Should you pre-rinse your dishes before loading the dishwasher?

By Lori Bongiorno
More from The Conscious Consumer blog

(Photo: Getty Images)
(Photo: Getty Images)

Experts unanimously agree that you should NOT pre-rinse your dishes before loading the dishwasher.

Why not? Because your dishes will not get any cleaner if you rinse them before loading your dishwasher. Pre-rinsing is therefore a complete waste of time, water, energy, and money. And, in some cases, it can actually harm your glassware.

Still not convinced? Here are the details.

Dishes will not get any cleaner if you pre-rinse them.

Modern dishwashers and detergents have come a long way in the past couple of decades. "You will not improve your wash performance one bit by pre-rinsing," says John Dries, a mechanical engineer and owner of Dries Engineering, an appliance design consulting company. He points out that heavily soiled dishes are used in pre-market "wash tests," not pre-rinsed dishes.

In most cases, all you need to do is scrape your plates over a trashcan to get rid of bones or chunks of food. One caveat: It's a good idea to pre-soak pans or dishes that have something really burned on them. Pre-rinsing doesn't help in this situation.

Use the dishwasher's rinse cycle if you're not going to run your dishwasher immediately and are worried about the smell of sour food.

How about older dishwashers? "People with any age dishwasher can feel comfortable knowing they don't need to pre-wash dishes before washing them in the dishwasher," says Jill Notini, a spokesperson for the Association of Home Appliance Manufacturers.

Pre-rinsing is a complete waste of time, water, energy, and money.

With pre-rinsing you're essentially washing your dishes twice. Rinsing your dishes while letting the water run can waste gallons of water. Consider this: An energy-efficient dishwasher uses up to 5 gallons of water to wash an entire load of dishes. Washing dishes by hand while letting the water run can use up to 27 gallons.

The same is true for electricity if you pre-rinse with warm or hot water. "You use more electricity rinsing dishes off in the sink than the dishwasher uses to wash the whole load," says Mike Edwards, a senior design engineer at Bosch Home Appliances.

Instead of pre-rinsing the dishes, spend your time on something that will make a difference: Loading the dishwasher correctly.

Experts say a properly loaded dishwasher can significantly impact how clean your dishes turn out. "The biggest impediment in washing is due to poor loading," says Edwards. Get tips from Consumer Reports and a video from Bosch.

Rinsing dishes before loading the dishwasher can do more harm than good.

Today's advanced detergents are designed to attack food particles left on dishes. "If there isn't food soil, they tend to attack glasses," says Edwards. "Some glasses are more susceptible to this kind of attacking than others."

The detergent etches small pits in glasses that you can't see with the naked eye, but the glass appears cloudy, according to Edwards. The process is called "etching" and causes permanent damage.

This is different than temporary hard water stains, which can also result in the cloudy appearance of glassware. Find out how to tell the difference.

"Your detergent amount needs to be based on the amount of food soil in the dishwasher," says Edwards who also points out that those who have soft water should use less detergent than those who have hard water.


Environmental journalist Lori Bongiorno shares green-living tips and product reviews with Yahoo! Green's users. Send Lori a question or suggestion for potential use in a future column. Her book, Green Greener Greenest: A Practical Guide to Making Eco-smart Choices a Part of Your Life is available on Yahoo! Shopping and Amazon.com.


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