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As we were looking for laundry detergent yesterday, I noted that my wife was quite swayed by brand reputation/impressions than price. She stated that she didn't think one type of detergent really removed stains. I asked if she'd ever consciously been aware of this and noticed, and she said "No."

It's not hard to find some other references like this, such as About's list of top detergents HERE:

These laundry detergents are some of the most effective and efficient available to keep your clothing clean.

  • Tide Laundry Detergent
  • Gain Joyful Expressions Laundry Detergent
  • Purex Complete 3 in 1
  • Method Laundry Detergent
  • Cheer TrueFit Laundry Detergent

They don't really describe anything about how they came to these conclusions, however.


Question: Is there available evidence in which someone has attempted a controlled experiment evaluating different detergents for their ability to remove (make un-detectable by sight, touch, or smell) stains/dirt? Perhaps in addition, some site that has compared soil-removing ability with price?


Edit: Freebie for an answerer... Consumer Reports apparently tested 50 detergents HERE. The abstract indicates that Tide, indeed, was the best, but that there was a law of diminishing returns at play. Anyone with a subscription who can post some key quotes?

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Nice question, I am convinced there is no difference except perfume. I mean, how many ways are there to make a laundry detergent? –  Sklivvz Jul 24 '11 at 16:23
    
@Slivvz: also, just looked at this, but detergents are much like other soaps and diapers: an illusion of choice. I work in an industry that has made me incredibly aware of the fact that Proctor & Gamble and Kimberly Clark own an enormous share of the personal care product market. In fact, I just checked and Proctor & Gamble makes: Tide, Cheer, Bold, and Gain (LINK). I'm still interested in formula variations -- P&G might make some deliberately not as good as others? –  Hendy Jul 24 '11 at 17:10
    
Sure, there's also another claim, by my uncle actually, that most of the cost of detergents is the box (i.e. the container and the marketing). The product itself is basically almost free. –  Sklivvz Jul 24 '11 at 17:12
    
@Slivvz: probably not far from the truth. I've heard some advertising/box-to-product cost ratios before from my company and was asssttouunded. Sometimes the R&D is done on something quite new and it takes the marketers a lot longer to figure out what to sell it in. You should post that claim as a question! –  Hendy Jul 24 '11 at 17:17
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anecdote: from textiles classes I've read about, it has been shown that for "most" fabrics, merely washing in highly-agitated water will have a nearly=identical effect as will using any form of soap –  warren Jul 25 '11 at 14:42

1 Answer 1

up vote 13 down vote accepted

Yes, there's a difference. I found a test report executed by a producer of standard stains. They're showing off their stain set against ther competitors, and to prove their relevance they test with 10 different detergents. While unnamed, the results do differ significantly.

(It's also a telltale sign that there are multiple R&D labs that provide standard stains to detergent producers; they must spend quite a lot on R&D if they can support multiple suppliers for such a specialized product line)

The test method used prepared controlled samples of cotton cloth, stained with the following materials (chart from page 3 of linked report):

stain types

To determine how clean the clothes were after washing, they used reflectivness, as explained here (from page 6):

The highest reflection value after the wash. This indicates how clean the testmaterial, washed with the best performing detergent, is. The most cotton reflects ca. 87-90% when unsoiled. The more this value reaches this point the closer it gets to completely clean. When a testmaterial is cleaned completely by one or more of the detergents there is no room for differentiation left, this is therefore unwanted.

Results are presented visually in a bar chart of stain type vs. delta-R (change in reflectivity from stained cloth to cleaned cloth) for all detergents. A sample chart for the wine stained cloths (there is one for each stain type) is shown here:

wine stain chart

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Thanks! Can you include some citations from the document please? I did take a look but I didn't see exactly where these significant differences are shown :-) –  Sklivvz Jul 26 '11 at 15:30
    
Holy stained shirts batman -- that report is amaaazing. –  Hendy Jul 26 '11 at 15:42
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@hen it's the iDetergent :-) –  Sklivvz Jul 26 '11 at 16:07
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@Hendy: thanks for the quotation work. If you thought your laundry was a chore, imagine the amount of washing they'd had to do. –  MSalters Jul 28 '11 at 9:26
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TIL that "standard stains" is a product. –  Larry OBrien Dec 16 '12 at 19:10

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