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Dec 31, 2008 12:16 PM

Knifes in the dishwasher

I know that this question is likely going to make some people cringe but I have to ask: What's wrong with putting a knife in the dishwasher?

Every string of posts that I read about knives seems to invariably have someone making the comment that you shouldn't put good quality knives in the dishwasher. I am no expert, and I am not looking to argue about it. I am just curious what it does to the knife. I put all mine in the dishwasher although I am careful to align them so that the cutting edge isn't resting against anything that would obviously damage it. Is it the heat from the dishwasher that's the issue? Abrasion from the water? Just the risk of them contacting something else? I am just curious what the problem is?

The few decent knives I have a Henkels, no Japanese steel because I don't need anymore knives - (just a home cook).


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  1. Assuming that you're talking strictly about stainless knives, the main problem is that they tend to get jostled around, which means that the edge can be ruined by contact with hard things (a glass, another knife, etc.). A second problem is that the extremes of moisture and temperature can loosen the handles (not an issue with, eg, Fibrox handles, but the scales on your Henckels might loosen up before they otherwise would. Finally there's the safety issue - I'd sure be nervous reaching into a dishwasher full of razor-sharp blades.

    1 Reply
    1. re: alanbarnes

      You've read the other threads so you know this question, which arises every two months or so, brings out great passions. Alan's answer is pretty reasonable. However, I would add that it is fairly easy to put a knife in the DW in such a way that it won't be harmed by being jostled around.

      I have three Dexter-Russell Sani-safe 4" paring knives that I use practically every day, and nearly every day they go in the DW along with other table silverware. Note that these are designed to be OK in the DW, and are NSF rated. In any case, this has been going on for at least three years, so they have all been through the DW now at least several hundred times, and I use high heat (sanitizing cycle). None of them shows any sign of nicks, stains, excessive dulling, or any other problem. I do the same with larger Sani-safe knives I have--they go in the top rack. No problem with them either, but they go through the process less frequently.

      So IMO it's OK depending on the particular knife. I would not DW a wooden handled knife. That's a whole different thing.

    2. how does a knife get so dirty that it takes more than a wipe with a damp cloth to clean????

      3 Replies
      1. re: ScubaSteve

        >> how does a knife get so dirty that it takes more than a wipe with a damp cloth to clean???? <<

        When cutting raw chicken. When mincing garlic (it's sticky stuff). When dicing smoked salmon (that fishy oil gets everywhere). When grabbed with a hand that has been mixing vegetables with olive oil. When dropped on the floor into a pile of cat fur and dust bunnies.

        Knowing what I do about where my knives have been, I'd be very nervous eating food prepared by someone who doesn't use soap and hot water on their knives.

        Me, I put my knives in the dishwasher. I deliberately don't own super-fine knives because I don't want to hand wash them.


        1. re: AnneInMpls

          Anne! I was thinking the same thing about cutting chicken! I do put my knives in the dishwasher, but I also think they dull quickly and suspect that the dishwasher has something to do with it.


          1. re: AnneInMpls

            i would still just give that knife a quick rinse and a pass with a soapy sponge and move on.

        2. I have to agree with scuba - the question is WHY do you want to put your knives in the dw? If you're convinced that knives have to be sanitized at high temperatures, I guess we would never see you at sushiyas or the great majority of commercial restaurants and kitchens where chefs simply wipe their knives after each use. I wipe mine after each use, then I wash mine at the end of the meal, by hand, dry, hone, and put them away. I do not cut raw meat with the same knife I use on other items.

          Edges are temperamental - if you've worked on a set of stones, building up an edge, you know how sharp you can get it, and how quickly, with even a little use, the super sharpness goes away. The only way to maintain that is to hone - hone when you take it out to use, hone before you put it up. The edge rolls over, warps - even sitting by itself in the knife block, temperature and humidity differentials can affect the edge. That's why you hone in and out.

          If you're happy putting your knives in the DW, and you notice little difference in use or wear, go right ahead - they're your knives. But I can think of no reason to do so - sanitation or otherwise.

          15 Replies
          1. re: applehome

            Very simple. I use and continuously re-use a lot of pieces of small equipment in my cooking--knives, spatulas, stirring spoons, cutting boards, etc etc.. I have a set pattern of how I cycle them, ALL OF THEM, through the work flow. I use them, then I DW them, then they get put back in their storage places, then they get taken out to be used once again, and so the cycle continues. For me, I want the simplicity of a single cycle for everything--I don't want special deviations for anything. I also don't especially enjoy hand washing anything. For these reasons, years ago, I converted everything I use to be DW safe, and mostly NSF. I use high temp spatulas, for example, not wood spoons--in fact, I have expunged wood from my working tool set entirely. That way I don't need to take my attention off my cooking (mind you, I obviously wipe knives and use them for various tasks as the day goes along, but in the end they go in the DW and are put back in their storage places). This cooking style works for me. And the important bit relative to the OP is that my knives work in a totally satisfactory way for me, and I don't need to baby them or treat them in a special way. Personally, I am continuously amazed by the posts, here and on other food boards, where folks endlessly obsess over knives. It's fine to take care of one's equipment, and have good equipment, but to me they are not objects of religious devotion, which it the way I see some others treating them, but simply tools to do a job. I too have good, though not highbrow, equipment and I take care of it, as my results show. My edges are plenty sharp. But primarily I just want to get the job done and enjoy the results on the table--the grade of steel used for the knife, endless honing, the price paid, where it was made, and all the rest of it is of little interest to me, as long as it performs its function well. Others can do what floats their boat. The knives I have chosen, and the way I use, clean, and care for them, do the job just fine for me.

