Save me some work

October 25, 2005 10:32 AM

Help me to deflect criticisms of my dishwasher usage. What sorts of dishes is it safe to wash in the dishwasher, and which ones are bad?

Bonus points for authoritative answers, extra for peer-reviewed (although that's an AIR award waiting to happen). The class of story that's least useful, although might still help, is "My mom told me..." since that's what I'm trying to deflect.

posted by ChrisR to home & garden (24 comments total)

What do you mean by what sort of dishes? The material they are made from, like acrylic or ceramic? The type of dish, like plates, bowls, pots, pans?
posted by pmbuko at 10:38 AM on October 25, 2005

Plus it depends if you mean bad because it's bad for the dish, or bad because it's bad for the dishwasher, or bad because it's bad for the system of using a dishwasher to do dishes.

So, in the first group are certain plastics that crack with too much heat, wooden handles knives, wood generally and very very delicate glassware that might get bumped into and destroyed. In the second group are things with little pieces that might fly off and get caught in the mechanism, anything too big that keeps the sprayers from spinning and anythign with huge chuncks of food on it that gets stuck in the filter. Also crap put in incorrectly, like bowls or cups which are bowl side up and fill with water, I never think they're quite clean. Third group is big pans that keep you from loading the dishwasher fully and make you do more loads of dishes, the aforementioned big chunks of food [that can break up abd become food that is stuck onto other places where it didn't even come from] and things that are just unwieldy in some way and should be washed by hand.
posted by jessamyn at 10:43 AM on October 25, 2005

Keep the beautiful japanese knives and laminated cutting boards out, just wash everything else until it falls apart and then get ones that work in the dishwasher.
posted by StickyCarpet at 10:46 AM on October 25, 2005

I started putting my disposable paper plates in the dishwasher and it works great if they're the kind with a shiny plastic resin coating them.

I also put any kind of pot or pan in the dishwasher, even if it's got 2 or 3 layers of burnt sauce and cheese or whathaveyou. If it doesn't come clean the first time, just leave it in there for the next load and the next, it will be clean eventually. Labor saving devices mean we shouldn't do any labor. I am constantly amazed by those who pre-wash their stuff before putting it in the dishwasher.
posted by blue_beetle at 10:46 AM on October 25, 2005

Oh, and never put a wooden bread board in the dishwasher. And never use it to cut anything that isn't bread. It's a bread board, not a cutting board.
posted by blue_beetle at 10:49 AM on October 25, 2005

My pots and pans have a nonstick surface (Anolon) and the manufacturer says they need to be hand-washed. Other than those, pretty much everything else I use goes in and gets very clean, with no pre-washing unless I've really, trully gunked something up (rare).

I do make sure to avoid purchasing non-dishwasher-safe items, esp cheap plastics.
posted by skyboy at 10:50 AM on October 25, 2005

Oh, and never put a wooden bread board in the dishwasher.

Why not?
posted by tristeza at 11:29 AM on October 25, 2005

No knives, as detergents can dull them, nothing wooden that will dry and crack, and nothing with rice, since that tends to get thrown around and stuck on everything else.

I've wondered if I can put my good pots in there, aluminum, some with Teflon.
posted by MrMoonPie at 11:31 AM on October 25, 2005

Oh, and no cast iron, as you don't want the detergent to dissolve the embedded oils (actually, I think that's the same reason you shouldn't put wooden items in).
posted by MrMoonPie at 11:33 AM on October 25, 2005

Some unfinished metal items can't be washed in the dishwasher (unfinished aluminum especially), as they'll corrode. If you have a Kitchen Aid mixer, for example, you should never wash the balloon whisk attachment in it. Old silver (especially silver with damaged areas) shouldn't be washed in there either.
posted by LGCNo6 at 11:34 AM on October 25, 2005

Don't put glasses or china with gold or silver trim in the dishwasher; it will take off the trim very quickly. If you do put silverware in with stainless steel flatware, put them in separate compartments of the flatware holder as the stainless steel will cause black marks on the silver if they touch.
posted by Morrigan at 11:40 AM on October 25, 2005

What does it mean for something to be "dishwasher-safe"? This is not an exact science. Just because something does not explicitly say one can put it in a dishwasher does not mean harm will come if one does. Generally speaking there are several issues involved in dishwashing an item which could potentially case damage to that item.

