March, I wrote about a tenant of mine who complained about a bad smell
in her dishwasher, and when I went over to her apartment to investigate,
I discovered that she had been cooking fish in her dishwasher. I later
found out that she was also making grilled cheese sandwiches with a
clothes iron. I asked her if her stove was working OK, and she said it
was, but she said she didn’t like to cook food on the stove. She
preferred to cook food with household appliances, but I never found out
why. So – maybe it is time that I listed some of the things that people
put in their dishwashers but shouldn’t.
Food. Don’t cook
food in your dishwasher. There are a lot of recipes online for food you
can cook in a dishwasher, but you can get sick eating food that you
cooked in a dishwasher. The temperature inside a dishwasher may not get
hot enough to kill microorganisms like salmonella. Use your stove to
cook food. Sharp knives. Always hand wash sharp knives, cheese
graters, slicers, and anything else that has an edge to it. They can
become dull or nicked in your dishwasher. Wooden items. Wood
salad bowls, cutting boards, and utensils with wooden handles should be
hand washed. The wood can crack and warp in a dishwasher. Cast-iron cookware. Washing
cast-iron cookware in a dishwasher strips off the baked-on oil and
seasoning that gives cast-iron cookware a slick surface and prevents
rusting and food from sticking. Computer keyboards. Yes, it is
hard to clean a computer keyboard, but if you put in your dishwasher,
water will get inside the keyboard and probably ruin it. Footwear.
It may seem like the easiest way to clean waterproof footwear like
Crocs and flip-flops is by putting them in the dishwasher, but the heat
in your dishwasher can warp and shrink footwear and make it brittle. Delicate clothing. Some
clothing items, like wool sweaters, silk scarves, and bras say on them
that you shouldn’t put them in a washing machine or clothes dryer. That
doesn’t mean that is safe to put them in a dishwasher instead. Insulated
mugs. Water and heat can damage the vacuum seal between the inside and
outside layers of the mug. Once the vacuum seal is broken and water gets
inside, the mug will permanently lose its ability to retain heat or
cold. Dishwashing liquid. Never put dishwashing liquid in a
dishwasher! Only use dishwasher detergent. Dishwashing liquid is
designed to make lots of bubbles. Dishwasher detergent is not. If you
put dishwashing liquid in your dishwasher, your kitchen could be flooded
with bubbles. Even if that doesn’t happen, your dishes will likely be
left covered with a sticky soapy film. Non-stick pans. Washing non-stick cookware in your dishwasher will shorten the life of the non-stick coating. Electric appliances. (This is the most dangerous!)
A lot of people put small electric appliances in their dishwashers,
things like coffee makers, blenders, hair dryers, and popcorn makers.
You should never use an electric appliance that has been in a
dishwasher. Toss it out! Put it in your garbage can before you get
What was the strangest thing that a tenant of mine
put in his dishwasher? Well, I once had a tenant who put an expensive
North Face tent in his dishwasher. The heat from the dishwasher shrank
the fabric so much that it would no longer fit on the tent poles. He
also put his hiking boots in the dishwasher. They were also ruined. He
expected me to buy him a new tent and hiking boots. Predictably, he
blamed the dishwasher. I refused to pay him, which surprised him, but
not his roommates.
A couple of years ago, a
tenant called me on the phone and told me that her dishwasher smelled
bad and that the bad odor was getting worse. I went over to her
apartment, sniffed inside her dishwasher, and said: “Your dishwasher
smells like fish. Do you know why?” She told me that she didn’t know why
but that maybe – just maybe – it was because she had been cooking
salmon in her dishwasher. That left me confused. She then showed me a
cookbook with a recipe in it for salmon cooked in a dishwasher. This was
something that I had not heard about before. I told her to stop cooking
fish in her dishwasher and to run the dishwasher twice with nothing in
it except dishwasher detergent. When I got home, I went online and
searched ‘fish cooked in a dishwasher.’ To my surprise, I found dozens
of recipes for fish cooked in a dishwasher. (No. I’m not making this up,
although this story may sound just too bizarre to be true. Go to Google and check it out for yourself.)
Cooking fish in a dishwasher is a really bad idea,
no matter what anybody tells you. Predictably, your dishwasher will
smell like fish. Even worse, cooking fish in your dishwasher could make you very sick. The heat in your dishwasher may not be sufficient to kill parasites and dangerous microorganisms like salmonella.
The temperature inside a dishwasher doesn’t get anywhere nearly as high
as the temperature inside an oven. That’s why there are plastic parts
inside your dishwasher, but there are no plastic parts inside your oven.
I also found recipes online for chicken, turkey, eggs, lobster, and
lasagna cooked in a dishwasher. You should never cook food in your
dishwasher. It isn’t designed for that. (Yes, everyone knows that
you have to be very smart to get into U.C. Berkeley, but unfortunately,
the SAT doesn’t have any questions on it like: “Should you cook fish in
your oven or your dishwasher?”)
can’t figure out why anybody would want to cook fish in a dishwasher.
If an apartment has a dishwasher, it also has a stove. There are lots of
apartments that have a stove but no dishwasher, but I’ve never seen an
apartment that had a dishwasher but no stove. Take a look at the photo
below. I copied this photo from a recipe for salmon cooked in a
dishwasher on the Realtor.com web site. It seems to me that they should
know better than to recommend something like this. Look at this photo
and ask yourself – What sort of person would look at this picture and
not immediately know that there is something wrong – very wrong – with
People put the strangest things into their dishwashers. I once had a tenant who ruined an expensive pair of hiking boots by washing them in his dishwasher. Here is a list of things that you should never put in your dishwasher.
Wooden items. The water and heat inside a dishwasher can warp and crack wooden items, like salad bowls, cutting boards, and utensils with wood handles, like steak knives.
Cast iron cookware. Seasoning prevents cast iron cookware from rusting, but a dishwasher will remove it.
Non-stick cookware. Most non-stick coatings do not hold up well in the dishwasher.
Aluminum cookware. Aluminum pots and pans can oxidize in a dishwasher and turn dull or even black.
Insulated mugs. The heat of a dishwasher can damage the vacuum seal between the inner and out walls. Once that happens, the mug will lose its ability to retain heat.
Sharp knives. They will lose their edge.
Dishes with big pieces of food on them. You don’t have to rinse dishes before loading them in your dishwasher, but you should scrape food off of them first.
Crocs. It might seem that the easiest way to clean Crocs and other rubbery footwear is to put them in the dishwasher, but the heat in a dishwasher can shrink and warp them.
Computer keyboards. Yes, people have done this. I know how hard it is to clean a computer keyboard and get the dust and dirt off the sides of the keys, but you will ruin your keyboard if you put it in a dishwasher.