16 Kitchen Items You Should Never Put In The Dishwasher

As tempting as it is to toss everything into the dishwasher and hit start, some kitchen items just don’t belong there — no matter how tired you are. Yeah, it’s convenient, but trust me, you’ll regret it when your favorite pan comes out dull or your knives lose their sharp edge. Some things just need that good old handwashing love and a bit of elbow grease.

You might be surprised how many of these items you’ve probably been washing the wrong way your whole life. A few of them you already know should never go in the dishwasher, but maybe you’ve ignored the rule once or twice (we’ve all been there). And others — well, you might not even know why they shouldn’t go in there.

But here’s the deal — avoiding the dishwasher for certain items can actually save you money, extend the life of your kitchenware, and even help keep your dishwasher running longer. Plus, some of these mistakes can affect your food safety, and that’s definitely not something to mess around with.

So before you hit that start button again, check out this list of 17 kitchen items that should never go in the dishwasher. From nonstick pans and cast iron skillets to sharp kitchen knives, crystal glasses, and even wooden cutting boards, these are the things that need a little extra care.

A few extra minutes of handwashing can save you from replacing expensive items later — and let’s be real, those high-end cookware sets, premium glassware, and chef’s knives aren’t cheap. So skip the dishwasher for these, grab some warm water and soap, and keep your kitchen gear in top shape for years to come.

1. Cast iron cookware, including enameled cookware

One of the biggest mistakes people make with cast iron cookware is tossing it into the dishwasher. Big no-no. Whether it’s your classic cast iron skillet or that fancy enameled cast iron pot (like your beloved Le Creuset), the dishwasher is basically their worst enemy. These pans are meant to last a lifetime — seriously, they can even become family heirlooms — but one bad wash can ruin them for good.

Here’s why you should always handwash your cast iron. For your regular, non-coated skillets, the dishwasher’s harsh detergents strip away that beautiful layer of seasoning — the natural oil barrier that makes your pan non-stick. Once that’s gone, food sticks, flavor fades, and rust starts creeping in. And all that steamy, standing water inside your dishwasher? It’s a rust magnet.

Now, for your enameled cast iron cookware, like that gorgeous Dutch oven, the risk is just as real. The dishwasher’s high heat, strong jets, and detergent can chip or dull the enamel finish. Even if the manufacturer says it’s “dishwasher safe,” it’s not worth gambling on. Every wash weakens the coating a little more — and we all know how pricey those Le Creuset pots are.

The best way to clean cast iron? Keep it simple: warm water, a soft sponge, and maybe a pinch of coarse salt if something’s stuck. Dry it right away and rub a bit of oil to keep it protected. That’s it. Your pan will thank you, and you’ll get decades of perfectly seared steaks and crispy cornbread in return.

2. Nonstick pans

Non-stick pans might say they’re dishwasher safe — but don’t fall for that. If you want your non-stick cookware to actually last, skip the dishwasher and go old-school with handwashing. Sure, tossing it in with the rest of your dishes sounds easy, but it’s a fast track to ruining that smooth, slippery coating you paid for. And honestly, pan manufacturers don’t mind if you wreck it early — it just means you’ll be buying a new one sooner.

Here’s the deal — dishwashers are brutal on non-stick surfaces. The high-pressure water jets, the strong detergent, and even how tightly you pack your dishes can all mess things up. The powerful spray can start peeling or bubbling the coating, and the harsh soap enzymes can eat away at it over time. Plus, if another plate or pan bumps against it during the cycle, say goodbye to that flawless finish.

Once the coating starts to flake or peel, it’s game over. You’ll notice little bits of it mixing into your food — and yeah, nobody wants a side of Teflon flakes with their eggs.

To make your non-stick pans last longer, just handwash them with warm water, a soft sponge, and mild soap. Avoid scouring pads or metal utensils, and never soak them for too long. Dry them well before storing to keep the surface in good shape.

3. Wooden utensils, cutting boards, and kitchenware

It’s super tempting to toss your wooden kitchen tools into the dishwasher and call it a day — but don’t do it. Seriously, if you want your wooden stuff to last, handwashing is the only way to go. This rule covers everything from wooden cutting boards and utensils (like spoons, salad tongs, and chopsticks) to wood-handled spatulas and bowls. Basically, if it’s wood, keep it far away from that dishwasher.

