Home Decor

15 Things You Should Never, Ever Put in the Dishwasher

Read this before your next cycle.

September 11, 2019
Photo by Rocky Luten

My motto when shopping for home goods is, “If it doesn’t go in the dishwasher (or washing machine), it doesn’t go in my house!” Washing dishes is one of my least favorite chores, so I do my absolute best to keep hand wash-only items out of my cabinets.

But despite my efforts, there are still a number of kitchen essentials I end up hand-washing, typically because I didn’t read the fine print when I bought them. (Seriously, who knew box graters shouldn’t go in the dishwasher?)

If you’re guilty of skipping the fine print, too, you might not realize that a few core kitchen items are actually only supposed to be hand-washed. To keep your tableware, cookware, and other kitchen accessories in top shape, make sure to keep these 15 things out of the dishwasher:

1. Cast Iron

Hopefully this doesn’t come as a shock, but your cast iron pans should never go in the dishwasher. In fact, you shouldn’t even use soap on them if you can help it. Soaps and abrasive sponges can damage the finish and seasoning of your precious pan, so stick to using coarse salt to scrub it down.

Join The Conversation

Top Comment:
“I put both my box grater and microplane in the dishwasher, no problem with either. I also put my wooden utensils in the dishwasher on the top rack. They're cheap enough, so that when one warps and breaks, I can easily replace it. I also put those 'disposable' storage containers and Tupperware in the dishwasher, again top rack only. Why have the damn thing, if you're not going to use it? ”
— Marla K.

If you do accidentally wash your cast iron pan with soap (my roommates have done this to me before), don’t stress. It’s easy enough to reseason cast iron—you just need to oil it up, and bake it in the oven.

2. Nonstick Pots & Pans

The reason it's said you should never use metal utensils on nonstick pans is that they can damage the finish, ruining the effectiveness of the nonstick surface. The same thing can happen if your pots and pans get banged around in the dishwasher—the surface can get scratched, shortening its lifespan.

3. Crystal

Crystal glasses are delicate, and the high heat and/or water jets in your dishwasher can cause chips or cracks. Even if they do make it through the cycle, your glasses may develop a cloudy residue over time—so stick to hand-washing crystal and fine wine glasses.

4. Wooden Cutting Boards & Utensils

Wood and dishwashers just don’t mix. The heat of the dishwasher can cause wood to warp, and the drying cycle can make it crack. So please, keep your wooden cutting boards and utensils out of the dishwasher.

5. Insulated Travel Mugs

Most travel mugs have a special vacuum seal between the inner and outer shells, and this seal can be ruined if you put the cup in the dishwasher. Not only will this compromise the effectiveness of your best travel mug, but you may also get water in the walls that sloshes around as you drink.

6. Copper Pans

Copper is prone to tarnishing, and the harsh conditions of the dishwasher can ultimately ruin the shine of your beautiful copper pots and pans. Given that they’re typically quite pricey, I think it’s worth hand-washing them to protect your investment.

7. Your Best Knives

Of course you can put your butter knives in the dishwasher, but you might want to think twice about putting good kitchen and prep knives through the cycle. Why? The harsh conditions of the appliance can dull the edges of blades, forcing you to sharpen them more frequently. It can also cause carbon steel and other materials to rust.

8. Graters

There are two reasons to wash graters by hand. First, similar to with knives, the dishwasher can dull graters' blades. And second, chances are, a dishwasher won’t be able to get all the particles out of their little holes, so you’re better off doing it by hand anyway.

9. Aluminum Pans

Both aluminum cookware and disposable aluminum trays will become discolored when put into the dishwasher, if not sealed in some way. The metal can react with water and air in a process called oxidation, and becomes covered in a dark film that then rubs off on other items.

10. Pressure Cooker Lids

While technically the top of your Instant Pot is dishwasher-safe, it’s not the best cleaning option, as there are a number of important components in the lid of a pressure cooker. For instance, there are values that can get clogged with food particles, as well as seals that may be damaged by the dishwashing chemicals—both of which will shorten the lifespan of your appliance.

11. Milk Glass

The pure white hue of milk glass makes it a treasured collection piece for many, and it’s important to learn how to care for this material properly if you want it to last. Milk glass can take on a yellow tint if put in the dishwasher too many times, so you’ll want to wash it carefully with a gentle cloth and soapy water.

12. Thin Plastic Containers

Unless you know for a fact that a plastic container is dishwasher-safe, I’d recommend scrubbing it down the old-fashioned way. Thin plastic will sometimes melt or warp in the dishwasher, rendering the container useless—a lesson I’ve learned the hard way.

13. Pop-Top Storage Containers

Airtight storage containers are a must-have in any pantry, but when it comes time to clean them, the dishwasher is a gamble. Many say they’re dishwasher-safe, but the gaskets can warp and seals can break down if you wash them frequently.

