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Putting pots and pans in the dishwasher- why not?

I don't understand why people get so up in arms about putting pots and pans in the dishwasher. I wouldn't put anything coated in a non-stick coating in the dishwasher, as it could possibly wear the coating down a little quicker. Or anything wooden, as there is the possibility it could warp, but why are people so freaked out about putting their knives and pots/pans in the dishwasher?

Please help me understand, am I missing something?

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  1. Usually, it's because of the handles if they are plastic. I'm with you tho, if it's not nonstick, wood, or (dishwasher safe) plastic, I don't have any issue putting it in.

    1. Don't know if this is true, but I was under the impression that putting knives in the dishwasher dulls the blade more quickly.

      1. I don't put knives in the washer because I don't want to damage the blades or my hands. I generally don't put pots/pans in because they don't fit well and my dishwasher doesn't do a good job with cooked on food. Plus, the pots on the bottom rack interfere with the sprayer so the glasses on the top rack don't get as clean. I also kind of like washing pots and pans - I like to see the shiny metal emerge from beneath a layer of gunk :)

        7 Replies
        1. re: mpjmph

          These are all good points. The pots and pans you shouldn't put in the dishwasher are the anodized aluminum (or dark exterior) pots and pans. They are electro-hardened and the dishwasher will leach out this property and damage your pans.

          1. re: igorm

            Regular aluminum can also react with the (usually) very alkaline dishwasher detergents, but for my cheap aluminum pots I don't care much. Cast iron obviously can react in the washer. I have no problems putting stainless or enameled pots and pans in the dishwasher.

            My dishwasher has a center and top sprayer so blocking the water flow isn't an issue.

            1. re: kmcarr

              Kmcarr and others, with enameled cast iron, aren't the rims often bare cast iron? I often wondered about that (don't have enameled CI myself but hoping to try one soon) -- why do they leave the rims bare and doesn't that lead to rust, esp in the DW?

              1. re: iyc_nyc

                Usually the rim is black matte enamel, not bare cast iron.

                1. re: Chemicalkinetics

                  Ahh. Someone at WS insisted it was bare cast iron! (LC and Staub)

                  1. re: Chemicalkinetics

                    CK: No, you may have some with black enamel rims, but quite a few of mine are bare naked ladies. My sink and counter have the rusty ring stains to prove it. The Chinese DOs I saw this past weekend at World Market ($49--a GREAT deal) definitely were bare-rimmed.

                    iyc: I think the reason is abrasion and fracture resistance. If all the mating surfaces (especially the narrow ones) of lids and rims were enameled, you would have some chipping over time. Now, chipping on BOTTOM rims is OK, because the chips aren't going into your food. Chips going into the food are not good. Only recently did LC change their enamel formula to eliminate cadmium; I'm not so sure every other manufacturer is a scrupulous.

            2. re: mpjmph

              I'm so with you on that. I love to handwash my pans and skillets. Dishes, glassware and flatware - nah, not the same satisfaction. Anyone can wash those, however - no one washes my cookware.

              Lame, so lame, I know!

            3. Dunno. I put everything that fits
              (except my knives, and cast iron) in the dishwasher, and none of it has ever seemed any the worse for wear. And my wok. It doesn't fit, but even it it did I'd clean it by hand.

              1. No way I'd ever put my knives in the dishwasher -- they knock against everything else in the dishwasher during the cycle and it wrecks the edges.

                I put everything that fits (see below for exceptions) in the dishwasher -- nonstick, stainless, glass baking pans...the whole works.

                Everything comes out fine with no damage from the heat (I never, ever run the dry cycle -- I just open the door a crack and let the hot water evaporate on its own -- take all of about 10 minutes).

                Crystal and sterling are the only other things I never put in the dishwasher.

                1. If there's room I put my DW-safe pots and pans in. I have some hard-anodized Calphalon that shouldn't be put in. I don't know that it ruins them but one looks awful when someone did that. Any knives that don't have wood handles go in. Usually I handwash all those items simply cause I use them more often than I run the DW.

