I always pre-rinse my dishes. While I’m no nutcase—I don’t actually wash them before placing them in the dishwasher racks—leaving the remains of a runny egg, clingy sauce, or (gasp) oatmeal on my crockery and expecting my Whirlpool to do the heavy lifting simply feels wrong.
But it turns out there’s good reason to avoid the temptation to rinse away lingering food particles before using your dishwasher. Most appliance and dishwasher soap manufacturers recommend against rinsing every remnant of food off your dishes, saying doing so can actually inhibit proper cleaning. Here’s why.
Why your dishes need to be dirty to get clean
Perhaps the reason so many of us pre-rinse is because that’s how our mothers did it. But dishwashers have come a long way from the ones our parents used. According to Consumer Reports, “pre-rinsing isn’t necessary with modern dishwashers because they have sensors that adjust the wash cycle based on how dirty the dishes are.” They don’t need our help, and by pre-rinsing “you could be making matters worse by causing the built-in soil sensor to misread the amount of dirt in the water.”
Additionally, as reported by the Wall Street Journal, many Whirlpool dishwashers have a “TargetClean” setting equipped with sensors to determine whether food remains on dishes; as many as 40 focused spray jets are set to attack baked-on food. Skip that step and your dishes won’t wind up as clean.
And that’s just how water functions in your appliance. When it comes to detergent, the WSJ reports, “Cascade, made by Procter & Gamble Co., warns against pre-washing, except for removing large pieces of food. Enzymes in Cascade detergent are designed to attach themselves to food particles. Without food, the enzymes have nothing to latch on to.”
Pre-rinsing wastes a lot of water (and energy)
Consumer Reports estimates we use 2 to 6 gallons of water per minute we rinse our dishes. Cascade estimates pre-rinsing wastes up to 15 gallons of water per load. With the average household running 215 loads of dishes per year, that’s 3,225 gallons of water per year that could be saved.
According to CNET, dishwashers built before 1994 use 10 gallons or more of water per cycle, while newer models are far more efficient. “In 2013, new standards were put in place that required dishwashers to use…5 gallons per load.” And an Energy Star certified model can use as little as 3 gallons.
Not to mention the energy it takes to heat all those gallons. As CNET reports, “most newer dishwashers have heaters inside that warm up water more efficiently than your water heater. Overall, if it is Energy Star certified, it can use less than half the energy of washing dishes by hand.”
In the words of the National Resource Defense Council, “if you have a dishwasher, put down the sponge.” Experts advise we should scrape large food scraps off our dishes rather than rinsing each one before loading.
Don’t overload the machine (but make sure it’s full)
Of course, getting the best functionality out of your dishwasher is predicated on proper use. All those high-tech sensors and spray jets need adequate space to do their job. After checking your owner’s manual for loading instructions specific to your washer, place cups, glasses, small bowls, and plastic items in the top rack, and plates, serving pieces, and larger bowls in the bottom rack. Make sure cutlery is mixed among the baskets to avoid “nesting.”
Leave space for water and soap to flow properly, but be sure your washer is full enough to merit being run. According to the EPA, “Running the dishwasher only when it’s full can eliminate one load of dishes per week and save the average family nearly 320 gallons of water annually.”
Of course, there are some more delicate items that should never go in the dishwasher. For these, we have little choice but to hand-wash. For everything else, you can safely stop pre-rinsing and let your dishwasher do the work from here on out.