Here’s why: the dishwasher is like a sauna mixed with a hurricane — super hot, super wet, and super bad for wood. The heat and moisture cause the wood to swell, warp, and eventually crack. You might get away with it once or twice, but sooner or later, your beautiful wooden cutting board will start looking more like a potato chip than a flat board.

And it’s not just about warping. Those glued joints that hold your cutting boards or utensils together? The constant soaking and drying cycle weakens the glue, making them split or fall apart. Once that happens, it’s nearly impossible to fix. Plus, dry wood can become rough and splintery — the last thing you want when you’re mixing a salad or stirring soup.

To keep your wooden kitchen tools in great shape, wash them gently by hand with warm water and a bit of mild soap. Wipe them dry right after — don’t let them air-dry in a puddle of water. Every few weeks, rub in a little food-safe mineral oil or wood conditioner to keep them from drying out. It’s a small effort that makes a big difference.

4. Copper cookware and other copper items

Copper cookware might look stunning in your kitchen, but tossing it into the dishwasher is a total disaster waiting to happen. Honestly, most metal cookware doesn’t belong in there — but copper, in particular, needs some serious TLC. Its delicate, easily-tarnished surface can’t handle the intense heat, harsh detergents, and banging around that happens inside a dishwasher.

When you put your copper pots and pans through a wash cycle, you’re basically asking for trouble. The combination of heat and detergent strips away the shine, leaving your once-gorgeous copper looking dull, discolored, or even green. That green tint? That’s oxidation — and it’s not the kind of “patina” you want in your kitchen.

Beyond looks, it’s also about safety and longevity. Those scratches from clanging against other dishes can expose the raw copper underneath. Once that happens, the metal can start to leach into your food, especially if you’re cooking something acidic like tomato sauce or vinegar-based dishes. Over time, that can lead to copper toxicity, which definitely isn’t something you want to mess around with.

So yeah, even if it’s tempting, always handwash your copper cookware. Use warm water, a gentle sponge, and mild soap. For tarnish, mix a little lemon juice with salt or use a copper cleaner to bring back that golden glow. After cleaning, dry everything immediately with a soft towel to prevent water spots or corrosion.

5. Delicate glassware and crystal

If you’ve got fine glassware or crystal, keep them far, far away from the dishwasher. I know it’s tempting to just pop those fancy wine glasses in for a quick clean, but if you want them to stay clear, sparkly, and chip-free, handwashing is the way to go. Sure, your sturdy everyday glasses might survive a dishwasher cycle if you load them carefully — but those delicate crystal pieces? Not so much.

Here’s the thing — dishwashers are way too rough on fragile glass. The high heat, powerful jets, and constant clinking of glass against other dishes can easily cause cracks, chips, or full-on breakage. Crystal, in particular, is super fragile and porous. That means it can absorb odors (yes, even from dish soap!) and lose its beautiful clarity over time.

And if your glassware has any painted designs or gold rims, the dishwasher will slowly strip those away, leaving them dull and patchy. Even worse, the minerals in hard water can build up on the surface, creating that cloudy film that’s almost impossible to get rid of. Once etched, that glass won’t ever look crystal-clear again.

Another serious reason to handwash? Vintage crystal with lead glaze. Washing it in the dishwasher can cause lead to leach out, contaminating not just the glass, but other dishes — and even your dishwasher itself. Yeah, not worth the risk.

6. Pressure cooker lids

Here’s the thing about pressure cookers — while the non-stick metal pot itself can usually handle the dishwasher, the lid absolutely can’t. Yep, whether it’s an electric pressure cooker lid (like an Instant Pot) or a stovetop pressure cooker lid, it needs some gentle handwashing love.

The reason? Those lids are full of little parts that just don’t play well with dishwashers. Inside, you’ve got valves, vents, and seals — all crucial for maintaining pressure and keeping your food safe. During a dishwasher cycle, food particles and soapy residue from other dishes can get stuck in those tiny passageways. Since the machine’s water jets aren’t strong enough or targeted enough to clear them, you can end up with clogged vents — which is not only gross but can also mess with how your pressure cooker functions next time.

