Staying properly hydrated is a key component of good health. To drink enough H2O throughout the day, you might always keep a go-to reusable water bottle (dubbed by TikTok as the “emotional-support water bottle”) by your side. But if you’re like most people, there’s a good chance you're not washing your bottle as thoroughly or as often as you should. We don’t blame you—life gets hectic, and knowing how to clean a water bottle (and making time to actually do so) can fall to the bottom of our lists.
But keeping your water bottle clean is key. While a reusable bottle is better for the environment, not washing it properly and regularly can result in some undesirable results. That’s why we asked cleaning and food safety experts for their tips on how to clean a water bottle (and all of its accessories), plus how often you should be doing so.
Why It’s Important to Clean Your Water Bottle
Backwash from drinking can cause bacteria to grow in your water bottle, while stagnant water or other beverages can lead to mold—which is why regular cleaning and sanitizing is key.
“Bacteria are everywhere, including your water bottle,” says Jill Stuber, co-founder of Catalyst LLC, a food safety consulting and coaching company. Just like you regularly wash dishes and glasses from your kitchen, you should do the same with your water bottles, she says. Otherwise, mold and more bacteria can develop—and for the sake of your health, your water bottle isn’t a place you want them hanging out.
Frequent use without proper washing can lead to the growth of microorganisms that get trapped in the water bottle as they’re fed by the nutrients in our mouths, explains Bryan Le, PhD, a food scientist, faculty research fellow at Pacific Lutheran University in Tacoma, Washington, and author of 150 Food Science Questions Answered: Cook Smarter, Cook Better. “Over time, these microorganisms can form protective biofilms that become increasingly more difficult to clean,” he says.
How Often Should You Clean Your Water Bottle?
Experts recommend cleaning your water bottle after every use, meaning after you’ve finished an entire bottle. But if you’re refilling the same bottle all day long, it can get tricky to keep track. In these instances, “twice a day would be fine—once in the morning and once at night,” Le says. “More than that would be overkill.”
In addition to cleaning your water bottle once a day at minimum, you’ll also want to sanitize it at least once a week or every other week to ensure a deep clean. “Unlike regular cleaning with soap and hot water, sanitizing uses diluted bleach or hydrogen peroxide to kill off microorganisms that are resistant to regular cleaning,” Le explains.
Also important to note: Experts recommend washing reusable water bottles only, as single-use bottles weren’t designed to be used over and over again. “Single-use water bottles may not structurally hold up during the washing process, and their plastic material may break down over time, causing chemicals to leach into the contents of the bottle,” Stuber explains. “It’s better to recycle single-use bottles than to continually reuse them.”
When Should You Clean Your Water Bottle More Frequently?
Regularly cleaning your water bottle becomes even more important when you use the same one all the time. You’ll also want to commit to frequent water bottle washes if:
You use the same water bottle to hydrate during daily workouts
You’re sick, as your body will be shedding higher levels of microorganisms, some of which can potentially reinfect you if they grow in the bottle
You use it for drinking beverages other than water, such as juices or protein shakes, which can create the perfect breeding ground for microbial growth. “Sugary liquids such as powders or sports drinks that are left in the bottle for longer periods of time can accelerate the growth of fungi, no matter what the material the bottle is made with,” says Tonya Harris, an environmental toxin expert and author of The Slightly Greener Method.
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How to Clean a Water Bottle
A thorough water bottle cleaning includes the inside and outside of the water bottle, as well as any other parts, such as the straw and valve.
To effectively clean your water bottle, experts recommend the following steps:
Disassemble the entire bottle by removing any extra parts, such as the straw or valve.
Wash your bottle with hot water and soap. (Stuber recommends using an EPA-registered antibacterial dish soap for handwashes.) To wash inside, use a brush designed for bottle cleaning that can reach all areas. The same applies to straws, spouts, and the like. “A brush is important because invisible layers of bacteria known as biofilm can build up on surfaces if you don’t effectively, physically remove the bacteria,” Stuber explains. “This invisible layer protects the bacteria from any future cleaning, but the bacteria could still slough off and end up in your water.”
Rinse thoroughly to remove all soap.
Allow the water bottle and parts to air dry completely, as residual water can act as a source of moisture for the growth of microbes, Le says. “If you need to dry [your bottle] rapidly, use a clean towel,” Stuber advises. “Remember, even towels can harbor bacteria, so if it’s not clean, you’re more likely to recontaminate your bottle.”
How to Sanitize a Water Bottle
Remember: Your bottle needs a deep clean every week or two, or whenever you notice a slimy film on your water bottle or any of the parts. Harris suggests the following steps to sanitize a water bottle:
Wash the bottle thoroughly.
Fill the bottle up a quarter of the way with hydrogen peroxide.
Put the lid back on and gently shake the bottle.
Remove the lid and let the hydrogen peroxide sit inside the bottle for about 10 minutes.
Rinse and clean well.
Le says you can also sanitize your bottle by spraying it with a 1:1 mixture of hydrogen peroxide and vinegar, which is a food-safe way to disinfect surfaces. Alternatively, you can use a solution made with one teaspoon of bleach in one quart of water, he says. After rinsing, remember to let your bottle air dry completely before use.
If you have a dishwasher at home, feel free to use it to offset all the handwashing, so long as your bottle is dishwasher-safe. “Dishwashers can provide the luxury of washing and sanitizing all in one step, when available,” Stuber says.
How to Clean Water Bottle Lids and Straws
For pieces that are more difficult to clean, such as lids, straws, and valves, Le recommends soaking each part overnight in diluted baking soda, vinegar, hydrogen peroxide, or a combination of bleach and water.
If you have a bottle where the valve does not separate, Harris suggests opening the valve and running warm water through it, then using a soapy bottle brush to scrub the inside of the valve. Next, you should rinse it with warm water and then leave the valve or flip-top open to dry completely.
Are Certain Water Bottles More Hygienic Than Others?
With all this talk about cleaning, you may wonder if certain water bottles are better than others. Essentially, it comes down to material and design.
“Materials that stand up to abrasion will be easier to clean,” Stuber explains. “Softer materials are more prone to scratches that can harbor bacteria. Even in a dishwasher, the mechanical action of food particles flying around will begin to create those scratches.”
For that reason, glass or stainless steel bottles might be the better option for cleaning, Harris notes. (Glass bottles also make it easier to spot dirt, and biofilms don’t form as easily on glass.) But that doesn’t mean you need to ditch plastic or other soft-material bottles if they’re your favorite—just remember to give them a periodical inspection. “If they are starting to get beat up from use, it may be time to start fresh,” Stuber says. “Keeping good care of your water bottle will help extend its life.”
Additionally, experts generally advise against using bottles with lots of small crevices, as they’re harder to wash and allow microorganisms to grow. “If the water bottle is hard to clean, or has many niches that are hard to clean, or it’s hard to take apart, the likelihood of getting clean is limited,” Stuber says.
No one wants to add another task to their to-do list, but cleaning your water bottle daily and sanitizing it weekly is essential for not only your health, but also for the lifespan of your bottle. To help you get into the habit, try setting a reminder on your phone or calendar. Clean and sanitize your bottle following manufacturer instructions and/or the pro tips above, and always let it dry completely before drinking from it again. Happy (and healthy) hydrating!
This content is for informational and educational purposes only and does not constitute individualized advice. It is not intended to replace professional medical evaluation, diagnosis, or treatment. Seek the advice of your physician for questions you may have regarding your health or a medical condition. If you are having a medical emergency, call your physician or 911 immediately.