10 Things You Should Never Put In Your Dishwasher

Dishwashers are a must-have if you spend a lot of time in the kitchen. Instead of washing everything manually, you can just pop them in the washer. From there, all you need to do is add some soap, and off you go.

Compared to hand washing, they’re also more efficient. For one thing, they use less water when you have a full load. Not only that but they also do a better job of cleaning and sanitizing. This has to do with the fact that they use super hot water to wash the dishes, which effectively removes contaminants that are on the dirty dishes.

But did you know that there are certain things that you shouldn’t put in the dishwasher? For example, you should never put antiques in the washer for obvious reasons.

What other things should you avoid? What would happen if you accidentally run them through a wash cycle? Keep reading to find out!

10 Things You Shouldn’t Put in the Dishwasher

Without further delay, here are ten things that you should wash by hand instead.

1. Cast Iron

Cast iron cookware should never be placed in the dishwasher. For one thing, the dish soap will strip the seasoning; that will expose the interior to water and oxygen, which will cause it to rust. Not only that but soaking it in hot water will also speed up the process.

Not only will the rust make the skillet harder to use but it’ll also add an unpleasant metallic taste to your food.

Aside from rusting, the dishwasher can also ruin the pan’s non-stick surface, which typically develops over years of use. Given that, it’s best to wash your cast iron cookware by hand with hot water – that’ll help loosen any food that’s stuck onto the surface. If necessary, you can also use a soft-bristle brush.

2. Anything Made Out of Wood

Anything wood, including spoons, cutting boards, and knives with wooden handles, should never be put in the dishwasher. Not only will the dishwasher detergent scratch the wood over time, but the heat of the water and drying cycle can cause the material to warp, splinter, and crack.

There’s also a chance that the wood will soak up the smells from your dishwasher.

Given all that, it’s best to hand wash them instead. For example, you can disinfect wooden cutting boards by wiping them down with a bleach solution before washing them with hot, soapy water in the sink.

3. Kitchen Knives

Kitchen knives can easily nick the protective coating on your dishwasher racks and shelves and that can cause them to rust. Not only that but they’re also dangerous to unload due to their sharp edges, especially if you have kids helping.

What’s worse, is that it can actually compromise the integrity of your knives. For example, the water jets can knock them into your plates and pans and that can damage the edge. The same goes for the hot water; it can easily damage the knives’ stainless steel handles and blades. In some cases, they can even warp and become deformed.

Given that, it’s best to handwash them with soap and water.

4. Aluminum Cookware

Have you ever put a disposable aluminum tray in the dishwasher? If so, you probably noticed that it turned dull and darkened. Well, the same thing can happen to your aluminum pans and pots.

If the metal has not been anodized (coated with a protective layer), the dishwasher detergent can cause corrosion and pitting. Not only that but the pH of the soap can cause white spots to develop on the surface. That’s why you should hand wash all your aluminum cookware – even if it’s labeled as ‘dishwasher safe’.

As it is, the best way to clean aluminum pots and pans is with dish soap, warm water, and a soft brush. Never use steel wool or other abrasive cleaners as they can scratch up the metal surface. If necessary, you can also use silver polish to get rid of any discoloration that may be on the exterior. From there, give it one final rinse with water before drying.

Tip: You can use cream of tartar to remove spots and discoloration from your aluminum pots and pans. Just spread the paste over the surface and rub.

5. Nonstick Pots and Pans

Nonstick pots and pans are not made for the dishwasher. Even if the manufacturer labels the product as ‘dishwasher-safe’, it’s best to wash them by hand as they can still get damaged during the wash cycle.

More specifically, the nonstick coating can break down, which will defeat the whole purpose of having a non-stick pan in the first place. This has to do with the fact that many dishwasher detergents contain solvents, harsh chemicals, and abrasives, that can cause the non-stick coating to deteriorate.

What you want to do instead, is wash them with hot, soapy water in the kitchen sink. From there, you can dry them with a towel or let them air dry on a drying rack.

6. Thin Plastic

Food containers made of thin plastic should always be washed by hand – even if they’re labeled as ‘dishwasher safe’. For one thing, the high heat can cause the plastic to release harmful chemicals such as BPA, which has been linked to various health issues, including breast and prostate cancers.

Not only that but the high temperature can also cause the plastic to melt, and tiny pieces can break off and damage the dishwasher. For example, they can end up in the filter. The container itself can also warp due to the heat (the thinner the plastic the more likely it’ll happen).

And if you live in an area with hard water, it can cause the plastic to develop a white, hazy film. The minerals from the water can also cause tiny scratches on the surface, which can harbor food and residue. In other words, your container will never truly be ‘clean’.

7.  Insulated Tumblers and Containers

Insulated tumblers and containers are great for keeping cold things cold and hot things hot. The way they work, they have a layer of empty space between two walls of material (usually stainless steel or plastic). Ultimately, it’s this ‘airspace’ that insulates the food.

If you put these containers in the dishwasher, the seal between the layers can break and water will enter the air chamber. That will damage the vacuum seal and compromise its ability to maintain the temperature of its contents, whether cold or hot.

Not to mention the heat and water can also damage the seal.

Given that, it’s best to wash vacuum-sealed tumblers, mugs, and containers by hand.

8. Sieves and Graters

Graters and sieves should never be put in the dishwasher. For one thing, the dishwasher won’t be able to thoroughly clean the tools given the number of holes that they have. The sharp edges can also damage the plastic on the shelves and racks, leading to rust.

That’s not all, the small holes can also prevent the water jet from removing all the food particles from your dishes.

Instead of putting them in the dishwasher, wash them by hand with a bit of dish soap and water, just like you would with regular dishes. For the best results, clean the grater in the direction of the blade – that way, you won’t accidentally hurt your fingertips in the process.

9. Copper Mugs and Pans

Copper pots and pans are known for being aesthetically pleasing. Not only are they shiny, but the metal itself is also an effective heat conductor, meaning that heat will distribute evenly throughout the pot or pan.

The chemicals in dishwasher detergent, however, are often corrosive and can damage the copper finish. In fact, a single wash cycle can cause significant discoloration and dulling. In some cases, it can even cause the copper to pit and once that happens, it’s almost impossible to reverse.

To prevent that, it’s highly recommended that you hand wash all of your copper pots, pans, and mugs with mild dish soap.

10. Pressure Cooker Lids

It’s perfectly fine to put an instant pot inner container into the dishwasher. The lids, however, should always be hand-washed. The way they’re designed, they contain valves that allow pressure to be released while food is cooking.

If you run them through a dishwasher cycle, small food particles can get into these valves and vents and that can cause the pressure cooker to malfunction. The harsh chemicals in dishwasher detergent can also damage the silicone or rubber seals of the lid, which will compromise the airtight seal. As a result, its cooking abilities will be compromised.

And there you have it – 10 things that should never be put in the dishwasher, no matter how convenient it seems. Not only will it damage the item but in some cases, it can also damage the dishwasher itself.

When in doubt, opt for hand washing. If anything, it’s the best way to keep them clean and looking like new.