The Dirty Truth About Reusable Water Bottles

The Slightly Greener Life | Episode24

October 13, 2023

How often do you wash your reusable water bottle? After hearing this, you might be stepping up your washing game (I sure did)!

Did you know that the average reusable water bottle is 40,000 times germier than a toilet seat and 14 times germier than a pet’s water bowl? Yep, that’s what a study by Water Filter Guru found out! And those are just a couple of the dirty secrets about reusable water bottles.

A few months ago I was excited to be asked by Southern Living to weigh in on some questions about how often to clean your water bottle. And while I thought I knew, I was still shocked by some of the statistics, like that one!

And then I asked my kids how often they clean their water bottles. And to be honest I don’t remember what they said, because I seriously think I am blocking the answer from memory. And remember – they are 19, 21, and 25 so I don’t really have much control over their water bottles anymore – all I can hope for is to give them the info and hope they do the right thing – eventually.

So how often should you clean your water bottle? Once a day for sure, but there are some other factors that may mean you should be washing it more.

And what is the safest type of water bottle? Because believe it or not, certain surfaces allow more mold and bacteria to grow.

Find out the answer to these questions (and more!) in this week’s podcast episode, and see below for the best way to clean your reusable water bottles!

nontoxic water bottles

What’s the best way (or ways) to clean a water bottle? 

Use a bottle brush and straw cleaner to make cleaning easier. I like this set from Amazon because it has both (not an affiliate link – just a product I recommend and that is easy to order!).

To clean daily:

  1. Start by unscrewing the lid, and removing any parts that can separate – straw, any valves, etc. that are meant to be removed to clean.
  2. Use a bottle and a straw brush to clean the bottle and lid (and straw, if applicable) with warm, soapy water.
  3. Use a clean bottle brush to thoroughly scrub the inside walls of the bottle, making sure to reach the bottom, with the soapy water.
  4. Use the smaller straw brush to get the interior of the straw, and to help scrub the tiny crevices around the lid if needed.
  5. Rinse the top and bottle well with warm water until it runs clear.

Be sure to let the components dry completely. I like to recommend doing the clean at night (except in the cases where it is recommended to wash them more – if sick, eating, sugary liquids, etc.).

This way you can clean your bottle, then turn it upside-down to completely dry. I like to set by bottle, lid, and straw upside-down on a clean dish towel or paper towel so the components can dry overnight.

I like to clean and sanitize the brushes also, by throwing them into the dishwasher, where the heat can sanitize them.

To clean the straw:

Run warm water through the straw, then add a small amount of dish soap to the brush, and scrub the inside of the straw. Follow by running warm water through the straw until it runs clear. 

To clean inside a valve or flip-top that does not separate:

Open the valve and run warm water through the valve and clean the same way you do with the straw. Use a soapy bottle brush to scrub the inside of the valve, then run warm water through it to rinse. Leave the valve or flip-top open to dry completely.

Here are 3 ways to sanitize water bottles once or twice a week:

  1. If the bottle is dishwasher-safe, place it in the dishwasher so the heat setting at the end can sanitize the bottle and lid.
  2. Use white vinegar. To use this method, clean the bottle with warm soapy water and rinse. Then fill the bottle with a 50/50 combo of warm water and white vinegar.
  3. Put the lid on and give it a little shake, remove the lid, then leave it to sit overnight. In the morning, wash with warm soapy water as usual and rinse.

If there is a slimy film in the water bottle, it’s easy to remove with hydrogen peroxide (look for 3% on the hydrogen peroxide bottle label). Simply wash the bottle, then fill the bottle about a quarter of the way up with hydrogen peroxide, put the lid on, and give the bottle a gentle shake. Remove the lid, and let the hydrogen peroxide sit for 10 minutes and rinse and clean well.


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