17 Things You Should NEVER Put In The Dishwasher

What would we do without our beloved dishwashers? They certainly make meal times convenient, but that's not to say we should put everything and anything inside them.

Although there's a lot our dishwashers can handle, the hot temperature, powerful water and detergent mean some things should never be put inside.

Our list of 17 things you should never put in the dishwasher will get any confusion all cleaned up for you.

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1. Don't put your garlic press in the dishwasher

It's often tempting to put the things that are hardest to clean in the dishwasher, but those are often the things that absolutely shouldn't be in there.

The pressure created by a garlic press often leaves garlic pieces stuck on the inside. These pieces are wedged in so well that even the strong current of your dishwasher will struggle to remove them. It's much better to wash garlic presses by hand to ensure all garlic is removed and they are truly clean.

2. Wash your chef knives by hand

Top quality knives don't come cheap. If you've already invested in a set or are thinking about it, make sure you look after them properly.

Throw them into the dishwasher, and the abrasive detergents will wear down the sharp edges. They're also prone to move around in the wash, and these bumps won't do their sharpness any good either.

3. Don't put copper in the dishwasher

Let's face it, you didn't buy copper cookware for its heat-conducting properties alone. New copper looks stunning - let's try and keep it that way.

If you want to preserve their look for as long as possible, the last thing you should do is put them in the dishwasher. This will alter their colour, making them mottled and even giving them a rusty appearance - not exactly the interior dream you had envisioned.

Instead, try cleaning it with ketchup!

4. How to wash antique plates

Antique plates, your Granny's old cooking pot or anything that's old or has sentimental value should not be put in the dishwasher.

Many older items existed at a time when dishwashers were yet to be invented, and so they're not as hardy as those sold today.

Wash these items by hand, and admire their beauty while you're at it!

5. Are plastic containers dishwasher safe?

It's a good question, but not one that has a straightforward answer. Much like plates, some plastic containers are deemed 'microwave and dishwasher safe'. This is usually marked on the bottom of the box.

Others, however, cannot withstand the temperatures of a dishwasher. Wash them, and the plastic may melt or the chemical composition of the plastic may be changed, making it unsafe to use in the future.

The same goes for takeaway boxes, which should never be put in the dishwasher unless stated by the restaurant.

6. Can you put wooden chopping boards & utensils in the dishwasher?

Wooden chopping boards and utensils are no different to any other wood - they should be kept as dry as possible.

To prevent wood from becoming saturated with liquid, it's best to wash them by hand. The high temperatures in your dishwasher can also cause splinters, another reason to avoid washing them in this way.

7. How to wash crystal glasses

Having to replace chipped crystal probably isn't a situation you want to find yourself in.

The easiest way to avoid it is by:

1. Only having careful guests over for dinner
2. Washing your crystal by hand

Whilst number one mightn't always be possible, number two certainly is. The dishwasher won't do crystal any good - high temperatures and strong detergents can cause chips and even dull their sparkle - what's crystal without sparkle!?

8. Can you wash a pet bowl in the dishwasher?

This is a tricky one! Dishwashers are supposed to get hot enough to kill the majority of germs, but the NSF found 67% of pet bowls still had Salmonella bacteria even after dishwashing. This bacteria will be washed into the water, and then swirled around, contaminating other items.

If you do want to put them in the dishwasher, we'd recommend giving them a hand wash first. 

9. Cast iron pans

The beauty of cast iron pans is that sensational seasoning that gets built up over time on the bottom of the pan. This not only makes your food taste amazing, but also prevents it from sticking.

Put these pans in the dishwasher, and that coating will be destroyed. The harsh detergent will wash it away entirely, and you'll be left with a bare cast iron surface that shows signs of rust.

10. Labels may block your dishwasher

Any labels left on packaging, jars or plates should be removed before being put in the dishwasher.

If not, you risk them becoming trapped in the filter and blocking the machine. Life without a fully-functioning dishwasher just isn't worth the risk.

11. Don't put filthy pans in the dishwasher

Sometimes, there's nothing for it but a hot soak, a bit of elbow grease and a whole lotta fairy liquid.

For filthy pans coated with grease and burnt on food, this is the best option. Although dishwashers are great, they're not miracle workers, and there's some dirt that even they'll struggle to shift.

12. The dishwasher will ruin non-stick pans

Non-stick coatings are literally a godsend. Most of us know not to use metal utensils in our pans, or abrasive sponges to scrub them clean, but did you also know they shouldn't be put in the dishwasher?

Similarly to cast iron pans, the detergent and high temperatures will wear down that non-stick coating over time, ruining your beloved set of pans.

13. Aluminium will not fare well in the dishwasher

Just like copper, aluminium items will not fare well in the dishwasher. They may become scratched, lose their shine and quickly start looking worse for wear.

Be sure to check your aluminium items are deemed 'dishwasher safe' before taking any chances.

Find out how to clean aluminium in our other article, and give the dishwasher a miss!

14. Can you put washing up liquid in the dishwasher?

Putting washing up liquid into the washing machine may seem like a reasonable idea, but I wouldn't try it if I were you.

The swishing action of your dishwasher will turn that small squirt of washing up liquid into a bubble bath that quickly seeps out onto your floor - yikes!

15. How to wash insulated mugs

Insulated mugs and dishwashers don't go well together. Depending on the quality of your mug, you could find water seeping inside the insulated later.

This will linger, providing the perfect moist environment for germs to multiply. It will also make the insulation much less effective, as this is designed to be an empty vacuum layer.

16. Cheese graters should be washed by hand

Just like those little bits of garlic in your garlic press, cheese crumbs will get stuck in and around your cheese grater - a tough job for your dishwasher to tackle.

To avoid pieces of hard cheese being left on your grater, it's best to wash by hand.

17. Don't put repaired crockery in the dishwasher

You may have managed to piece and glue together that beloved China plate once, but it's unlikely you'll be as lucky a second time.

Don't push your luck by putting repaired items in the dishwasher. The glue will weaken and leave you with shattered shards all over again.

Next, read our article on how long dishwashers last - it might surprise you! For more dishwasher tips, check out what to do if your dishwasher isn't drying or your pods aren't dissolving. 

What do you hate washing by hand and always put in the dishwasher? Tell us in the comments below!