22 May 2009

How to care for and feed your dishwasher

Thursday's New York Times contains their weekly Home and Garden section. It's always worth the peruse. Always. In that weekly section, there's a recurring column called The Fix, where a Times staffer fields a reader's question.

This week's installment of The Fix was written by Arianne Cohen, and she tackled the question, "Why isn't my dishwasher cleaning my dishes?" Ms. Cohen did a great job with the answer and parts of her column were news to me. Adding to my store of appliance knowledge is something I'm always happy to do and I'm going to excerpt some of her more interesting points here.
“Pre-rinsing dishes is a big mistake,” said John Dries, a mechanical engineer and the owner of Dries Engineering, an appliance design consulting company in Louisville, Ky. “People assume that the dishwasher will perform better if you put in cleaner dishes, and that’s not true. Just scrape. Pre-rinsing with hot water is double bad, because you’re pumping water and electricity down the drain.”

It’s actually triple bad, according to Mike Edwards, a senior dishwasher design engineer at BSH Home Appliances in New Bern, N.C. “Dishwasher detergent aggressively goes after food,” Mr. Edwards said, “and if you don’t have food soil in the unit, it attacks the glasses, and they get cloudy,” a process known as etching that can cause permanent damage.

It’s also important not to use too much detergent, he said.

How much do you need? That depends on how much food soil there is, he said, not how many dishes. “If you have a light load,” he said, “don’t fill the detergent cup all the way.”

Powder detergent is preferable to that in liquid or tablet form, he said, because it leaves dishes cleaner. But store it somewhere dry, not under the sink, where it can absorb moisture and form clumps.
That's an interesting note about pre-rinsing dishes. Who knew that when a detergent doesn't have enough to do, it goes all renegade.
Mr. Dries offered a final tip: stick with the normal cycle. It’s the one consumer organizations conduct all their performance and energy tests on. “Manufacturers know this, so it’s the cycle that the most work went into,” he said.

The pots-and-pans cycle is rarely necessary, except when you have baked-on foods, he said, nor is the heat-dry function.

“A trick you can use is called flash dry,” he added. As soon as the dishwasher shuts off, open the door. “Dishes are at their hottest point and give up water moisture the fastest. Within 5 to 10 minutes, your dishes are going to be completely dry.”
I love this kind of insider information. The bit about all of the engineering of a dishwasher getting poured into the normal cycle is really go to know too. And flash drying, who knew?


  1. I never pre-rinsing dishes, great tip about flash dry must try it tonight!
    have a great weekend Paul!

  2. Hey! You're back from your travels. It's a holiday in the US this weekend in the US this weekend and I need a break. You have a good weekend too Mel!

  3. does flash dry work on plastics? they don't hold heat the same way other materials do...

    There are some high end dishwashers that automatically pop the door open when they're done (i.e. you don't have to remember at the right time). I know some Mieles do this, but I expect they're not the only ones to do it.

  4. Rachele,

    I don't know how well flash drying would work on plastics, but I'd imagine flash drying's effectiveness would depend a lot on what else is around the plastic objects. A plastic cup surrounded by glasses and plates would probably dry more thoroughly than a tray full of plastic cups would.

    We need someone who's willing to do a little experimenting and then report back. Anyone? Anyone?

  5. I've been flash drying for 20 years to save electricity. The plastics usually have a few drops of water left on them so I move them to the countertop or table for an extra few hours of drying. Another benefit is that the plastic tops don't warp from the heat.

  6. Cathy,

    Thanks for weighing in. I'll pass along your findings to Rachele.

  7. THANK YOU Paul! Lots of fesitivies here in Canada's Capital and it is an extra special day as Her Majesty Queen Elizabeth II is also visitng us.


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