Then there’s the rubber gasket — the flexible ring that helps create that airtight seal. Even if it’s made from silicone (and technically “dishwasher safe”), the constant high heat and steam can cause it to dry out, crack, or lose elasticity. Over time, that means your pressure cooker won’t seal properly, and you’ll be replacing gaskets way more often than you should.

So yeah, just handwash the lid. Use warm water, mild soap, and a small brush or toothpick to gently clean around the valves and seals. Make sure everything is completely dry before putting it back together — moisture trapped in those areas can cause mold or weird smells.

7. Sharp knives

If you’ve been tossing your sharp kitchen knives into the dishwasher, it’s time for a reality check — and a new cleaning habit. Putting knives in the dishwasher isn’t just bad for the blades, it’s also bad for your dishwasher itself.

Think about it — those sharp edges aren’t just for slicing veggies. When they rattle around inside the wash rack, they can easily cut through the plastic coating on your dishwasher’s racks or utensil baskets. Once that coating is damaged, the metal underneath starts to rust, and before you know it, you’re looking at a pricey rack replacement. Not exactly worth the few seconds you saved by skipping handwashing, right?

Then there’s the heat. The intense temperatures from the dishwasher’s washing and drying cycles can cause knife handles, especially wooden ones, to warp, crack, or splinter. The constant banging against other dishes doesn’t help either — it dulls the blade, chips the edge, and can even nick your other cookware or glassware. Basically, it’s a lose-lose situation.

The fix is super simple: handwash your knives. Just a little warm water, mild soap, and a soft sponge will keep them sharp and shining. Dry them right away to prevent rust or water spots, and store them safely in a knife block or magnetic strip.

8. Thin plastic, acrylic, or melamine

Not all plastic is created equal — and that matters big time when it comes to your dishwasher. While hard plastic containers are often labeled as dishwasher safe, thinner plastics, acrylic, and melamine definitely are not. Even with the “safe” ones, it’s usually smarter to just wash them by hand with warm soapy water if you want them to last longer.

Here’s the deal — reusable plastic containers are typically designed to handle gentle washing, but disposable plastics? Not so much. Those takeout containers and cheap meal prep boxes might look sturdy, but one hot dishwasher cycle can warp them, melt them, or even release chemicals you don’t want near your food.

Then there’s soft or flexible plastic — that stuff can’t handle the heat or harsh detergents at all. It’ll lose its shape, warp, or come out half-melted and useless. Acrylic and melamine are also big no-nos for the dishwasher. Over time, they’ll fade, crack, or even break, especially when exposed to high heat or long cycles.

And even for plastics that are dishwasher-safe, you still need to be careful. Always place them on the top rack, away from the heating element. Use gentle cycles — avoid “sanitize” or “deep clean” settings, which get super hot and can easily damage or warp the plastic.

9. Air fryer baskets

One of the best things about an air fryer is how easy it is to clean — but here’s the catch: you really shouldn’t be tossing your air fryer basket in the dishwasher. Yeah, we know, the manual might say it’s “dishwasher safe,” but there are a few solid reasons to rethink that move if you want your air fryer to last (and stay safe to cook with).

The biggest issue? That non-stick coating. Just like with non-stick pans, the high heat, harsh detergents, and rough water jets in a dishwasher can cause the coating to flake, peel, or bubble over time. Once that happens, those flakes can end up in your food — and no one wants a side of Teflon with their fries. Even worse, when that damaged coating heats up, it can release toxic fumes and chemicals, especially at high cooking temperatures.

Even if you only use liners or metal racks in your air fryer, a basket with a compromised coating can still be a problem. It’s just not worth the risk. The best move? Handwash your air fryer basket using warm water, mild dish soap, and a soft sponge or brush. Avoid anything abrasive that might scratch the surface.

If you’re tired of worrying about non-stick coatings altogether, consider upgrading to an air fryer with a glass basket or one that uses ceramic or silicone coatings. They’re safer, easier to clean, and won’t flake off into your food.

10. Silver and sterling silver cutlery and kitchenware

We get it — cleaning silver cutlery and silver kitchenware by hand can be a total chore. After scrubbing and polishing, the idea of tossing it all in the dishwasher sounds pretty tempting. But here’s the truth: even though some silver items are labeled “dishwasher safe,” it’s rarely worth the risk. Unless you follow some very strict washing rules, you could end up dulling, tarnishing, or even ruining your silver for good.

