How to Clean a Water Bottle (And Why Yes, You Really Need To)

Give yourself a pat on the back for using a reusable water bottle. You’re taking care of your body and the environment, staying hydrated and reducing plastic waste. But let’s be honest: you really need to wash it.

Reusable water bottles are wonderful, but just like your kitchen sponge (which is really dirty), they tend to pick up a lot of bacteria. And that slightly musty odor? Rinsing it with more water isn’t going to make it go away. Instead, try our method to effectively clean your water bottle and restore it to a clean-smelling, bacteria-free accessory.

Struggling to get your 8-glasses-a-day? Here are ways to drink more water.

How to Clean a Water Bottle

Step 1: Make the Cleaning Solution

Fill your water bottle with around 4/5 water and 1/5 white vinegar ($3). Don’t use any other type of vinegar, in case the smell gets trapped inside the bottle—you don’t want your water smelling like apple cider vinegar. Leave some space at the top and add some baking soda—not enough to make the mix foam out all over the bottle, but enough so that the baking soda gets spread around. (Psst! Use up the box with these other baking soda cleaning ideas).

You can also use a tablespoon of bleach instead of vinegar—just don’t combine the two. (Here are more household cleaners you should never mix). Some people prefer to avoid bleach because it can leave an unpleasant odor behind, but it can thoroughly kill bacteria, and the baking soda should help remove odors.

Step 2: Let It Sit

Put the bottle in the sink and let it sit overnight. This will give the mixture time to thoroughly kill any bacteria hiding in the edges of the bottle, as well as dissolve any odor particles that are lingering there.

Step 3: Rinse It

In the morning, pour the mixture down the drain and clean out the water bottle. If you can run a dishwasher cycle, put the bottle in upside-down and use your dishwasher for a thorough cleaning. (Then give your dishwasher a thorough cleaning, too!)

If your bottle has a particularly small mouth, rinsing with hot water in the sink may be better. If you really need to clean the gunk out, this water bottle cleaning set ($10) is a good tool.

Step 4: Dry It (Thoroughly!)

Let the bottle dry out. Air drying is the best (and really only) option here, so be patient and wait for the water to evaporate before you use the bottle again. Don’t forget to give the bottle a thorough smell and sight test before refilling it with water, just to make sure that all odors and build-up are gone.

Now it’s ready to use again! Treat yourself and fill it up with one of these fruit-infused waters,

What happens if you don’t wash your water bottle?

The simple, dirty answer is that bacteria can build up—fast. Every time you place your bottle on the office lunch counter, touch a dirty doorknob before picking it up or let a friend take a sip, bacteria can transfer. And over time, when left unwashed, that bacteria can multiply.

Can reusable water bottles make you sick?

Yes. As we already mentioned, there are a multitude of ways bacteria can build up on your bottle. And some bacteria—like E.coli—can cause nausea, vomiting or diarrhea. Other germs, like the ones that cause the flu or cold symptoms, can also thrive on your water bottle and make you sick. The good news? Bacteria can be kept at bay with frequent, proper bottle washings. Did you know leftovers can make you sick, too?

Do you have to wash a new water bottle?

You don’t have to—but we highly recommend it. Many new water bottles—especially ones made from plastic—have a distinct fresh-from-the-package smell that a little soap and water can wash away. Plus, just think of where your bottles been before you purchased it. Retail workers and other customers have likely touched it, and before that it made its way through a whole delivery chain. For peace of mind, it’s best to give your bottle a quick wash before you take the first sip.