Wait, You Need to Clean Your Water Bottle *How* Often?

We asked the experts.

January 28, 2019
Photo by James Ransom

A quick scan of the office returning to work after the holidays yielded some interesting findings: enough nifty new lunch containers to inspire some serious meal-planning, and a smattering of shiny new water bottles on many a co-worker's clean and decluttered desks.

Everyone was looking so well-rested and hydrated, so high on being both environmentally-friendly and budget-minded. It got me thinking (as I waited in line to refill my own water glass): How often are these beautiful new reusable water bottles being washed?

I'm not here to point any fingers, but I did see those same bottles sit on desks for days on end, making me wonder whether any potential deleterious side effects could be lurking. I took my curiosity to the professionals to find out the proper cleaning frequency.

"Ideally once per day," according to Dr. Brian Chow, an infectious disease physician at Tufts Medical Center. "Or have a few bottles that you rotate through, and clean them all at once." He goes on to say that most of the bacteria found on the bottles come from us. "They are bacteria that live in our mouth and throat that our bodies know, and they don’t make us sick. However, if you share bottles with someone else, they may not be used to your bacteria or viruses. The germs that cause strep throat, mononucleosis, colds and the flu, and even bacterial meningitis can be spread by sharing bottles."

Sharing definitely does not mean caring in this case. Got it! But how bad is it really, not to wash these vessels on the daily? "In most cases, people with healthy immune systems will be okay going a day or two between washing bottles," says Dr. Chow, quickly alleviating my concerns. "However, all year round there are germs that can be transferred from other things we touch—door handles, light switches, faucets—to our hands, and then to the bottle, which we then drink out of. A quick wash and scrub at the end of the day and letting the bottle dry overnight is an easy step to keep you healthy while you stay hydrated."

Join The Conversation

Top Comment:
“We wash our water bottles every single time. We have plastic bottles that are dishwasher safe. I separate the tops into a plastic dishwasher cage that was leftover from when the kids were babies. After the bottles cool, I fill them 1/4 of the way with cold water, then freeze at a tilt (to maximize ice surface area.) To use, fill with tap water.”
— Kat H.

Sounds like completely sound and reasonable advice. Knowing what I know about our readership's preferences for specific water temperatures when washing dishes, you can bet there was a follow-up question. "Water that is hot to the touch is best," explains Dr. Chow. "While it may not kill all the germs directly, it does help dissolve the residue that allow germs to live on plastic and metal. Using soapy water and a scrub brush are as important (this removes the dirt and grime), and also dislodges the germs if they are stuck to the bottle."

It goes without saying, too, to check your bottle manufacturer's specified instructions as to proper cleaning methods. (Psst! Make sure it is, indeed, dishwasher-safe if you've been throwing yours in for a cycle.) I'd also suggest more frequent or thorough cleanings if your water bottle has a special spout with more intricate crevices.

Be honest: How often are you washing your reusable water bottle? Let us know below (no judgment)!
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See what other Food52 readers are saying.

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Hana is a food writer/editor based in New York.