1. Violent motion within the dishwasher. Hot water moves very quickly within the dishwasher, often causing items within to knock into each other. For very fragile items, such as glass stemware, this could cause breakage.

2. Heat. The temperature of the water in the dishwasher is hotter than one would use when hand-washing dishes. This is mainly a consideration for flimsy plastic items which could melt if fallen from the rack.

3. Water, water everywhere. Running an item through the dishwasher causes it to come in contact with a significant amount of water - muich more than handwashing. If you would not, say, put an item in a full bathtub, do not put it in the dishwasher. Most dishware is fine submerged in water but I'm thinking of perhaps some pottery or clayware which may not be fully glazed. Also solid wood things such as cutting boards or wood handles knives which could absorb watre and become warped. These items you would not want to put in the dishwasher.

4. Soap. The detergent sold as "dishwasher detergent" is typically much more caustic than liquid soap sold for handwashing dishes. This could have a negative effect on the nonstick coating used nowadays on many pots and pans, as well as fine silver items. Many cookware companies indicate that putting their non-stick cookware in the dishwasher would void the warranty on the items.

One thing to keep in mind is that the dishwasher is not some mystical thing. It just an appliance that sends hot, soapy water around a little box, followed by hot air.
posted by peppermint22 at 11:41 AM on October 25, 2005

When I was a kid I learned the hard way that Burger King Empire Strikes Back glasses were not dishwasher safe. Took the decals right off.

Boy, was I crushed.
posted by bondcliff at 11:47 AM on October 25, 2005

Ultimately, if it is your dishwasher, your dishes, your soap and your money on the line, the person who wishes to criticize your dishwashing decisions needs to shut up. If you know how a dishwasher can ultimately cause your beautiful wooden cutting board to fall apart and you toss it in anyway, then you're choosing to have several smaller pieces of wood in the long run.

And no, I've not had to tell relatives to stuff it when they loudly proclaim that I don't know how to load the dishwasher just because I don't do it like them. Nope. Never.
posted by onhazier at 12:02 PM on October 25, 2005

Well, the person doing the criticising is the co-owner of all of the above :) Hence the issue.

Her assertion is that the following may not be dishwashed: Knives (destroys the glue holding the handle on to the blade), Wood (I agree, there), and all pots (glue in handles, plus the finish). I don't agree with most of those, but would like to have something to back me up, if possible.
posted by ChrisR at 12:31 PM on October 25, 2005

Since this has been well answered, I'll venture slightly off-topic. Mr. Moonpie states "No knives, as detergents can dull them. How the heck can water and soap dull a knife? Rust a carbon steel blade, were you so unwise as to run one thru a dishwasher, but dull it? Like Albert Popwell's bank robber, I gots to know.
posted by mojohand at 12:32 PM on October 25, 2005

The Maytag site has dishwasher manuals in PDF format - here's a link to one for my dishwasher and on page 10 (the manual's layout numbering) there is a grid of what can and can't be washed - including (and this is the good part) why not for things that are not dishwasher safe.
posted by mikel at 1:14 PM on October 25, 2005

Well, mojohand, not for the reason I thought, actually. According to some experts (you know, the ones at the top of the Google search), they get dull from banging into other things.
posted by MrMoonPie at 1:27 PM on October 25, 2005

Dishwasher deterg. is abrasive, so the crystal and china from Gramma doesn't go in the dishwasher. The crystal will get that sandblasted look, and the gold rims will get washed off. Old knives used to be a problem, but not any more. Pots and pans - if you have pots and pans that are glued, you really deserve to cook with better requipment. They're sturdy; they'll be fine.
posted by theora55 at 1:48 PM on October 25, 2005

"Help me to deflect criticisms of my dishwasher usage. What sorts of dishes is it safe to wash in the dishwasher, and which ones are bad?"

If you're living with someone who is criticizing your use of a dishwasher, the best way to "deflect" the criticism might be to understand what is being criticized, and adopt the best practices of the manufacturers of both the dishwasher and of the dishes/cookware being washed, to deal with the problem. A lot of best practices information is also available from food products companies, and other sources of home economics information, including dishwashing detergent manufacturers. As boring as it sounds, reading the manual for the machine can help a lot, as will common sense practices manufacturers generally advise. As will using the correct kind of detergent, rinse aids, and additives, in the correct amounts, considering your water chemistry. Doing whatever preparation and maintenance of the machine is required to keep it running well, like cleaning strainers and aerator arms helps a lot. Wiping and pre-rinsing dishes that will not be done immediately helps to keep the machine working smoothly, and allows a small household to accumulate full loads, which can significantly reduce energy consumption.