Here’s what you need to know — pure silver and sterling silver should never go in the dishwasher. These pieces react badly to the strong detergents and high heat, not to mention the chemical mix happening when they’re washed alongside other metals. The result? Tarnish, black spots, discoloration, and even permanent surface damage.

Now, silver-plated items might seem a little more durable, but they’re still tricky. The detergent you use makes a big difference. If it contains citric acid (which many do), it’ll corrode the silver layer over time. Also, mixing silverware with stainless steel in the same wash load is a big no-no — it causes a chemical reaction that leaves your silver looking oxidized and patchy.

So yeah, while the dishwasher might seem like a shortcut, it’s better to handwash your silverware the old-fashioned way. Use warm water, mild soap, and a soft cloth or sponge. Rinse and dry immediately to prevent water spots and tarnish. And if you really want that sparkle, give them a quick polish with a silver-safe cleaner once in a while.

11. Aluminum cookware and kitchenware

Just like copper and pure silver, aluminum cookware and kitchenware have no business being in the dishwasher. Before you hit that start button, double-check what your pans, baking sheets, and pots are made of — because aluminum and dishwashers definitely don’t mix well.

Here’s why: aluminum reacts badly to the harsh detergents used in dishwashers. The first time, it might just come out looking a little dull — no big deal, right? But after a few more cycles, things get ugly fast. Your shiny pans will start turning dark, patchy, and even corrode or pit over time. Some aluminum items even develop that weird grey powdery coating, which is a sign of oxidation and detergent damage. So, if your once-smooth baking sheets are now looking rough and spotty, the dishwasher is probably the culprit.

Even hard-anodized aluminum cookware, which is a bit tougher, can only handle so much. Each wash cycle slowly wears down the protective layer, shortening its lifespan and ruining its finish. And sure, some brands claim their aluminum pots are “dishwasher safe,” but the truth is — every cycle takes years off their life.

While there are special aluminum-safe dishwasher detergents, they’re not exactly easy to find, and most of them are industrial-grade — meaning they’re way too caustic for home use. So really, it’s just not worth the risk.

The best way to clean aluminum cookware? Keep it simple — handwash with warm water, mild soap, and a soft sponge. Skip the steel wool or harsh scrubbers, and dry everything right away to prevent water spots or oxidation.

12. Fine china and certain types of earthenware

While most everyday china and ceramic dishes are labeled “dishwasher safe,” that doesn’t mean all dishware should go in there. Some pieces — especially fine china, vintage ceramics, and handmade pottery — need a little extra care. The truth is, even the gentlest dishwasher cycle can be too harsh for delicate, older, or decorative pieces.

Here’s the deal — if your dishware is antique, hand-painted, or has metallic trim, it’s best to stick with handwashing. The intense heat, water pressure, and strong detergents in modern dishwashers can easily damage these finishes. Over time, gold or silver trim can tarnish or wear away, and painted patterns can fade until they’re barely visible.

Even older china or ceramics that are 15–20 years old might struggle to survive a dishwasher cycle — and that totally qualifies as “antique” in dishware years. The glazes used back then weren’t made to withstand today’s powerful detergents, and once they start to break down, your once-beautiful dishes can look dull, cracked, or even crazed (those tiny spiderweb-like cracks in the glaze).

The same goes for earthenware or crockery. These types of pottery are more porous than modern ceramic, meaning they can absorb water and detergent residue, leading to cracks or discoloration. And if you already see hairline cracks or glaze crazing, putting them in the dishwasher will only make things worse.

So yeah, handwashing might take a few extra minutes, but it’s 100% worth it. Use warm water, a soft sponge, and a mild detergent — no scouring pads or harsh soaps. Then dry each piece gently with a soft towel to prevent water spots.

13. Graters

Okay, we know this one might make you roll your eyes — but cheese graters and zesters really don’t belong in the dishwasher. Yeah, cleaning them by hand can be a bit of a pain (especially when there’s dried-on cheese stuck in every little hole), but trust us — it’s worth the effort.

Here’s the thing — graters are designed with tons of tiny, razor-sharp edges that slice through food like butter. The problem is, those same sharp edges can also slice into the plastic coating of your dishwasher racks. Once that coating’s gone, the exposed metal underneath will start to rust, and then you’re looking at an expensive repair or replacement.