14. Family Heirlooms

In general, it’s best to leave anything precious that's missing cleaning instructions out of the dishwasher. This applies to fine china, your grandmother’s favorite mixing bowl, or whatever else you hold near and dear. Don’t risk it getting dinged in the dishwasher!

15. Items with Labels or Adhesives

If you’ve ever put an empty pasta sauce jar through the dishwasher (guilty), you know that the label comes out a torn, soggy mess. Not only will the hot water ruin the label, but the pieces that flake off can clog your dishwasher’s filter, as well.

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See what other Food52 readers are saying.

Freelance writer, product tester & baking enthusiast.


Joe July 24, 2023
Most things I agree with you on. Some exceptions though.
I’ve been putting my box grater in the dishwasher for at least 20 years. Check it when it comes out and cheese all gone.
I knowingly shorten the life of my $60 to $100 dollar non stock pan by putting it in the DW. Typically I replace them every 7 to 10 years and buy new ones. Typically at Winners or a similar place at a fraction of the regular price. Works for me - I hate washing dishes too!!!
eli7 June 16, 2023
Sterling silver or sliver plated silverware should not go in the dishwasher. The finish is eaten away by the dishwasher detergent.
[email protected] March 16, 2023
I don’t use plastic much in my kitchen. If it can’t go in the dishwasher, I won’t use it. Seems to me impossible to get rid of dish detergent smell from plastic, especially if grease is involved.
Laura L. March 15, 2023
Vintage PYREX! I have always hand washed my primary bowl set for nearly 40 years, but made the mistake of putting Butterprint pieces from my husband's family in the dishwasher, and now they have DWD (dishwasher damage). Don't make my mistake - PYREX prices are now astronomical!
Karla P. March 15, 2023
Wooden utensils and anything with a wooden handle.
baileychic8 July 2, 2021
Car parts. My ex is a mechanic.
Gina G. March 1, 2021
Pls do not put any item with a rubber gasket in, something like the lid for your Sous Chef or glass storage jar or blender cover or blade seal. They warp or melt and never seal properly. And you won’t believe what a lengthy and expensive hassle it can be to replace that Sous Chef lid!
BoulderGalinTokyo February 28, 2021
After years of helping exchange students and other foreign language learners I really have to teach dishWASHER soap and Dish washing liquid as soon as they move in. One lady filled the dishwasher soap holder and she had bubbles throughout her entire living room!
Alex S. February 28, 2021
When I shared an apartment with my college-aged brother, and we ran out of dishwasher soap, we sometimes tried to use a tiny amount of powdered laundry soap. It could cause the same disastrous results as the lady and her living room. Those excess suds really cleaned the kitchen floor though!
Nkolew December 1, 2020
Sooooo, then basically nothing in your kitchen can go in the dishwasher? The designers should probably change the designs of dishwashers then.
Melissa August 21, 2020
Silver As in actual "silver" ware
Caroline L. March 2, 2021
Silver is fine to go in the dishwasher if you follow the rules - no lemon detergent, no heated try, don't let it touch anything stainless steel. Some people don't put the knives in because of the glue holding the blade and handle together, but it takes a very very long time for that to be an issue.

If it's the difference between using it and leaving it in storage, I absolutely encourage people to wash sterling in the dishwasher. Estate silver expert Beverly Bremer gives it the OK, which is good enough for me. It can get a little cloudy over time, but no faster than it would take to tarnish - so I'm happy to polish it off when that time comes.
Miche March 7, 2023
I read something of the sort shortly after I inherited my grandmother's silver and started putting it in the dishwasher. It soon started looking terrible and needed a lot of polishing, which is much more onerous that washing. It's relatively easy to handwash flatware, and I highly recommend it for sterling.

Nancy March 12, 2023
Another way I learned to safely wash silver in the dishwasher is WITHOUT any stainless steel in the same load.
Marla K. December 29, 2019
I put both my box grater and microplane in the dishwasher, no problem with either.

I also put my wooden utensils in the dishwasher on the top rack. They're cheap enough, so that when one warps and breaks, I can easily replace it.

I also put those 'disposable' storage containers and Tupperware in the dishwasher, again top rack only.

Why have the damn thing, if you're not going to use it?
J December 31, 2022
I agree, Marla. For box grater, microplane, or the several types of mesh sieves/colanders I use, I just brush off the goop with a scrubbing brush under warm water before I put it in the dishwasher: do this before the goop dries. For plastic food storage containers, the dishwasher is preferable because everything will be far more sanitary than with hand-washing, and sanitized containers are essential for safe food storage. Finally, my wooden spoons and spades, most of which I’ve owned for decades, always go in the dishwasher. Their micro nooks and crannies also need the dishwasher’s sanitization, which simply can’t be achieved with hand washing.
Miche March 7, 2023
I agree! Wooden spoons never feel really clean if washed by hand. I have a decades-old wooden spoon that has been exclusively dishwasher washed and never split or broken.
Pheline May 17, 2023
I recall a discussion online years ago where people from humid places said well… if you make sure your wooden stuff dries, it's probably ok while those of us from dry areas said, well … if you oil your wood when it gets too dry you can probably wash it in the dishwasher.

