10 Things You Should Never Put in The Dishwasher

On May 31, 2017 by Josh

Dishwashers are a cherished item in the household, as they save us from many gruelling washing up tasks!

Despite their ability to tackle a huge batch, there are some things that you can’t put in a dishwasher due to the damage it can lead to your kitchen utensils and more importantly the appliance itself.

Read on to find out about these 10 things which have no place in your dishwasher.


Knives can quickly dull when placed in the dishwasher, which is particularly frustrating when this happens to your best ones. Not only does the detergent in the dishwasher wear down the sharpness of the knife over time, but the banging of the knives with other cutlery can extenuate this problem. However, some dishwashers come equipped with a knife rack, which helps to keep them protected.

Cheese Graters

Cheese graters are messy utensils, due to all the small food particles getting stuck in the tiny holes, so for that reason they shouldn’t go anywhere near your dishwasher.

These objects need to be cleaned by hand because if you place them straight into your dishwasher after using them, you’re bound to notice that it’s left some mess in your appliance. Hand wash your cheese grater to ensure that it’s clear of any loose food particles, so that it doesn’t leave any dirt in your dishwasher.

Placing dirty cutlery or objects in your dishwasher can clog the pump assembly which may leave you in need of having your dishwasher repaired.

Non-Stick Pans

Unless your non-stick pan has a label saying, ‘dishwasher safe’, then these are objects should not be thrown in the dishwasher, because they won’t last for much longer after that.

The detergent can majorly affect these pans non-stick quality and it is best that you wash these by hand.

Insulated Mugs

Despite that some new insulated mugs have been made to be dishwasher safe, some older models will lose their insulation quality when placed in the dishwasher, as the space between the outer and inner layer can fill with water.


It is commonly questioned whether you can put plastic in your dishwasher. In fact, some dishwashers can accommodate plastic cutlery, but for those that can’t, they can melt the plastic and leak harmful toxins when heated.

However, the plastics that can be problematic for your dishwasher are the weaker ones. Plastic cutting boards and mixing boards are less troublesome and can go in the dishwasher, but make sure they are kept on the top shelf so they are as far away from the heat as possible.


Whether it’s disposable or not, any objects made of aluminium that you place in your dishwasher run the risk of becoming discoloured.

This discolouration will come in the form of either black residue or marks all over your aluminium item. Or even worse…it could discolour other items in your dishwasher too.

Make sure you don’t get your aluminium cookware confused with their stainless-steel equivalent, as the latter are more than equipped to tackle your dishwashing appliance.

Gold Plated Crockery

If you have any fancy gold-plated dishware, then it’s essential that you only wash these objects by hand. By running them through the dishwasher, then there’s a chance that the gold can be eaten away …. a chance which certainly isn’t worth risking.


Crystal bowls and glasses don’t come cheap and by throwing them in the dishwasher they’re surely not going to be a long-lasting investment.

By putting crystal in your washer, the high temperature can leave it chipped or cracked. However, some manufacturers now make dishwasher safe crystal, but it’s still important to make sure that they are secured tightly in the appliance to stop them from moving around and breaking.

Objects with Adhesives

Any objects that you throw in the washer that have labels on them containing glue, can cause damage to the appliance. Either hand wash any labelled objects, or simply remove all labels before loading into the dishwasher.

Garlic Press

Garlic presses pose a similar threat to your dishwasher than cheese graters because they are messy and a nightmare to wash.

Garlic in particular can turn into a paste form and can get stuck in the crevices of the press which is not a good mix with your dishwasher. This is due to the amount of dirt it can leave within the appliance, which will worsen its washing effectiveness.

So now you know all the things that can be detrimental to the condition of your dishwasher, you have no excuse not to hand wash these items, no matter how much of a rush you are in! This way, you can prolong the lifespan of your dishwasher so it can continue saving you time for many years to come!

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