There are a number of unexpected items you should never put in the dishwasher according to consumer choice brand Which?

While the dishwasher is very useful for cleaning a number of important utensils, you can't go about throwing any old item into the machine.

Putting the wrong item into the dishwasher can lead to non-dishwasher-safe items being destroyed.

With all this said, here are the items you should never put in the machine.The Bolton News: Canva - Which? have named 7 items you should never put in the dishwasherCanva - Which? have named 7 items you should never put in the dishwasher (Image: Canva)

The 7 items you should never put in the dishwasher according to Which?

The 7 items you should never put in the dishwasher:
1. Kitchen knives

While steel and ceramic knives are generally safe to put in the machine, the heat can make them duller and less effective.

This is why it is better to handwash them and sharpen them every now and again, ensuring they last longer. The same can also be said for blender blades.

2. Wooden spoons and chopping boards

Anything wooden can't go in the dishwasher, regardless of what type of wood it is.

The high heat can cause these items to splinter and split with Which? suggesting people wash these items by giving them a quick scrub and rinse.

3. Non-stick items

Non-stick pans and other items should be washed and dried by hand.

This is because the dishwasher can wear down non-stick surfaces, leading to your next meal sticking to the pan.

It is also recommended that you check what your baking trays are made of before you wash them in the machine.

If they are stainless steel and anodised aluminium, they will be fine but if they are cast iron or regular aluminium, they need to be hand-washed.

The Bolton News: Canva - You should never put non-stick items in the dishwasherCanva - You should never put non-stick items in the dishwasher (Image: Canva)

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4. Crystal or milk glasses

While these items can be dishwasher safe if the right precautions are taken, Which? recommends against it.

Over time abrasive detergents can mark or scar the crystal with the full-lead crystal being very susceptible to this.

However, if you really must, use a more mild detergent, and make sure none of these items are touching each other before putting the machine onto a low-temperature cycle.

5. Copper, aluminium or cast-iron cookware

While stylish copper and aluminium pots and pans can be a lovely aesthetic choice for your kitchen, they should be washed by hand.

Only anodised aluminium items are dishwasher-safe as they have a protective layer of Oxide. 

Without this, the harsh detergents can cause the aluminium to tarnish and turn black.

6. Insulated coffee mugs or water bottles

Sustained high temperatures can cause the vacuum seal of these items to become damaged, affecting their reusability.

7. Pressure cooker lids

While the actual pot of the pressure cooker can be placed in the dishwasher, never put the lid in.

The high heat and harsh jets could damage the seal mechanism, making the pressure cooker obsolete.