7 Common Dishwasher-Loading Mistakes That May Surprise You

Brought to you by the researchers who spend their time studying the mysterious mechanics that happen behind the closed dishwasher door.

Of all the complicated things we have to contend with in day-to-day life, if you own a dishwasher then how to properly load it may seem trivial at best. But bear with me. If an efficiently loaded dishwasher means not having to pre-rinse your dishes or re-wash ones that were not cleaned well enough the first time, then that saving of resources actually does mean something.

And while the mechanics of it all may seem simple enough, the interior life of a dishwasher is a bit more complicated than (doesn’t) meet the eye, according to researchers who devote their time to such things – like in this study, Positron Emission Particle Tracking (PEPT) for the analysis of water motion in a domestic dishwasher. For example, the water jets directly hit just a few areas, most of the water coverage occurs when it cascades back down. “The distribution of water inside a commercial dishwasher is very chaotic,” says Dr. Raul Pérez-Mohedano, one of the authors from the PEPT study.

“Current commercial dishwashers also show a problem of symmetry – while the ejection of water is produced in a circular movement, the distribution of the crockery follows a rectangular pattern,” he adds. “This automatically produces areas where the impact of water is going to occur for longer.

So what to do with these carefully gleaned observations? Clean up your bad dishwashing habits, or course. We already have a collection of great ideas to help with the basics – 10 tips for making your dishwasher more efficient – but the following items break it down to the nitty-gritty of what many of us are doing wrong when it comes to what should go where inside that mysterious cavern known as the dishwasher.

1. Putting carb-covered dishes just anywhere

This is the stuff of joy for the true domestic engineer. Dishes that have seen carbohydrates – think pasta, oatmeal, potatoes, sweets – should be placed in a circle in the middle of the dishwasher, following the rotating sprayer arm. Carb-based gunk is best dealt with when in direct line with the water stream since it requires less chemistry and more mechanical action.

2. Putting protein-crusted dishes just anywhere

On the other hand, tableware with protein-based gunk – think eggs, melted cheese, meat mess – prefers an initial swelling/hydration stage, which is incited by the high alkalinity at the beginning of the wash cycle. If these dishes are placed around the edges of the dishwasher, they are hit with less mechanical water action and are allowed a longer time to soak, which they like.

3. Letting spoons (and forks) spoon

If you like your silverware to cuddle, it won’t get clean – the water needs space and can't find it if the cutlery is nestled together. If you have a cutlery basket that allows each piece its own place, use it. If not, load pieces in the basket alternating one headed up, one headed down. (And it can't hurt to point the sharp things down when alternating.)

4. Not facing bowls towards the water jet

If you place a bowl (or the dirty side of a plate) facing outwards on the edge of a rack, its back will get nice and clean. To actually clean the interior of a bowl, place it facing the center or a water jet.

5. Placing containers belly-up

All it should take is a few times of opening the dishwasher to see a small pond of dirty dishwater inhabiting the belly of a right-side-up bowl or lid to rid you of the habit of loading them this way, but apparently that doesn’t stop some of us from doing it. Place concave items pond-side down.

6. Overloading

You want to maximise the load; you don't want to load the dishwasher twice. Alas, overloading the dishwasher is is "the worst thing you can do for dishwasher performance," according to Kenmore engineers. That said, it's not efficient to run an underloaded dishwasher as well; find the happy balance.

7. Not following directions

Appliances come with manuals, but since we all know how to use a dishwasher, the handy-dandy dishwasher manual may be one of the more neglected piece of how-to literature known to man. But read it! And follow its sage wisdom! Each dishwasher is different and its playbook will best instruct you to what it likes.