Andrea February 16, 2019
I have a few Nalgenes that I use. Every once in a while, when there's one in the kitchen and I'm about to run the dishwasher, I'll throw it in. Other than that they get rinsed and air-dryed when I think about it, but that's about it.
Claudia T. February 9, 2019
I wash them every now and then, mostly when I feel like lip balm has gotten into the grooves around the mouth. If I just have water I try to at least let it air dry between uses *shrug* pretty blase about it I guess. I do tend to pick water bottles with wide enough opening that I can stick my hand down into to scrub around. I have a bottle brush but it's kind of a pain.
RisenWell February 8, 2019
I have 4 stainless steel bottles for car, favorite chair,bedroom&garden, and I wash them thoroughly once a month. I find it's not the bottles that are the issue, but the complicated tops (silicone, with or without attached straws) which require a toothbrush and toothpick to clean correctly
bernie N. February 8, 2019
when I was in the Marines in Viet nam I used the same 3 or 4 canteens the entire year and never washed them out I guess things were different 50 years ago
BeBee February 10, 2019
Thank you for your service, Bernie! Yes, I think things were different then... it’s a good lesson for us to realize microbes are our very own microbes!
Possibly that is what helps our immune systems.
Hope all will always be well with you, bernie.....
bernie N. February 10, 2019
Daniel H. February 7, 2019
Oh no, I can give myself KOOTIES??? More fear porn for the feeble people with no common sense about sanitation. Get a grip people, use the common sense you were supposedly born with! Sheesh!!!
Richard February 7, 2019
I never clean my plastic water bottle (although I do switch it monthly). I regularly drop in a teaspoon of raspberry vodka, shake it thoroughly and leave it overnight. Works for me and the next time I fill it with water, the water tastes so good! :-) (I do discard the vodka. lol)
BeBee January 31, 2019
You should check with the manufacturer of your plastic bottles. if you purchase bottled water ask the company. I’ve read certain plastic bottles are not to be reused due to chemicals in plastic being released over time, and freezing plastic bottles is not recommended due to chemical changes with the plastic affecting the contents.
The best thing would be to use glass or stainless steel and wash daily!
Let’s all stay healthy!!
Please consider the huge pollution problem that has collected in our environment, our cities and neighborhoods, landfills, and our oceans. You can make a huge difference by not using plastic. Please, please, please!
Please check out environmentally-informative websites.
POlySammo January 31, 2019
When I was in the hospital/ nursing home for 5 months after a colostomy I kept getting sick every time I tried to eat. I lost 80lbs. Once I was moved home I looked at the straw of my Starbucks cup that had been used for water. The green plastic straw hid the fact that there was mold in my straw. The nurses and CNAs kept refilling it but apparently were not washing it or the straw. No more colored straws and a good washing regularly.
Samantha P. January 31, 2019
I fill my S'well about 1/3 way with vinegar and shake it for awhile. Probably should also use soap and water, but I always get paranoid about not getting all of the soap out. :/
Kit L. January 30, 2019
BRB going to wash my bottle!

I wash my bottles at work (Swell or Swell knock offs) once a week, sometimes twice - usually Monday and/or Friday.

I wash my at-home bottles (same type) even less frequently! I figured since they're stainless steel there was less likelihood of "bad stuff" sticking to them. lol it's in the name - stainless, you know. ;) Guess I'll have to be more vigilant!
Chelsey January 30, 2019
Contrarian here: I have a water bottle at my desk and I honestly couldn’t tell you the last time I washed it. Maybe 2 months ago?? I know it’s gross, and yet... I’m 100% sure many of my coworkers (and plenty of other people) are doing the same thing.
Laura E. January 30, 2019
If I can’t get the family’s water bottle washed in dishwasher, I hand wash the spout then fill with hot water. Then I throw a Polident 3 minute cleaner in them. Voila ready to go.
It also helps that I don’t have small ones in the house anymore. I like the Klean Canteens with the spin off top. Easy to place in the bottom rack of the dishwasher. I wouldn’t try this with school age kids, though. Makes a mess if knocked over & their easy embarrassment level will be maxed.
Marysnn January 28, 2019
I use mine everyday take apart wash with detgerent and soap up and rinse inside out remove top clean lots of water hot and cold dry paper towel and let sit air out and cover
Mark D. January 28, 2019
I'll admit I go a week between washing my water bottle. It is almost never empty and I am constantly using it, even through the night as I wake up thirsty multiple times.
Elaine January 28, 2019
Seriously, what thinking person goes days at a time between bottle washing?! Gross!
Matt January 28, 2019
Extra flavor duh
Alie January 28, 2019
Apparently I'm not a "thinking person" lol
Laura E. January 30, 2019
Kat H. January 28, 2019
We wash our water bottles every single time. We have plastic bottles that are dishwasher safe. I separate the tops into a plastic dishwasher cage that was leftover from when the kids were babies. After the bottles cool, I fill them 1/4 of the way with cold water, then freeze at a tilt (to maximize ice surface area.) To use, fill with tap water.
JLH February 7, 2019
You might want to get rid of your plastic water bottles, they are not good for you. Even the plastic ones that ostensibly safe can be problematic. They can leach chemicals into your water over time. If you do some research on it you can make a good decision for yourself. I use stainless steel klean kanteens (the brand) and I guess I don't wash them often enough so I'll have to get on that.