It’s one of the most talked about household chores, even at Number 10 Downing Street.
And with so many ways to stack a dishwasher, it’s often confusing to know how exactly to get the cleanest result.
Do you have to pre-rinse the dishes? Does it make a difference whether you put them on the top or bottom shelf? And how exactly should the cutlery be placed?
Now MailOnline has spoken to engineers and home appliance experts to find out what science says is the best way to load your dishwasher.
Dr. Rainer Stamminger, a physicist and professor of domestic engineering at the University of Bonn in Germany, said you don’t need to pre-rinse dishes – a mistake many households make.
From where to place your cutlery to the best spot for the cleanest wash, experts reveal the best way to stack your dishwasher
With so many ways to stack a dishwasher, it’s often confusing to know how exactly to get the cleanest results. Now MailOnline has spoken to engineers and home appliance experts to find out what science says is the best way to load your dishwasher
‘It’s not necessary because it uses a lot of water and energy if done with hot water,’ he told MailOnline.
“It is sufficient to wipe food residues into the trash with a napkin or with a knife or fork.”
In general, items that are heavily soiled with stubborn food stains should be placed on the bottom shelf (where the rotating spray arms are located) because the water pressure is higher there.
That’s also why delicate glass items or lightweight plastic containers should be placed on the top rack (where the pressure is lower) so they don’t break or fall over.
Also do not place very dirty dishes in the four corners or on the shelves, because the water from the round spray arm cannot reach them properly.
“Remember that the water always comes up from the spray arms, so the dirty side should be facing down,” said Dr. Stamminger.
Some dishwasher users like to see how much can fit in one go, and while there’s nothing wrong with that, it’s important to make sure the dishes aren’t touching each other.
This image shows Dr.’s six-part process. Rainer Stamminger for cleaning your plates in the dishwasher
“There should be space between the items so that the water can get through,” Dr. Stamminger added.
Kiwi Services recommends leaving a gap of 1 to 2 inches between dishes to allow plenty of room for detergent and water to circulate.
In 2015, a study led by an expert from the University of Birmingham suggested a radical arrangement for dishes in a dishwasher.
It said the most efficient way to wrap plates is in a circle, but with carb-laden dishes in the center and protein-laden dishes around the edge.
Water moves at a higher speed in the center, which is necessary to remove carbohydrate-based stains, the study explained.
Dr. Stamminger told MailOnline that he disagrees with this recommendation, although he called it “very interesting.”
“All heavy stained loads should be loaded close to the center, at least in the area well reached by the water jets from the circle of the spray arm rotation,” he said.
‘The edges only occasionally get some water splashes.’
While most dishwashers have a basket on the bottom shelf for stacking cutlery vertically, other models have racks at the very top that allow cutlery to be stacked horizontally.
Dmitry Letsman, dishwasher category manager at Hotpoint, says the top rack helps prevent dirty cutlery from sticking together during the wash cycle, ensuring a thorough clean.
In 2015, engineers tracked water movement in dishwashers before concluding that dishes should be placed in a circle, but with carb-stained plates in the center and protein-stained plates around the edge. Carbohydrate-based stains require the full force of the water jets to get clean, while protein-based foods require more contact with the cleaning chemical
But according to the expert, there is ‘no real right or wrong method’ when it comes to cutlery.
‘Normally, the upright cutlery in the basket is preferred because of the space saving, especially if it can accommodate larger utensils such as serving spoons or tongs,’ Letsman told MailOnline.
However, he urged the public never to put sharp knives into the machine, especially expensive chef’s knives, nor wooden utensils, fine china or delicate glassware.
“Dishwashers can dull the blades of sharp kitchen knives over time, causing them to rust,” Letsman added.
‘Washing hands and drying them immediately is the best way to clean them.’
If you do stack table knives vertically in the basket, Dr. Stamminger recommends, for safety reasons, to place them upside down, with the handle pointing upwards.
“If the cutlery is facing up or is cooked, it won’t affect cleaning much, but if there are small children around, it may be wise to place it upside down,” he says.