                  4 Replies
                  1. re: c oliver

                    ah, yes, the Calphalon. When I grow up, I'm gonna buy me some of those! But yeah, they go all nasty in the dishwasher -- my nieces and nephews put my sister-in-law's Calphalon in the dishwasher, and while I don't think it hurt it any, the outsides were all caked with salt deposits down in those tiny little grooves, and they looked like they'd been through a war.

                    1. re: sunshine842

                      "the outsides were all caked with salt deposits down in those tiny little grooves"

                      Part of the anodized aluminum was destoryed just like igorm said.

                      1. re: Chemicalkinetics

                        she's still using them, so obviously it didn't cause any major longterm damage...but they aren't very pretty any more.

                        1. re: sunshine842


                          Agree. The real anodized surface is usually not that thin, but the outest layer is the black/grey layer, so only the very first layer was ruined, but the cooking performance should be the same.

                  2. Knives bounce around and rattle against each other -- it's not good for the blades, if you actually have sharp knives. Butter knives and cheap, disposable serrated knives... I don't care. Some knives are also made out of materials that don't do so well with frequent harsh detergents, as well as having wooden handles.

                    I don't usually put pots and pans in the dishwasher because they take up so much space and can block the jets from spraying water around as much if they are too large. Also, (1) if they don't have anything baked onto them, I can easily rinse them by hand, and (2) if they do have something baked onto them, the dishwasher usually doesn't get it off completely, so I end up hand-washing anyway, either pre or post dishwasher.

                    I speak here of cheaper pots/pans. In general, I don't put anything super-expensive in the dishwasher, whether my copper pots, my expensive knives, or wedding china (even though the latter is theoretically dishwasher-safe... a few years back, we put some coffee mugs from our set in, and the outer finish cracked).

                    I've never ruined anything by handwashing. I have ruined a few things in the dishwasher, or at least increased wear. To me, it's kind of like your "delicates" in the laundry that you take to the cleaner. There are some things that you just shouldn't put in the washing machine/dryer, because it's a harsher environment, and you don't want to risk ruining things.

                    1. Well, actually a lot of cookware can go into dishwashers, but it is not the optimal method for many.

                      For example, it is not good to put aluminum (anodized or not) cookware and copper cookware in dishwashers because they will change color. You cannot put carbon steel or cast iron cookware in dishwasher because that will ruin the seasoning surface and seasoning surface can take weeks to years to build up. I assume you have never had cast iron or carbon steel cookware then.

                      Putting knives in dishwashers is also a poor idea. There are many reasons. If the knives are made of carbon steel, you will rust the knives. Even if the knives are made of stainless steel, not all stainless steels are equally the same. Some stainless steel knives will discolor in dishwashers. Knives can get dull in a dishwasher for two reasons. First, knives get knocked around in a dishwasher. Second, dishwasher detergents are more aggressive than the hand dishwashing liquids. Now, if we are talking about those factory >20o edge angle, it is probably not a huge deal to put these knives in a dishwasher because they are not that sharpe to begin with. However, I often spent hours (not a typo) reprofiling and sharpening my knives on waterstones. These edges are finer than the factory edges. In one simple move, 10+ personally customized knife edges can be destoryed in a dishwasher. It is tough to put a monetary value, but tens of hours of hard works are thrown away.

                      1. I don't put in non-stick or cast iron, otherwise, all pots and pans go in. Twice, if necessary. I don't put in my 'good knives' as it would definitely warp the wood - all the other knives go into the DW.

                        1 Reply
                        1. re: JerryMe

                          Jerry, what do you mean by 'twice, if necessary' -- do you mean that sometimes you need to run two cycles to get your pans clean?

