasher can work some serious wonders in the kitchen and be a real timesaver. It’s a magical machine that replaces a precarious pile of dirty dishes with squeaky clean plates. Every holiday, tailgate, and bake sale season works overtime yet still delivers. You love the ease and convenience of using your dishwasher until that moment when you find your favorite coffee mug or keepsake plate broken.

It’s a devasting mistake, but it happens to every avid dishwasher user. There’s a way to avoid these mistakes, but it might require some elbow grease and a return to hand-washing dishes. Here’s a list of things you should never put in the dishwasher.

To Prevent Dull Edges

Chef’s Knives

A sharp chef’s knife can make or break your dinner prep, and putting it in the dishwasher dulls the blade over time. Instead of throwing your best tools into the machine, wash chef’s knives by hand to keep them in tip-top shape.

Food Graters

Like your best chef’s knife, you wouldn’t want the dishwasher to dull the blades in a food grater. This kitchen tool is best cleaned by hand.

To Prevent Fading

Copper Mugs & Cookware

Copper is a classic yet stylish pick for your cookware, and copper mugs are perfect for serving Moscow Mules year-round. After a big holiday party, throwing a copper mug into the dishwasher is tempting, but this drinkware will not sustain many cycles through the dishwasher. Make sure to hand-wash any copper items or other precious metals to keep their shine and luster intact and avoid discoloration or tarnishing.

Milk Glass

Whether you’re collecting vintage milk glass bowls from your great aunt or retro-inspired glassware from Anthropologie, be sure to hand-wash them unless you’re ready to risk discoloration. The semi-opaque milk glass will look yellow after a cycle through the dishwasher.

Drinkware, Measuring Cups, or Plates with Text

Over time, items with text can fade after many cycles in the dishwasher. A measuring cup isn’t helpful when the lines have disappeared.

Melamine Dishes

Melamine dishes and serve ware have withstood the test of time and proven popular even with the invention of new materials. Vintage melamine dishes and reproductions often have patterns or designs, so colors can crack or dull in a dishwasher.

Metallic Gold Flatware

Unlike its silver counterparts, the sheen on gold flatware fades over time when using a dishwasher. This fading also goes for plates with a gold-metallic design, so to be safe, always hand-wash these items.

Hand-Painted Items

Your favorite hand-painted decorated piece won’t look the same once it starts to fade. To protect decorative or delicate plates, mugs, or any other painted items, hand-wash and gently scrub with a smooth sponge, so you don’t peel off any paint.

Paper Items

These will fade in the dishwasher if a mug has any decorative paper elements. Similar to text and other decorative embellishments, paper is too delicate to withstand the heat and hot air in a dishwasher.

To Prevent Structural Damage

Insulated Mugs & Cups

Your favorite and most trusted travel mug might not be airtight after a couple of visits to the dishwasher. The same goes for plastic or metal insulated cups. The insulated airspace that keeps your hot or cold liquids gets compromised and loses efficiency. If you’re desperate because you finally found a lost insulated tumbler under your car seat after a long, hot summer month, opt for the top rack and skip the high heat of the drying cycle.

Wooden Utensils & Cutting Boards

The dishwasher’s hot water and dry heat can warp or crack wooden kitchen utensils and cutting boards, rendering them less-than-useful. The heat dries natural wood cutting boards, making them look sad and faded.

Pressure Cooker Lids

This one is a big no-no. While your pressure cooker pot might be acceptable, the lid poses a safety issue. The dishwasher cycle can warp or damage the rubber seal on the cover, as well as damage the valves and vents that the lid uses when cooking. These things can lead to many problems, including pressure cooker explosions.

Nonstick Skillets & Sheet Pans

Some nonstick cookware reportedly is «dishwasher safe.» We don’t distrust that fact, but we also know that the dishwasher can degrade the nonstick coating on your nonstick skillets and sheet pans, rendering them less effective. Read your labels, and proceed with caution.

To Protect Materials

Aluminum Cookware

The dishwater’s scalding water can stain or dull aluminum cookware. Stainless steel has a better chance in the machine, but you should always check the labels after purchasing. In our experience, better safe than sorry!

Cast-Iron Skillets

Your cast-iron skillet is such a game-changer for gooey cobblers and classic cornbread that it’d be a real shame to lose it. The seasoning on a cast-iron skillet makes it unique, and the dishwasher can degrade the coating and eventually lead to rust.

Fine China

This rule should be a given, but we’d never get past the guilt if we didn’t at least give fair warning. Before you line up your heirloom dishes in the dishwasher, think again. It can cause them to chip, fade, or lose their finish. This practice is essential if the patterns have metallic detail.

Crystal

Crystal stemware and dishes can crack, chip, or break due to the high heat of a dishwasher. These pieces can also be stripped of their sheen or become etched or cloudy after repeated washings. Check the manufacturer’s directions before loading because some types cannot be washed even on a dishwasher’s delicate cycle, or play it safe and hand-wash.

Pewter

As previously mentioned, with metallic gold items, a pewter serving dish will not withstand many cycles through the dishwasher. As many pewter items are vintage or antique, this is especially true because of the delicate construction.

Plastic

Unless specifically designated as «dishwasher safe,» placing a plastic container in a dishwasher runs the risk of melting at extreme water and air temperatures. Even if technically «dishwasher safe,» a plastic container continuously placed in a dishwasher risks losing its sturdiness over time which can be dangerous if pieces of the plastic end up in your food.

