Get access to everything we publish when you sign up for Outside+.
You’re about to head out for a run and go to reach for your water bottle. As you pop open the cap to fill it up, it hits you: that not-so-fresh scent of mildew. Or maybe there’s still sticky stuff in there left over from last week’s drink.
If it’s really bad, you may be tempted to toss it in the trash. But before you pitch it, read on for expert tips to save it—plus simple ways to keep your bottle squeaky clean (and stink-free!).
Finished your run? This simple solution is easy enough to do after every use: Drink up—and then hit the sink. Right after you use the bottle, empty it completely, then fill it with warm soapy water, suggests Carrie Higgins, author of the book Organization Hacks. “Close the cap and shake it for about a minute, drain the water through the cap and rinse until the water runs clean,” she shares. Let it dry uncapped overnight before you use it again.
For smaller bottles, like handhelds or hydration belt flasks, you’ll want to do a full warm, soapy water soak of both the bottles and caps for a few hours to overnight to get the gunk out.
Try A Tablet
Sometimes dish soap alone just doesn’t do the trick. Say you’ve got remains of a drink powder or a hydration tablet from last week’s run still in there—to get rid of the residue, fill half your bottle with cold water and drop in an effervescent tablet, which can disinfect and remove any residual odors or tastes, says cleaning guru Julie Finch-Scally. “After five minutes, screw the top onto the bottle and shake it so that the entire bottle is coated.” Wait five minutes and shake again before emptying the bottle and rinsing with hot water.
Scrub It Out
After soaking your bottle, scrub every inch of it—including the inside of the screw top—with a bottle brush and hot water. Need a narrow brush? “Look for the long brushes they sell for cleaning baby bottles,” since they run in sizes from standard to extra skinny, says Finch-Scally.
Get Rid Of The Gunk
Letting water linger in a closed bottle traps moisture, which leads to all of the icky stuff you can imagine—from mildew to mold. And leaving it in a warm, humid place (say, rolling around underneath your car seat) is an open invitation for bacteria. The good news? You can usually wash away even the grossest gunk in your bottle.
For a super-stinky bottle or one with mold spots, reach for the vinegar. Higgins suggests soaking the bottle and cap in a mixture of one part white vinegar, five parts water, and letting it soak for several hours. Then scrub the inside and let it dry overnight. “Technically, you can use a water bottle that has had mold in it if it’s been cleaned, scrubbed and disinfected thoroughly,” says Higgins. But if the spots are super stubborn? Better to be safe and throw it out than get sick.
Newer dishwashers can come with specific bottle cleaning features, but if you don’t have an appliance like that you’re going to be left scrubbing it by hand. Do a bang-up cleaning job on your bottle with these items.
Brush Up: Stock up on a brush kit made especially for bottles. The OXO Good Grips Water Bottle Cleaning Set ($10.99) has a large bottle brush, a skinny straw brush and a looped detail-cleaning brush all on one ring that you can snap off as needed.
Budget Option: Try cleaning narrow openings in the lid or a straw with a pipe cleaner or cotton swab dipped in dish soap.
Get Fizzy With It: Pop in a cleaning tablet made just for water bottles, add a little water and let it do its thing to lift dirt from the surface and get rid of odors and stains. Try Bottle Bright Cleaning Tablets ($8 for a 12-pack).
Budget Option: Denture cleaners do the same trick in removing mineral deposits from hard-to-reach places. Just make sure to buy the non-flavored kind unless you want all of your bottles to taste minty fresh. Try Efferdent Anti-bacterial Denture Cleanser ($5.68 for 126 tablets).