                        2. I have a SIL that puts her Chicago Cutlery (I know, it's not expensive, but it's not terrible) into the dishwasher. She started to do the same at our house once and I told her we wash it by hand. She thought the reason we don't is because of the wooden handles. She said if she had 'new' knives like ours she wouldn't put them into the dishwasher either. Then I told her they were the same age as hers (my mother gave them to us at the same time). Her knives are all dull and the handles faded. The faded wood is not a big deal, the dull blades are. Not only do they bounce around and dull the blades, the harsh detergent isn't good for the blades either.

                          We generally don't put pots and pans into the dw mostly because they are not hard to wash by hand, take up too much space in the dw and deflect the spray, as others have noted.

                          3 Replies
                          1. re: John E.

                            'Then I told her they were the same age as hers (my mother gave them to us at the same time).'

                            Ouch. That hurts. You could have omitted that part out. :)

                          2. A lot of what has been posted is all true, so I will give you some additional tidbits to think about before you put your pots and knives in the dishwasher:

                            - Even stainless steel flatware knives have been known to rust in the dishwasher. How is that possible? Probably because dishwashers are left to sit full all night after washing and get emptied in the morning, at least in my house. That is a moist environment in there and leaving just washed flatware, let alone good knives and, heaven forbid, wood handles in there for hours will ruin quite a bit. The dishwasher is probably bad enough, but the overnight sit is nearly fatal for some things.

                            - I have a lot of enameled cast iron, mostly LC, some Staub, some others. Invariably, the knobs on the handles are screw-ons. Even if the pot has no chips and a black matte finish on its edge, the screws that hold the lid handles eventually rust. The culprit? Probably the moist dishwasher environment when the lid is left to sit after a load has run for hour. If you are going to put it in the DW, which I would recommend not doing, remove it promptly and dry it.

                            - Utensils rust, and sometimes their handles come unglued too. Heat and hot water from the DW is clearly to blame.

                            - Any kind of black rubbery material that is used on utensils eventually becomes a gummy mess that blackens the user's hand. Think OXO tongs, potato peelers etc. They get replaced quite a bit around here.

                            Yeah, I put a lot of stuff in there too, but no good stuff or expensive stuff. The replacement cost is not worth the few minutes it takes to handwash and dry. And please, remove the stuff from the DW promptly when the was cycle is done.

                            3 Replies
                            1. re: RGC1982

                              "Even stainless steel flatware knives have been known to rust in the dishwasher"

                              Actually one more reason. For those very nice 18/10 stainless steel or 18/8 stainless steel flatware, the blades of the knives are not made of 18/10 or 18/0, so the blades are much easier to rust. The reason is taht 18/10 and 18/8 are not great steels for knives. Here is something to try. Get a refrigerator magnet and put it next to the forks and spoons, if your stainless steel flatware are 18/10 or 18/8, you will feel no or very faint magnetic pull. Now, try the knife blades, and you will feel a stronger attraction.

                              1. re: Chemicalkinetics

                                The only thing I WILL NOT put in the d/w is my treasured cast iron and anything crystal, silver or hand painted. Everything else goes in, knives included, although in their own compartment or the top rack for the big ones. You have to sharpen them anyway and the heat dry dries the handles fast enough. I don't own Calphalon but I know more than one person who does and puts it in and it's fine--cookware, but NOT bake ware because of an air layer or something. I hate washing dishes and the less I have to do, the better.

                                1. re: Whosyerkitty


                                  Good points. I don't mean flatware and cookware should never be put in a dishwasher. I was trying to explain why different people take different positions on these matters.

                                  The orignal post was inqurying the reasons why some people are "up in arms" about using dishwasher for knives and cookwares. When reading it between the lines, I felt the original poster has tried to be helpful and put other people's knives and cookwares in dishwashers and was told not to do so. It is one thing to slightly dull your own knives and have to sharpen them later. It is another thing to dull the host's knives and make him/her to sharpen the knives later.

                                  I cannot remember what these actions are called. "Unhelpfully helpful" or "Helpfully unhelpful".