To Protect the Dishwasher

Plates with Food On It

This decision is a highly debated topic regarding dishwashers, but placing dishes with large pieces of food on them will not do your machine any good in the long run. Leaving food on a plate can clog your dishwasher, making it susceptible to breaking in the future.

Broken Dishes

If a plate or mug already has a chip in it, that dish is more likely to continue cracking when put through the dishwasher cycle’s hot water and dry heat. Not only is this not a good practice for your dishwasher, but it can also potentially be harmful as pieces can fall apart during your subsequent use.

Containers with Adhesive Labels

The first stop is always the sink or dishwasher to save glass jars and containers for reusable storage. However, it’s crucial to remove the paper label beforehand. If a piece dislodges during the cycle, it can clog the dishwasher drain and food disposal system and lead to damage with a hefty price tag.

So always remember, your dishwasher works some magic, but not miracles. Keep this list handy, and don’t ruin your favorite kitchen tools.

What, are you crazy? Don’t put that in your dishwasher!

You can’t just throw everything into the dishwasher all willy-nilly.

Credit: Flickr user «m01229»

Written by Tyler Wells Lynch

Updated June 28, 2016

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As wonderfully convenient as dishwashers are, they are not all-purpose miracles of technology that you can entrust with cleaning anything you can get your mitts on. It’s surprising how many people have to learn this the hard way. While some things may survive a run or two, certain items should never be put through a dishwasher cycle. Here’s a rundown of what not to do.

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Never put these in your dishwasher

Cast Iron: The inside of an active dishwasher is hot and wet—two conditions that are disastrous for certain kinds of cookware. Not only will dishwasher cleaning cause cast iron skillets to rust, it will also wash away the seasoning—that protective, nonstick, and delicious layer of oil and lard. Unless you want your cast iron cookware to end up looking like some sort of prehistoric anvil, don’t put it in your dishwasher.

Wood: Once again, dishwashers get hot—really hot. Heat causes wood to warp, so avoid putting wooden objects in your dishwasher. That includes utensils, bowls, cutting boards, and even pots and pans with wooden handles. Furthermore, the dry cycle may cause the wood to crack, opening up a breeding ground for bacteria.

Wood will warp and split under the heat and pressure of a dishwasher.

China and Delicate Glassware: This one should be obvious: Don’t put delicate wine glasses, china, or other formal wares in your dishwasher. What are you thinking? The chemicals in dishwasher detergents are abrasive, so they’ll wear away at delicate materials and cause them to crack. The intense heat of a dishwasher can also cause glasses and china to shatter, which is sure to put you at odds with whoever owns those precious family heirlooms you were too lazy to wash by hand. Not to mention, you’ll have to manually clean shattered glass out of the wash tub, which sounds like a blast but is probably hazardous, to say the least.

Gold-Trim Dishes: What, are you stupid? They’re almost always delicate (see above), and even if they don’t wreck the entire plate, the water jets can spray away flakes or chunks of gold.

Insulated Travel Mugs: Travel mugs have a vacuum seal between the inner and outer shell, which can be breached when it’s put through the dishwasher. Aside from filling the vacuum with water for an annoying sloshing sound, it can hinder the mug’s ability to retain heat, thereby defeating the whole purpose of a travel mug.

You probably shouldn’t put these in your dishwasher

Teflon: There’s a lot of debate over this one, but we’ll go ahead and say you probably don’t want to put Teflon in your dishwasher. Recent research has suggested that polytetrafluoroethylene—the chemical name for Teflon—is carcinogenic, particularly when it begins to break down. That reason alone should be enough to scare you away from the idea of agitating it in a high-temperature alkaline box. Manufacturers like Dupont say it’s fine, and dishwashing it a few times over several years is probably okay. But frequent washing is likely to hasten the breakdown process, coating other dishes and utensils with undesirable chemicals. And honestly, how easy is it to wash nonstick pans by hand anyway? Don’t be lazy.

Stainless Steel: Most experts say it’s okay to put stainless steel products in the dishwasher—but with a few caveats. The general fear is that detergent and excessive humidity will corrode the metal, and that acidic food soils will tarnish its polish. It’s also recommended that, if you do choose to put stainless steel in the dishwasher, it should be placed in the upper rack or the cutlery basket and spaced far enough away from other materials so as to ensure proper washing and drying. However, we feel there are far too many precautions, and that you’re better off just washing stainless steel by hand.

Stainless still might survive a dishwasher cycle, but be smart, and just wash your pots and pans by hand.

Aluminum: Some aluminum products are specifically designated to be “dishwasher-safe.” These materials are probably fine, but others may be prone to scratching. They may also develop a dull finish over time. We’d recommend taking this category on a case-by-case basis.

Knives: Knives turn into sporks when put through the dishwasher. OK, not really, but they do dull over time in the dishwasher. Then you have little more than a blunt object for cutting vegetables, and you’re no troglodyte, so wash your precious blades by hand. Just be careful.

Plastic: If a plastic item is not clearly guaranteed “dishwasher-safe” by the manufacturer, then wash it by hand. The heat from the water and dry cycle can warp the material and possibly even melt it. Even if the item is deeded safe for the dishwasher it’s a good idea to place it in the upper rack—or as far away from the heating element as possible. But anyone who’s ever had to deal with melted plastic in their dishwasher might recommend staying on the safe side and avoiding it altogether.