"Kitchen knives get dull in a dishwasher." Myth or fact?

Assuming that they don't rub against anything in a dishwasher.


So I guess things to consider could include:

- abrasives

- repeated thermal stress

These are probably negligible on the scale of kitchen knives. Anything else to consider?

8 Answers

    Lv 5
    1 decade ago
    Favorite Answer

    The main reason knives get dull when they are run through the dishwasher is because they get banged into other silverware, plates, and other things in the dishwasher. This causes the edge of the blade to bend and develop nicks and scratches.

    If you look closely at a dull knife you can see that the edge of it is no longer forming a perfect point. These bends and wrinkles are what causes knives to get dull so quickly and is one of the reasons you should use a honing steel before using them everything.

    While these dents and bends are caused by normal use, running knives through the dishwasher not only speeds up the process but also creates ones that are much worse than normal. Often times this makes the honing steel less effective until you sharpen the knives.

    Dishwasher Affects on Knife Handles

    While the dulling of knives in the dishwasher can be counteracted by sharpening them more often, the dishwasher also has another adverse effect on knives. The chemicals contained in most dishwasher detergents are very harsh and can react with knives and their handles.

    These chemicals can cause the knife handle to discolor or even become pockmarked, especially the synthetic handles common on many knives.

    The knife blades themselves can also be affected by the dishwasher detergent chemicals. The chemicals can stain and discolor the knife blades or even corrode them.

    Proper Knife Cleaning

    After using, clean your knives promptly in the sink, by hand, without the use of harsh chemicals. Dry them and put them away right after you wash them. This will ensure that your knives stay sharper between uses and won't discolor or corrode.

  • 7 years ago

    A standard question people ask us at markets where we sell our knives is this very one: Can I put it in the dishwasher? We say no for the same reasons as Quahog said. You'd be surprised just how quickly a fine fine edge will roll over if it even brushes against other tools, as could easily happen during loading, unloading or during washing in a dishwasher. Same is true for store knives loose in a tool drawer instead of a knife block. This is not about detergents containing abrasives that will dull an edge, though dishwasher detergents usually contain caustic chemicals to do their job and the high-end stainless steel used in the best modern knives is not truly stainless; a dishwasher can mar the finish.

    Source(s): northarmknives.com
  • maki
    Lv 4
    4 years ago

    Knives In The Dishwasher

  • Anonymous
    6 years ago

    This Site Might Help You.


    "Kitchen knives get dull in a dishwasher." Myth or fact?

    Assuming that they don't rub against anything in a dishwasher.

    Source(s): quot kitchen knives dull dishwasher quot myth fact: https://biturl.im/eFRYA
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  • 1 decade ago

    The dishwasher's effect should be negligible on your kitchen knives because it is only spraying hot water on the knives. I highly doubt the jets in the dishwasher would be powerful enough to dull your knives more then your cutting food with it.

  • Anonymous
    6 years ago

    What kind of dishwasher was this person using that banged items together so harshly that dents and bends were caused? I am going to chalk this us as an old wives tail....

  • Dr. R
    Lv 7
    1 decade ago

    This would require there to be an abrasive powder in dishwasher detergent (like pumice in ajax) or sand in the food washed off and redistributed by the jets. Neither is generally the case.

  • 1 decade ago


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