I'd rather make sure my wood tools are genuinely clean than keep them out of the dishwasher for worry about hypothetical damage.

My baking stones … I always wiped them off with a damp cloth as soon as I removed the food and they were great. My partner, OTOH, I don't know what he does but I don't think he does anything with them and they look terrible. I'm thinking of putting them in the dishwasher with baking soda and see if that helps. I'm not sure if detergent is a good idea though.

arcane54 December 25, 2019
The cloisonné brasswork your grandfather picked up in the Middle East when he was a merchant seaman in the 1940s. Just. Don’t.
jpriddy October 20, 2019
Reading through comments, I would add simple advice: Do not allow guests to "help" by loading the dishwasher. They will put things in that you do not washed as well as loading the dishwasher in ways you do not want it loaded. I recall a serious argument when a friend insisted on putting my wooden spoons in the dishwasher and I took them back out. Now we just say no-thank-you to people who offer to help.
Liz C. December 29, 2019
Your comment reminded me of a story. My grandmother got a dishwasher before the rest of the family. It wasn't until I moved out that anyone else had one. So the next time we were all cleaning up after dinner I loaded the dishwasher. My mother and aunts all stood back and held their breath. I didn't know but apparently, my grandmother never let anyone load the dishwasher. I passed :)
ThePickledFig March 1, 2021
Everyone definitely has their way to "best stack a dishwasher". The University of Birmingham even codified these bitter arguments in a paper too! They found 42% of people reload their dishwasher because they believe it is done incorrectly. IMO, it is easier to designate who in the family loads it and leave it at that. When I go to my parents house, my mom loads it; when she is at my place she knows I load it. We are both horrified by how we each load our machines (for example, I am not in the camp of overstacking a dishwasher - all items must easily be hit by water; my mom, however, fills every space available before running!). Agreed, it's also ok at to tell guests no to helping or, if quiet spoken, just reload after they leave - no rule the dishwasher must be run after loading =) Honestly when it comes down to it, everyone has items they are ok or not okay going into the dishwasher. For example, the cheap wooden spoons I get at HomeGoods go straight into the dishwasher because they are easy to replace. The pricey and unique wood serving piece that I want to last for years is hand washed.
Roberta October 18, 2019
Don't wash stainless steel and sterling silver in the same load. Better yet, don't put sterling silver in the dishwasher.
pat October 18, 2019
salad spinners-
Barbara R. October 29, 2019
Why not? Just curious what might happen to the salad spinner. It seems like it might be okay?
pat October 29, 2019
mine says do not wash in Dishwasher.. but additionally i try to avoid putting anything plastic in the dishwasher: i saw this: The chemicals found in certain plastics can be harmful to kids when heated. ... Because heat can cause plastics to leak BPA into our food, the AAP suggests not microwaving food or drink (including infant formula and breast milk) in plastic and to avoid putting plastics in the dishwasher altogether
Liz C. December 29, 2019
Yes, I'd really like to know how much of the toxins found in our water system came from washing plastics in dishwashers. BPA, formaldehyde, etc.
liz S. October 18, 2019
Other no-no's include anything with gold rims: the detail on my glass salad bowl almost disappeared after a friend dw'd it without asking me.
leslie F. October 17, 2019
Anything that has candle wax on it!—the little plates, the glassware candlesticks, any and everything that our lovely wax candles dripped upon LOVES the high heat of dishwashers and spreads a lovely wax coating on every, single, wingle thing in your dishwasher. And once gone through dryer mode, it’s all nearly impossible to clean off.
So do not put candle wax in the dishwasher. (And while we’re on it, not the washer either. Creates a similar nightmare.)
Fred K. October 17, 2019
I read through all the comments looking for this additional reason to never put aluminum in the dishwasher: little bits of it will migrate to china and remain there, waiting to be laboriously scrubbed off!!!
kat October 17, 2019
How about all the things I put in the dishwasher?? I took a small cat carrier apart and ran it through my dw. Perfect! Also I have some sandals that are made of some extruded plastic/or other strange lightweight material--they are great to run through dw after a trip to Mexico.
AlwaysLookin October 17, 2019
You should FLAG this, 'not for experienced cooks' ... most aren't this silly to think they should wash these items in a Dishwasher.
Janet C. October 18, 2019
You would be surprised what experienced cooks don't know. I have a friend that would think nothing of doing most of the above and she's been cooking for decades. Yes, she lives under a rock, but then I have another friend who argued with me about how many tsps make up a T. She's also been cooking for years. I bought her a conversion chart.
Pheline May 17, 2023
Hence my reference to the know-it-all who apparently thought her black grime-covered griddle was seasoned and not just icky.