As wonderfully convenient as
dishwashers are, they are not all-purpose miracles of technology that you can
entrust with cleaning anything you can get your mitts on. It’s surprising how
many people have to learn this the hard way. While some things may survive a
run or two, certain items should never be put through a dishwasher cycle.
Here’s a rundown of what not to do.
Never
Put These in Your Dishwasher
• Cast Iron: The inside of an
active dishwasher is hot and wet—two conditions that are disastrous for certain
kinds of cookware. Not only will dishwasher cleaning cause cast iron skillets
to rust, it will also wash away the seasoning—that protective, nonstick, and
delicious layer of oil and lard. Unless you want your cast iron cookware to end
up looking like some sort of prehistoric anvil, don’t put it in your
dishwasher.
• Wood: Once again,
dishwashers get hot—really hot. Heat causes wood to warp, so avoid putting
wooden objects in your dishwasher. That includes utensils, bowls, cutting
boards, and even pots and pans with wooden handles. Furthermore, the dry cycle
may cause the wood to crack, opening up a breeding ground for bacteria.
• China and Delicate Glassware:
This one should be obvious: Don’t put delicate wine glasses, china, or other
formal wares in your dishwasher. What are you thinking? The chemicals in
dishwasher detergents are abrasive, so they’ll wear away at delicate materials
and cause them to crack. The intense heat of a dishwasher can also cause
glasses and china to shatter, which is sure to put you at odds with whoever
owns those precious family heirlooms you were too lazy to wash by hand. Not to
mention, you’ll have to manually clean shattered glass out of the wash tub,
which sounds like a blast but is probably hazardous, to say the least.
• Gold-Trim Dishes: What, are
you stupid? They’re almost always delicate (see above), and even if they don’t
wreck the entire plate, the water jets can spray away flakes or chunks of gold.
• Insulated Travel Mugs:
Travel mugs have a vacuum seal between the inner and outer shell, which can be
breached when it’s put through the dishwasher. Aside from filling the vacuum
with water for an annoying sloshing sound, it can hinder the mug’s ability to
retain heat, thereby defeating the whole purpose of a travel mug.
You
Probably Shouldn’t Put These in Your Dishwasher
• Teflon: There’s a lot of
debate over this one, but we’ll go ahead and say you probably don’t want to put
Teflon in your dishwasher. Recent research has suggested that polytetrafluoroethylene—the
chemical name for Teflon—is carcinogenic, particularly when it begins to break
down. That reason alone should be enough to scare you away from the idea of
agitating it in a high-temperature alkaline box. Manufacturers like Dupont say
it’s fine, and dishwashing it a few times over several years is probably okay.
But frequent washing is likely to hasten the breakdown process, coating other
dishes and utensils with undesirable chemicals. And honestly, how easy is it to
wash nonstick pans by hand anyway? Don’t be lazy.
• Stainless Steel: Most
experts say it’s okay to put stainless steel products in the dishwasher—but
with a few caveats. The general fear is that detergent and excessive humidity
will corrode the metal, and that acidic food soils will tarnish its polish.
It’s also recommended that, if you do choose to put stainless steel in the
dishwasher, it should be placed in the upper rack or the cutlery basket and
spaced far enough away from other materials so as to ensure proper washing and
drying. However, we feel there are far too many precautions, and that you’re
better off just washing stainless steel by hand.
• Aluminum: Some aluminum
products are specifically designated to be “dishwasher-safe.” These materials
are probably fine, but others may be prone to scratching. They may also develop
a dull finish over time. We’d recommend taking this category on a case-by-case
basis.
• Knives: Knives turn into
sporks when put through the dishwasher. OK, not really, but they do dull over
time in the dishwasher. Then you have little more than a blunt object for
cutting vegetables, and you’re no troglodyte, so wash your precious
blades by hand. Just be careful.
• Plastic: If a plastic item
is not clearly guaranteed “dishwasher-safe” by the manufacturer, then wash it
by hand. The heat from the water and dry cycle can warp the material and
possibly even melt it. Even if the item is deeded safe for the dishwasher it’s
a good idea to place it in the upper rack—or as far away from the heating
element as possible. But anyone who’s ever had to deal with melted plastic in
their dishwasher might recommend staying on the safe side and avoiding it
altogether.