Most dish and cookware manufacturers do testing to determine whether or not to label their products "dishwasher safe." Anything that isn't so labeled, probably isn't, at least over the long run, in that repeated washing in dishwashers can degrade at least the appearance of the item. This can range from water spotting, to fading of finish colors, to leaching of ceramic glaze ingredients, to physical damage of parts. Some items are also likely to damage the machine itself, or present an unusual propensity for damaging or contaminating other items being washed, due to their size, shape, or composition.

The major culprit in automatic dishwashing, that causes damage to dishes is the formulations of dishwashing detergent, which generally have some level of chlorine as a sanitizing and deodorizing agent. Chlorine reacts badly with a lot of metals and polymers, and its action is compounded by the comparatively high heat of a dishwasher, particularly one that is operated with a heated drying cycle, since small residues of dishwasher detergent may remain in areas of the machine after the rinse cycle, which are then capable of releasing free chlorine vapor during a heated dry cycle. Even materials you think of as being completely inert, like glass, can be permanently etched over time by repeated washing in a dishwasher. Following chlorine, the high heat of an automatic dry cycle can soften and deform plastic, wooden and metal parts of cookware. And finally, the mechanical actions of the dishwasher can move poorly loaded items into contact with one another, leading to chipping and scuffing of items being washed.

Things you can generally wash safely, many times:

• "Everyday" dishes, designated as "dishwasher safe" by their manufacturers. Corelle, ceramic white ware, undecorated drinking glasses, etc.
• Tempered glass bowls
• Dense, chemically inert, heat resistant plastics designated as "dishwasher safe". polypropylene cutting boards, ABS (Cyclolac) items such as Melmac dinner ware, and high temperature styrene plates and cups.

Things you may be able to wash, with some risk of appearance or function degradation over time:

• Stainless steel flatware
• Low end cookware
• Kitchen utensils
• Porcelain enamel cookware

Things likely to be damaged immediately in a dishwasher, or that can cause damage to the machine, or to other items being washed, or that are just dangerous:

• High quality cutlery
• Anodized cookware
• Cast iron cookware
• Fine china, especially gold or silver banded items
• Crystal, especially leaded crystal
• Painted or surface decorated items
• Wooden implements
• Plastic items which contain fillers like talc in the composition of the plastic
• Items with unusual shapes, or big differences in thickness or cross-section from one area to another (platters with thick bases and thin edges, etc.)
• Ceramics with low temperature or salt based glazes, or unfinished ceramics such as clay

posted by paulsc at 1:49 PM on October 25, 2005

Her assertion is that the following may not be dishwashed: Knives (destroys the glue holding the handle on to the blade), Wood (I agree, there), and all pots (glue in handles, plus the finish). I don't agree with most of those, but would like to have something to back me up, if possible.

I don't think any of my stuff has glue at all; it's all riveted. I'd be surprised if yours was different. I'd avoid putting any NONSTICK pots and pans in the dishwasher; while in small doses it's okay, in the long run it'll screw up the surface. I could give a shit personally if the surface of my stainless steel pans stop being as glittery.
posted by phearlez at 1:57 PM on October 25, 2005

Paulsc's summary looks complete to me. Nearly everything you buy for the kitchen will say whether or not it can be put in the dishwasher. Things in our house that are not allowed in the dishwasher (by wifely proclamation or because the manufacturer says not): cast iron skillets, wine glasses, hotel silver, our quality stainless steel cookware, wooden items, and china.
posted by jdroth at 2:06 PM on October 25, 2005

Don't mix stainless and sterling flatware--does nasty stainy things.
posted by wordswinker at 5:13 PM on October 25, 2005

tristeza: Oh, and never put a wooden bread board in the dishwasher. Why not?

Because the wood will absorb water and swell, leading to eventual cracks/splits. Wooden cutting boards are meant to be used dry only. (They also absorb bacteria and such, so no cutting raw chicken on them either!)
posted by blue_beetle at 9:42 AM on November 13, 2005