                1. re: johnb

                  I think that works for you (obviously). I grew up valuing tools - just one of those things my father taught us and we've passed on to our kids. You don't throw your tools around in the garage or the kitchen. Tools are to be used, but they're to be taken care of, so you can keep using them. It's just a different value - not better or worse.

                  I do feel that most people, given the chance, will appreciate a fine tool, especially a great knife. Whether they'll appreciate it enough to pay for it and take care of it in the way it needs to be taken care of - well - that's up to each and every one of us. But every time I hear someone complaining about crying when dicing an onion, or thinking that it takes effort to cut things, I know they have a bad tool in their hands, whether it's just a badly made device or one that simply hasn't been taken care of. And I know for a fact that I don't want any raw meat - whether sashimi or carpaccio, cut by the standard western style knife in a kitchen where there is little concern for sharpness. The cell damage from a dull knife will affect the texture and the taste, and will also bring about the immediate start of spoilage.

                  There are many reasons to want real sharpness in your knives - and if you are concerned about that, then you can only achieve it with the right tool and the right care. Using dishwashers is not the right care for the right tool.

                  1. re: applehome

                    Thanks for the feedback. Like I said originally, I didn't know if there was some thing about it that damaged a knife or the steel or if the concern was about the edge. I do put my knife on the top rack, separate and away from other items. I agree that putting it in the cutlery basket would be asking for damage and likely an accidental cut someday.
                    I do often hand wash it, particularly when I need to use it again (I don't have many decent knives) but sometimes it just goes into the dishwasher because I am tired or lazy or have to get the kids in bed or any of the other things that seem to eat into life these days. I am glad to hear that it doesn't look like I am doing permanent damage. I do steel my knives before each use and sharpen regularly using a Lasky sharpener (not trying to get into a sharpening debate) so it remains fairly keen despite my dishwasher abuse. I know I could treat them better which is one of the reasons that I stick with what I have instead of shelling out for a nice Japanese steel blade.

                    1. re: applehome


                      Where did you get the idea I don't value tools, as you implied? I certainly do, and I do appreciate fine tools. I take care of my knives, I don't "throw them around," and believe it or not your "values" are neither different from, nor superior to, mine. My knives are sharp and they work just fine. I have no problem dicing onions with my knives--I dice onions all the time, without effort. My knives are not dull--they are quite sharp thank you. Washing my knives in the DW, as I do it, does not dull them, or have any other deleterious impact. Just because you have been saying to yourself all along that it does, that doesn't make it so. You are just flat wrong about that. Of course that doesn't apply to all knives--there are many that would be harmed in a DW, but one can easily acquire good knives that will do fine in the DW if one wishes to do so.

                      And by the way, that is an interesting assertion you have made about "dull western style knives" damaging the taste and texture," and "bringing about the immediate start of spoilage." Apparently you are a Japanese knife freak. But beyond that, what credible scientific data do you have to back up that claim? I'm sure our knife maker friends in Germany and France would love to hear more.

                      1. re: johnb

                        My husband's a chef, and he puts his work knives in the home DW. He doesn't at work, because basically, he doesn't want them to walk away. Of course, he's not the one cleaning up after himself, either.

                        If you're reasonably careful, the DW isn't going to hurt them.

                        1. re: johnb

                          Here we go again - I guess I could point to one of my posts from about 7 years ago. But then again, it's probably time to present the sharp knife facts from scratch. I say facts, because the sharpness and quality of the steel and manufacture, and how to best take care of them, are facts. The opinions have to do with whether or not the best knives are worth the cost and time to maintain them. As I have been saying, everyone needs to come to an understanding, for themselves, where they want to venture to in the knife world. Maybe restaurant quality, fibrox handled, stamped Victorinox/Forschner or Dexter/Russell knives are good enough to turn out a meal - maybe there's more to it. But you'll never learn about anything better, if you simply insist that what you have is plenty good enough.

                          Let me ask this - how would you know what is sharpest? Not "sharp enough", mind you, which can be subjective and entirely based on your own experience, but when working with many knives - can you tell when one is sharper than the other, even beyond what is seemingly functional? Are you so sure that factory manufactured German and French steel is as good or better, that is, can be made as sharp and will hold the edge as long, as any other steel? When you dice an onion, and you do it well, how can you be sure that there is nothing better, no steel that would actually lessen your effort even from what you think is all you need?

