Why You Need to Wash Your Reusable Water Bottle, Like, Right Now

You know how important hydration is for everything from weight loss to fitness to sleep, so you’ve been toting around your BPA-free water bottle forever. But have you ever really cleaned it?

If your version of cleaning means giving your bottle a rinse once every few weeks or months, that’s not enough. If you want to avoid things like diarrhea and bacterial infections, you need to be washing your water bottle with soap and water every day. While this might seem like a chore, it’s important to remember that water is not totally sterile. Even water filtered, treated and used to fill disposable plastic water bottles has been found to contain seven different kinds of bacteria just three weeks after bottling!

Water bottles are moist environments, and the constant sipping from them you do to keep yourself hydrated transfers germs from your mouth to the bottle, which, thanks to the bottle’s wet, often dark environment, are in the perfect place to multiply and grow, potentially giving you a bottle full of bacteria if you’re not vigilant about cleaning. Water bottles can even grow mold, especially if you favor bottles with a slide top lid.

It’s important to remember that all water bottles are not created equal; some are more prone to bacteria growth than others, so the next time you’re on the hunt for a new hydration vessel, go for a straw top or screw top bottle, as these end up generating about as much bacteria as that of the water from your kitchen sink, which we’ve all sipped from in a pinch.

If possible, go with a wide-mouthed stainless steel version, as stainless steel is naturally anti-bacterial and doesn’t crack like plastic, which can collect bacteria is those small cracks and crevices. Wide-mouthed water bottles are also easier to clean. Stay away from squeeze tops, however, because while they harbor less bacteria than their slide-top counterparts, the bacteria they do contain is the far scarier, more harmful bacteria, including E. coli.


Now that you know what a dirty water bottle can do and how to buy the best water bottle for your health, the question remains: What’s the best way to clean it? Yes, there’s soap and water involved, but it gets a bit more nuanced than that.

If your bottle is dishwasher safe, place it on the top rack of your dishwasher with the bottle, mouthpiece, cap, and straw taken apart. If your bottle is hand-wash only, wash it with warm, soapy water using your regular dish detergent. Use a sponge or bristle brush to get into the very bottom corners of the bottle, as well as the top and mouthpiece, where bacteria can hide even after washing. Bottles are best dried upside-down to prevent fungal growth inside the bottle. Most importantly, wash your water bottle every day after use — no questions!