14 Things That Should Never Go in the Dishwasher

If you’re like me and would rather do almost anything than hand wash dishes, you probably rely heavily on your dishwasher. But before you start loading up, let’s talk about a few things that should never make their way in there.

Without a doubt, my least favorite household chore is hand-washing dishes. That makes my dishwasher the one appliance I can’t live without. I love it. In fact, I have this motto that if it can’t go in the dishwasher, I don’t need it.

Despite my best efforts, I still end up having to hand wash a few things since I have learned the hard way that certain items should never go in a dishwasher. They can be ruined, or they can ruin a machine. You should hand wash them instead.

1. Wood

You’d be amazed how well I could fit wood cutting boards, bowls, and utensils made of wood or with wood handles into my dishwasher. But what was I thinking? I’m careful not to expose my wood floors to standing water because that’s just asking for trouble. But these small items made of wood might somehow be impervious to the brutality of super hot water plus detergent followed by blistering high drying heat. So wrong!

The bottom line is that water causes wood to swell and distort. Detergent strips the wood’s natural oils, causing it to crack. Wood needs to be hand-washed and dried quickly.

When you need to disinfect, use a mild solution of one gallon of 70 F (cool) water plus one teaspoon of liquid bleach in a spray bottle. Spray the surface, allow it to sit for a few minutes, and then rinse and dry. That does the trick.

2. Cast iron cookware

Cast iron skillets and pans are awesome, and they will last forever if cared for properly. The secret is in the seasoning and patina that build up over years of cooking and proper care. One trip through the dishwasher can destroy all that, leaving a rusty, dull, ugly mess.

• MORE: My Hate-Love Relationship with a Cast Iron Skillet

3. Fine china

For every letter I will receive telling me that for decades you’ve washed your fine china in the dishwasher, I can show you dozens of letters from readers who wished they’d known to never do that.

High heat and harsh detergent are tantamount to sandblasting that delicate gold metallic trim, finish, and image. You might get away with it once, but why push your luck?

Handwash vintage china, especially those pieces that may have been repaired. Glue melts.

4. Aluminum

This is painful. I had no idea! Of course, it’s right there in the fine print of my Kitchen Aid stand mixer’s owner manual: DO NOT put attachments in the dishwasher! Hand wash only. Had I known, I would not have made that purchase in the first place.

It wasn’t until my hands turned black inserting that paddle in the machine (I thought the thing was leaking oil or something) that I learned the ugly truth: Some KitchenAid models come with attachments made of anodized aluminum.

Putting aluminum in the dishwasher causes it to oxidize, creating ugly dark stains and eventually pitting after many sessions.

Here’s the rule: Never put anything made of aluminum in the dishwasher. Hand wash and dry only.

• MORE: 14 Best Homemade Cleaners That Really Work

5. Crystal

Delicate crystal is no match for the rigors of a dishwasher. You’ll learn this when you notice chipping along the rim. Lead crystal will become cloudy and pitted because harsh detergents will permanently etch the surface of what used to be clear and sparkly. Carefully hand wash the crystal.

6. Copper

7. Knives

I’m going to say straight up that I hate this self-imposed restriction. I’m one to load up all of my kitchen knives into the dishwasher. And that’s about the worst thing I can do to them for three reasons:

1. The sharp edges can nick the protective coating on the racks and tines of the dishwasher, causing rust.
2. I’ve cut myself more than once when unloading the dishwasher by mindlessly reaching in and grabbing knives
3. Dishwashing detergent dulls the sharp edges of the blades, causing handles to loosen and, if they’re wood, to split.

8. Graters

For many of the same reasons as knives, cheese graters should be hand-washed. More than that, all those small holes, when graters and such are crammed into tight spaces in the dishwasher, impede the water stream necessary to clean the entire dishwasher’s contents properly.

9. Thin plastic

If you recycle butter tubs, cottage cheese, and deli containers, putting them through the dishwasher is likely to cause them to warp or even melt.

Handwashing is recommended for the best outcome. However, if you can’t be bothered (opting instead to throw these containers out instead of dealing with that extra chore), place them on the top rack of the dishwasher only. Then, remove before the drying cycle so they can air dry.

10. Snap-on lids

There are many brands of plastic containers with the new hinged snap-on lids, including Snapware. Have you noticed that over time, the lids stop snapping? Uh-huh … the dishwasher. If you want them to keep performing as well as they did when new, hand-wash only. Sorry.

11. Painted glassware

Right now I am thinking of my beloved 2-cup Pyrex measuring cup. It served me well for many years, having made hundreds of trips through the dishwasher.

Recently, I realized I could no longer read any of the measurements. The lines were so faint that I was certain my eyesight was failing me. Nope. The paint had slowly disappeared from the hands—I mean sprayer arms—of my dishwasher!

Looking back, this isn’t the first time I’ve unknowingly ruined something with delicate paint, patterns, or labeling.

• RELATED: 26 Surprising Things You Can Get Sparkling Clean In Your Dishwasher

12. Hollow handled knives

Yes, there is a way to put silver flatware in the dishwasher without harming it, but the process is tedious. One slip-up will make you wish you’d never tried it.

The one exception is silver hollow-handled knives. Never put knives with hollow handles in the dishwasher. The heat of a dishwasher, combined with the detergent, will melt the glue that holds the blade to the handle—a heartbreaking situation you want to avoid at all costs.

• MORE: House Rules for Cleaning Silver in the Dishwasher

13. Labels

If it has a label—paper, decal, plastic, painted—it should not go into the dishwasher. Not only will dishwashing degrade and eventually ruin it, but if it’s made of plastic or paper, expect that label to end up all gooey and terrible in the filter and, eventually, the dishwasher pump. Now you’re looking at a big repair bill. You can prevent this.

14. Heirlooms

When I think of heirlooms, I can’t help recalling Hummel figures. Remember those? You may have some or other similar collectibles you’ve inherited. They can really collect the dust, can’t they? The easiest way to counter that problem is to load them into the dishwasher. Right? Wrong.

If you want to protect and preserve them (so you can unload them on the next generation) hand wash only. And not just the Hummels. Anything antique, delicate, intricate, and well-loved—take the time to hand wash.

• MORE: 27 Surprising Things You Really Can Clean In Your Dishwasher

 

Question: Do you have any dishwasher horror stories from learning the hard way what not to put in there? Any surprising items you’ve discovered can actually be cleaned safely in the dishwasher? Let me know in the comments down below.

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