15 Things You Shouldn't Put in the Dishwasher

If you're not careful, you can lose valuable kitchen tools. Keep high-end knives, nonstick pans and chopping boards out of the dishwasher.
15 Things You Shouldn't Put in the Dishwasher

Last update: 21 June, 2022

Yes, we know it saves us a lot of time. However, there are some things you just shouldn’t put in the dishwasher. Otherwise, you’ll end up ruining it.

You may not like washing dishes by hand, but when it comes to some delicate items, it’s the best thing to do. Maybe if you decide to save a few minutes on housework, you’ll have to invest in a set of dishes or other kitchen tools, or perhaps a new appliance.

Here’s a list of all the things you shouldn’t put in the dishwasher.

1. Enameled cast iron pots and pans

Beware! Although you can put most enameled pots and pans in the dishwasher, there are some that can’t. How do you know? This will depend on the brand.

The safest thing to do is to read the manufacturer’s instructions. However, if you don’t have them, choose to wash them by hand with a soft scouring pad. Otherwise, you run the risk of ruining the enamel.

On the other hand, some experts say that for cast iron to retain its properties (heat fast, transmit and retain heat well), it’s advisable to wash it with hot water without soap, dry it on the spot, and rub it with a little olive oil.

2. Non-stick pans and pots

Non-stick surfaces are very delicate. Therefore, unless recommended by the manufacturer, they should not be put in dishwashing machines.

It turns out that the detergents used in dishwashers are often very strong. This, together with the pressure jets fired by the machine, can cause pieces of the coating to come off.

It’s advisable to use a soft scouring pad and a little dishwashing liquid. The non-stick coating is a noble surface, which does not need to be scrubbed hard to ensure its cleanliness. Sometimes a wipe with a kitchen towel is all that’s needed.

Ollas y sartenes que no debes meter en el lavavajillas.
Not all cookware is dishwasher safe. Check the manufacturer’s instructions.

3. Poorly glazed ceramic or clay pots

Clay pots, if not properly sealed, are porous. This makes the piece susceptible to fracture after a trip to the dishwasher.

Pressurized jets of hot water wear down the coating of the pots. This makes them prone to incubate bacteria.

Note that the situation is aggravated if they are used at high temperatures and in humid environments. Therefore, it’s recommended to wash them by hand with a mild detergent and dry them very well with a clean cloth.

4. Things not to put in the dishwasher: Woks

Woks are kitchen utensils useful for stir-frying. They can be made of cast iron or carbon steel and a wooden handle; all of these are materials that should not be put in the dishwasher. Also, because of their bulk, they will almost certainly not fit in machines.

We think you may be interested in reading this, too: The 7 Dirtiest Places in the House and How to Disinfect Them

5. Soft plastic containers

Plastic containers can also be ruined in the dishwasher. The rule is simple: make sure they are microwave safe.

If they’re not, then they are not machine washable. Look for the image of a fork with a cup; this is the indication that the plastic is sturdy and can be washed with heat.

Otherwise, it can release toxic substances and wear out. It will warp and age quickly; sooner than stipulated by the manufacturer.

The same will be true of any plastic cookware that’s not suitable for heating food.

6. High-end knives

There is no problem with conventional knives. Not so with the knives used by chefs.

These are made of a special metal that the heat of the dishwasher can deform. The tool will become blunt and will no longer cut effectively. On the other hand, the handle also gets ruined.

7. Thermos

It turns out that thermoses are made with an internal structure that allows them to keep liquids hot or cold for a longer time. Therefore, if you put them in the dishwasher, the pressurized water could seep through the inner layers of the bottle and get trapped. This can result in mold and mildew.

8. Cutting boards and wooden utensils

The conditions in which the dishwasher sanitizes the utensils end up generating cracks in the wood. Thus, when they’re used, juices and sauces from preparations seep into the material. In addition, the wood tends to deform, shortening its useful life.

9. Aluminum and copper utensils

The dissolution of hot water with strong soap tends to negatively affect both aluminum and copper, which will cause them to oxidize over time. In that sense, it’s recommended to be prudent and not to put items made with these materials in the dishwasher.

10. Things not to put in the dishwasher: Oversized utensils

Oversized items can damage the dishwasher and ruin the utensil you wanted to wash. They hinder the rotation of the washing mechanism.

On the other hand, cookie cutters are delicate and fragile tools that do not withstand dishwasher conditions. The same goes for cake pans and bundt cake pans that have many reliefs.

11. Pressure cooker lids and rubber bands

Cooking robot parts and rubber bands in general are part of this list. These accessories are very delicate and their materials cannot withstand hot water, as they deform and lose effectiveness.

Pressure cooker lids consist of a valve with a gasket inside, which can be damaged if there are soap particles that end up clogging the area. The handle is another element that, after each wash, deteriorates and deforms.

12. Items with labels or glue

Crockery should be free of food debris and bottles should be free of labels and glue. It’s recommended that you remove any dirt before inserting the items. Otherwise, the drains, pipes, and other gadgets in the dishwasher could become clogged.

13. Italian coffee makers

Due to their structure, Italian coffee makers shouldn’t be machine washed. It’s not even advisable to wash them with detergent. Instead, it’s safest to sanitize them with hot water only.

Cafetera italiana no se puede lavar en lavavajillas.
Italian coffee makers are special because good washing ensures the production of quality coffee.

14. Things not to put in the dishwasher: Graters

Graters have an edge, just like knives. When they come in contact with hot water, they lose their edge.

On the other hand, due to the structure and the nooks and crannies of the grater, it’s best to wash them by hand to guarantee their absolute cleanliness.

15. Cups, glasses, and other glassware

In this case, we’re referring to items made of crystal, not glass. The confusion of both terms is very common.

The first is a more delicate material, so it’s usually more expensive. If subjected to high temperatures, it tends to deform and even break.

Play it safe and wash them by hand. However, some dishwashers have programs for this type of material.

We think you may also enjoy reading this article: 10 Tips to Take Care of the Environment at Home

Beware of dishwasher “special programs”

Some dishwashers come with special programs that indicate their capacity to wash some of the utensils on the list. However, the truth is that you run the risk that the results will not be as desired and your precious items will still be ruined.

Whatever you decide, you should know that the lower part of the dishwasher is the one that reaches the highest temperatures. It’s also the area where the utensils come into the most contact with the detergent. Therefore, it’s advisable to put fragile items in the upper drawer.

This text is provided for informational purposes only and does not replace consultation with a professional. If in doubt, consult your specialist.