Ten things you should never put in your dishwasher

From cheese graters to anything made of crystal, these things should always be washed by hand. Photo / Getty

By Imogen Blake

A dishwasher can make your life so much easier, as it saves time as well as money on water bills.

But there are some items you should always wash up by hand, even if you are lucky enough to have one of these appliances in your kitchen, according to the experts.

From cheese graters and wooden spoons to sharp knives and anything made of crystal, these are the household utensils that the cleaning professionals at the Good Housekeeping Institute say you're at risk of ruining if you pop them into your machine.

1. CHEESE GRATERS

It's a faff to wash up graters by hand, but you'll probably have to do it anyway even if you pop yours into a dishwasher as cheese can often stick to the back of the holes in these devices.

The Good Housekeeping team advise: "Instead, use soap and a sponge to wash it by hand and ensure today's cheddar doesn't mix with tomorrow's mozzarella."

2. WOODEN UTENSILS

The hot water and pressure in a dishwasher will be too intense for anything made of wood, including spoons and chopping boards.

The heat could cause your utensils to warp out of shape and cause the colour to dull.
Instead use a drop of chlorine bleach and lots of water to scrub them clean, say the experts.

3. GARLIC PRESS

Garlic becomes sticky when it is crushed, which means it can get caught in the crevices of your press and won't wash out when you put it in the dishwasher.

It's much easier to wash it up by hand to make sure it's clean enough for your next cooking session.

4. SHARP KNIVES

Any chef will tell you to avoid putting your sharp knives in the dishwasher as the heat of the water and the chemicals in the detergent can dull the blade and even warp the shape of them.

It will also protect your dishwasher from becoming damaged, as the sharp ends of the knives can nick the plastic.

5. VINTAGE PLATES

If you've inherited any of the family china, keep it away from the dishwasher.
Hot water and detergents can chip away at hand-painted detailing and any gold trim.

6. CAST IRON SKILLETS

You should never use harsh chemicals on a cast-iron skillet so it should not go anywhere near your dishwasher.

Instead rinse and scrub with hot water, or rub clean with salt.

7. INSULATED MUGS

Normal mugs are fine for the dishwasher of course, but many insulated mugs are not built to withstand these appliances.

A dishwasher can destroy the insulated layer, rendering it useless.

8. ALUMINIUM COOKWARE

Anything that's made of aluminum will discolour in your dishwasher, according to the experts.

That includes any disposable trays as well.

9. COPPER COOKWARE

If you want to keep your copper pans, mugs and tins looking shiny and beautiful, don't put them in the dishwasher.

The heat and the chemicals can cause your cookware to discolour and dull, so hand wash them instead.

10. ANYTHING MADE OF CRYSTAL

It goes without saying really, but anything made of crystal should be handwashed.

The Good Housekeeping team write: "The high water temperature may leave your crystal chipped, cracked, or dull."

Some is dishwasher safe, but even if you do use the appliance, it can break unless you make sure it is safely secured inside the rattling machine.