How Gross Is It Not to Wash Your Water Bottle Every Day?

Experts weigh in on whether it’s okay to go a few days between cleanings.

Updated on December 20, 2022

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Photo by: Tatiana Maksimova/Getty Images

Tatiana Maksimova/Getty Images

Admit it, you’ve skipped a day (or maybe five) without giving your reusable water bottle a proper scrubbing. Which is your favorite rationalization? “It’s just water in there,” “I washed it yesterday,” or maybe “It’s BPA-free, so I’m good?” Staying hydrated and doing you part for the environment by opting for a reusable bottle are commendable, but don’t sabotage those healthy habits by exposing yourself to potentially unhealthy and harmful bacteria. Find out how germy those bottles get if you skip daily cleanings.

What Happens When You Dont Wash Your Water Bottle?

Let’s cut to the chase: Yes, it’s seriously gross to skip cleanings. Lisa Cuchara, PhD Professor, Biomedical Sciences at Quinnipiac University in Connecticut confirms what you’ve always feared about drinking out of bottles that aren’t regularly washed. This healthy habit can come with gross friends. Bacteria. Bacteria from your backwash, bacteria that thrive on sweat, bacteria that develop biofilms, bacteria that could make you sick, E. coli poop bacteria and even antibiotic resistant bacteria, she warns.

What’s a biofilm? We wanted to know, too. Turns out it’s a slimy surface layer of bacteria that you may have already noticed forming on your trusty water bottle. According to Cuchara and a study by Treadmill Reviews, drinking from the average refillable bottle is more than 100 times worse than licking your pet’s favorite chew toy.

Best Water Bottles For Keeping It Clean

When choosing a water bottle, steer clear of vessels with small mouth openings and pop caps or slides that you need to manhandle to open.

Cuchara suggests wide-mouth stainless steel water bottles. The smaller the number of surfaces for bacteria to hide and grow in, the better, she says. “Stainless steel is easier to clean and harder for bacteria to create biofilms on. There’s no need to toss out other bottles you already have, but you may want to put in some extra effort to get them clean.

How to Wash Your Water Bottle

Washing isn’t optional. For best results, run through the dishwasher. Bottles can also be washed with soap and water, or a weak vinegar or bleach solution. Rinse well and allow to dry upside down. Food safety expert Toby Amidor suggests a thin stiff-bristled brush can also be used to clean the inside of a bottle along with soap and warm water. But avoid using those dirty dish towels to dry it or you can re-contaminate it!

A final tip from our germ guru Cuchara is to fight the habit of letting your water bottle sit in your gym bag or car, or bringing it into the bathroom. Those are just more opportunities for germs to be introduced and grow.

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