Melissa Erickson More Content Now

This article appears in Fall Home & Garden magazine.

People often have a unique perspective about loading the dishwasher.

“Everyone thinks they’re doing it the right way,” said Kimberly Janeway, multimedia content creator for Consumer Reports.

The best place to start is the owner’s manual, “even though it’s a bit of a snooze,” she said.

While most all dishwashers are designed to fit a 24-inch cavity, manufacturers configure them differently so there are surprising differences between models, especially between American and European brands such as Frigidaire and Bosch, Janeway said.

Some basics apply to most dishwashers:

Scrape, don’t rinse

Today’s dishwashers are equipped with soil sensors that can assess how dirty your dishes are and adjust the amount of energy and water needed to clean them. For that reason, users should scrape dishes, not rinse them clean, Janeway said. Larger detritus can bounce around the dishwasher while it’s running and end up stuck on other dishes.

Scrape off cereal and clumps of food, shells, bones and objects like toothpicks. Sauces and liquids are fine left on.

“Your dishwasher shouldn’t become a garbage disposal,” Janeway said.

Pre-rinsing isn’t needed and may be a waste of water.

Start at the top

The top shelf is the place for glasses, cups and small bowls. Plastics that are labeled dishwasher-safe also belong on the top shelf.

Older plastics that are not labeled should not be washed in the dishwasher. The heat can cause the chemicals in the plastic to leach, Janeway said.

Bigger on bottom

Plates, cutting boards and serving platters belong on the bottom rack, positioned at the back or sides so that they don’t block jets from dispensing water, Janeway said.

“Cruddy casserole dishes go up front face-down,” Janeway said.

Aluminium and stainless steel pots and pans that are dishwasher-safe also belong on the bottom rack.

Up versus down

The standard advice for utensils is: Forks and spoons are placed handles-down, but knives go in the dishwasher handles-up for safety. It doesn’t really matter for dull butter knives, Janeway said, but good knives should never go in the dishwasher.

Don’t overcrowd

Water and detergent should be able to flow freely, so don’t pack in dishes too tightly.

“Detergent should be able to spring out of dispensers,” Janeway said.

Work with what your dishwasher offers by loading plates, glasses and dishes in the direction of the tines, positioning them so water is able to spritz between them, Janeway said.

And then there’s ...

People put the craziest things in their dishwashers, from car parts to bras to computer keyboards, but Consumer Reports testing finds that the dishwasher is made to clean dishes, glasses, silverware, pots and pans, and not much else, Janeway said. Other items can be ruined in or ruin your dishwasher.

Do not dishwash

— The coating of nonstick cookware can be ruined in the dishwasher, Janeway said.

— Wood cutting boards and utensils should not be machine-washed because the combination of water and heat can cause them to warp and crack, Janeway said.

— Cast-iron cookware should also take a pass because the dishwasher can remove the seasoning home chefs have built up.

— Insulated mugs may be dishwasher-safe but may lose the potential to hold their heat after dishwashing, Janeway said.