I'm a dishwasher expert - here's five things I'd never do when stacking my machine

How to load a dishwasher must be one of the most hotly-debated household subjects – and a cause for many an argument. 

From the arrangement of the plates to the position of the cutlery, and even where to put the tablet, there's no shortage of contentious issues. 

Now, in an effort to put the debate to bed, an expert shares five things he'd never do when stacking his machine. 

Andrew Laughlin, a researcher at consumer champion Which?, said common mistakes include not taking the time to stack properly. 

Laughlin also reveals whether it's a good or bad idea to pre-rinse your dishes – and whether or not it means they come out cleaner. 

'Every year, we put more than 60 consumer dishwashers through our rigorous labs tests,' he said. 

'But I'm a dishwasher user too, with my own preferences as to how things should be done.

'These are things that I wouldn't do with my dishwasher – either because they're not necessary, or could even mess up how your dishwasher works.'

PRE-RINSING PLATES

It's one of the most common mistakes people make when stacking their machine, and also one of the most pointless. 

According to the expert, there's no reason to pre-rinse your plates before you stack them, no matter how heavily stained they are.

As long as you have scraped off any food leftovers into the bin, you can stick your dishes straight into the dishwasher rack. 

It's a myth that rinsing plates off before putting them in the dishwasher means they will end up cleaner. 

'For some, the thought of not rinsing plates before loading them into the dishwasher will fill them with horror – but I never bother rinsing crockery,' Laughlin said in a Which? blog post. 

'Most dishwasher programs pre-rinse your dishes, so you won’t need to waste water and money by running them under the tap.

'Modern, all-in-one dishwasher tablets are more than capable of taking on any mess thanks to a combination of powder and gel-based detergents.' 

According to a 2020 study by Fairy Liquid, 36 per cent of dishwasher users in the UK rinse dishes by hand with soap and water before loading into the dishwasher. 

USING THE DETERGENT DISPENSER 

Putting the dishwasher tablet securely into its little dispenser is part of the loading routine, but it's actually not necessary. 

In fact, too many times a semi-dissolved tablet is still in there at the end of a cycle because the dispenser hasn't opened – leaving our plates, cups and bowls unclean. 

According to Laughlin, a more effective tactic, which also saves time and fuss, is just bunging the tablet straight into the body of the dishwasher.

'You might worry about the detergent getting washed away in the pre-wash,' he said. 

'Sure, dishwasher tablets start to dissolve on contact with water – as anyone who has reached into the bag with wet hands will know.

'But most modern tablets won't be fully dissolved in the pre-wash cycle

'Plus, it's part of the cleaning cycle, anyway.' 

STACKING RANDOMLY 

Haphazardly stuffing all your plates and bowls into the machine in a disorganized fashion may be a technique employed by many – especially when pressed for time.

But this is a big blunder that can prevent your crockery from coming out shining clean.

Dishwasher owners should always stack plates and flat items facing inwards – with the stained side towards the rotating spray arms at the bottom.

Water pressure down the bottom is higher, meaning delicate glass items or light plastic containers should be placed in the top rack – so they don't break or get knocked around. 

'Pots, pans, deep bowls and other such items should face down,' said Laughlin, adding: 'Make sure no large items are placed in a way that will block the spray arm.'

'Don't overfill the dishwasher, and make sure you space out dishes and cutlery so that the water and detergent can reach the whole load.' 

'On the whole, anything that needs harder cleaning, such as baking trays or pots and pans, goes on the lower rack where the water pressure is higher,' the expert said. 

Some dishwasher users like to see how much they can fit in there in one go, but it's key to ensure plates aren't touching. 

SKIPPING MAINTENANCE 

The expert also said he would never skip dishwasher maintenance to keep it in the best possible shape and prolong its lifespan. 

Essential maintenance includes topping up your salt at least monthly – which softens the water to help prevent limescale build-up and make your glasses gleam. 

Depending on how many washes you do you may also have to fill up the rinse aid every few weeks.

Rise aid lowers the surface tension of water, so it more easily slides off dishes in the dishwasher and can drain and evaporate away. 

Meanwhile, regularly cleaning the filter – at least monthly – can also help prevent build-up of left-over food, bad odours and filthy plates. 

LOADING WOOD OR SHARP KNIVES 

Lastly, some items just should never go in a dishwasher because they can get damaged, even from one cleaning cycle. 

Wooden items like spoons and chopping boards can swell and splinter due to the water exposure, while blades of sharp knives can be dulled. 

'Non-stick items and most insulated mugs are also a no-no as dishwashing can ruin special coatings and vacuum seals,' Laughlin said.

The expert also names three things he would do with his dishwasher – including taking the time to load efficiently. 

Also, people should make use of the adjustable racks for taller items, such as long-stemmed wine glasses, and 'use the programs effectively'. 

'Modern dishwashers have an array of programs to choose from, but typically, there's always a main or auto cycle, a quick wash and an eco program,' Laughlin said.

Main programs usually wash at a temperature between 131°F-149°F (55°C-65°C) and are designed for mixed loads, while 'auto' senses how dirty your dishes are adjusts water temperature and wash duration accordingly.

Quick, fast or 'rapid' cycles are intended for lightly soiled dishes or small loads that just need a quick clean – not intended for full and everyday loads. 

Lastly, eco or energy-saving programs are designed to use less water and wash at lower temperatures, but usually take well over three hours to complete.