                          There are a whole slew of knife enthusiast sites that deal with entirely new generations of steel, powdered alloys and extreme tempering techniques, that achieve the highest hardness factors. There are big differences in the western and Japanese steel traditions, dating back centuries. Bifurcated blades, long since a tradition of Japanese swordmakers, allow unusually hard and brittle core materials to be useful, by cladding them with softer steel. Today's powdered steels can only be used by these techniques.

                          Here is a clip from Murray Carter, an American who lived and trained in Japan, as a bladesmith, for many years, He is a 17th Generation Yoshimoto Bladesmith and Certified Master Bladesmith. He generously gave me permission to use this clip. It is from his Advanced Knife Sharpening DVD. I highly recommend his hand-forged knives, as well as his knife sharpening DVD's (both beginner and advanced).


                          Here is his site:

                          There are numerous other sites where knife enthusiasts discuss pros and cons of everything from the steel to certain sharpening techniques. You can do a search here and you'll find more material than you could imagine. I'll list a couple of favorites here, but there are many, many more:




                          1. re: applehome

                            Okay, but why don't YOU tell us why one shouldn't put a knife in a DW? What happens to it? I believe that's the question.

                            1. re: c oliver

                              I've already stated this:

                              "The edge rolls over, warps - even sitting by itself in the knife block, temperature and humidity differentials can affect the edge. That's why you hone in and out."

                              Obviously, the range of temp/humidity is much greater in a DW and so the edge will be affected more. The point is that sharp knives have to be constantly honed to stay sharp - if you're doing this coming out of the DW, you're certainly doing what you can to keep it sharp - but why did you bother to put it in the DW if you're going to take the time to handle it separately anyway - what was the _benefit_ of the DW?

                              I would assume that people who put their knives in the DW are just taking them out with the rest of the utensils and putting them up in the block or drawer. This is what is keeping that knife from being as sharp as it could be.

                            2. re: applehome

                              Thank you for your extensive post. I'm well aware there are many knife enthusiast sites, and many knife enthusiast threads/comments here on CH and on other food boards (e.g. CH has nothing on eGullet in this regard). I alluded to that in my earlier reply, and added that I was amazed by the obsession exhibited by some. I think you have demonstrated clearly that this truly is an obsession of yours and is shared by others. Fine, be obsessed if you want. But you also have to realize that, even though you may have a high level of interest in the subject of knives, that doesn't mean that your approach to owning and caring for them is any "better" than that of others less obsessed. I will give an analogy. There are those who are automobile obsessed, believe Ferrari's are the best thing out there, and if they own one spend a great deal of time keeping it perfectly shined and detailed. That's fine, but a Honda will get a normal person from point A to B just as well, maybe even better. And it is inappropriate and wrong-headed to criticize the Honda owner for not spending hours polishing his Honda. My point is that to me and I think most normal people a good knife is fine, but it is not necessary to obsess over it and spend inordinate amounts of time and energy keeping its condition up to an standard far beyond what is needed to do the job it is meant to do. Life is too short. If you want to do that out of interest, love, whatever, I have no quibble with that, but don't criticize me if I choose to use my time and energy in other pursuits.

                          2. re: applehome

                            >>Using dishwashers is not the right care for the right tool.<<

                            Why? I was just considering why I've been handwashing knives and then this came up. I'm sure it dates back to when all my knives had wood handles but most of those are gone now. Like another poster, I'd be inclined to place them on the top rack lying flat, etc. So WHY is putting knives in dishwashers not the right care?

                            1. re: applehome

                              It sounds like johnb values his tools very much. He has made choice to buy tools that are DW-safe and he treats his tools with care and he just took the time to explain very clearly. I have no doubt that if I went to his house I would find a set of well-cared for kitchen tools and very sharp knives.

                              I'm not convinced that my hand-washed knives are any better card for, just more obsessed over.

                              1. re: taos

                                See - this is just MHO, not a fact, but saying that somebody values their tools (knives) because they have bought DW-safe ones, is a bit like saying that I'm valuing or respecting cars, by buying an easily maintained, cheap car. That's certainly two aspects of a car - easy maintenance and cheap. But are these the aspects most people associate with reverence for cars? There are certainly some ways in which Hondas are better than Ferraris - and for the great majority of people, the Honda is indeed a better fit to their daily needs. Nevertheless, while I do, in fact, have a reverence for Hondas and Toyotas for their reliability, if I were asked what cars I truly revered, I'd probably point more to a Ferrari or Porsche, because what reverence really is referring to, is performance.

                                Back to knives. I'd expect someone to show reverence for knives by buying and maintaining a great knife - not by buying something that allows them to be, let's say, less directly involved with their maintenance.

                                1. re: applehome

                                  I didn't say he valued his knives because he bought dishwasher safe knives. I said, or meant to say, that it was clear from his post that he valued his tools and cared for them well, despite the fact that they were dishwasher-safe.

                                  As for reverence, that's a subject for a different debate. Suffice to say, for some people it has nothing to do with performance or even with inanimate objects at all.

                        2. To the dismay of some folks on this board, I throw my knives (even my Globas) in the dw, sharp side up and placed so they don't come into contact w/anything else....