Even if your dishwasher doesn’t get damaged, the grater itself can suffer. The high heat and harsh detergent dull the blades over time, making them less effective. And depending on your dishwasher’s water pressure, it might not even get your grater clean. Many people find that food bits — like cheese, garlic, or lemon zest — actually get baked onto the metal during the drying cycle, leaving you with more scrubbing later.

So what’s the better move? Handwash your graters right after using them — before anything has a chance to harden. Use warm water, a bit of soap, and a soft brush or toothbrush to clean out the holes safely (no sliced fingers, please). If there’s stubborn residue, soak it in warm soapy water for a few minutes and it’ll come right off.

14. Insulated mugs and containers

Here’s one a lot of people don’t realize — not all insulated mugs and containers are dishwasher safe. Sure, some higher-end ones are built to handle it, but unless the bottom clearly says dishwasher safe, you’re way better off handwashing. It might take a little extra effort, but it’ll save your favorite mug or bottle from getting ruined.

The main issue? Dishwasher heat is brutal on the seal that keeps your drinkware insulated. That seal is what traps the temperature — keeping your coffee hot or your smoothie cold. When it gets damaged, a few annoying things can start happening. Water can seep into the space between the layers, and once it’s in there, it’s nearly impossible to get out. You’ll start hearing that weird sloshing sound — and worse, it can start to smell funky over time.

Even if your mug is labeled “dishwasher safe,” frequent machine washing can still wear down the insulation performance over time. That means your once all-day-hot coffee mug might barely keep your drink warm anymore. And if you’ve invested in a premium brand like Yeti, Hydro Flask, or Stanley, that’s the last thing you want.

So, to keep your insulated containers in top shape, just handwash with warm water and mild soap. Use a bottle brush for deep cleaning and make sure to let everything dry completely with the lid off to prevent moisture build-up and odors.

15. Woks

There’s a right way to clean a wok — and it absolutely does not involve a dishwasher. Whether it’s carbon steel or cast iron, tossing your wok into the machine is one of the fastest ways to destroy that gorgeous, naturally non-stick surface you’ve worked so hard to build up over time. Once the seasoning is stripped, you’ll have to start all over again, and honestly, that’s a total pain.

Dishwashers and woks are just not friends. The detergent alone is too harsh — even a little soap can mess with the wok’s delicate seasoning, and dishwasher detergent? It’s like acid to that surface. For carbon steel woks, which are super reactive, a single wash in the dishwasher can leave you with a dull, sticky, rust-prone pan. Add in the moisture from the drying cycle, and rust starts forming almost immediately.

And if your wok has a wooden handle, that’s another red flag. The heat and humidity inside a dishwasher will make the wood swell, crack, or split — basically wrecking your handle beyond repair.

Instead, treat your wok like the kitchen treasure it is. After cooking, rinse it with warm water and gently scrub it with a soft sponge or bamboo brush (no steel wool!). If there’s stuck-on food, simmer a little water in the wok to loosen it, then wipe clean. Once it’s dry, heat it on the stove for a minute to evaporate any leftover moisture and finish with a light coating of oil. That’s what keeps it seasoned, rust-free, and naturally non-stick.

16. Potatoes

Okay, this one might sound wild — but yes, people are actually putting potatoes in the dishwasher to clean them. And while it might look clever on TikTok, it’s honestly one of the worst kitchen “hacks” out there. Even if you skip the detergent and just run the rinse cycle, it’s still a huge no-go.

Here’s why — your dishwasher isn’t exactly a food-safe zone. Even when it looks clean, there’s always soap residue left inside from previous cycles. And that soap? Definitely not something you want anywhere near your dinner. Potatoes are porous, which means they can soak up whatever’s on them — including traces of detergent. That’s not just gross; it’s potentially dangerous.

According to Poison Control, ingesting enough dishwasher detergent can cause mouth and throat irritation, stomach pain, and even vomiting. While you might not eat enough to get seriously sick, even a little residue can make your potatoes taste weird and soapy — and no one wants that on their plate.

So yeah, skip the dishwasher experiment. The safest (and honestly, fastest) way to clean your potatoes is still the old-fashioned method — a little water, a veggie scrub brush, and a few seconds under the faucet. You’ll actually get them cleaner and avoid any risk of chemical contamination.