Key Takeaways

Reusable water bottles provide a lot of benefits: They can help youstay hydratedthroughout the day, keep water at a desirable temperature for long stretches of time, and they’re great for the environment.

But it’s important to clean reusable water bottles—including the beloved Stanley Cups—consistently, according to experts.

These bacteria and fungi can cause your bottle to have a bad smell or even affect the taste of the water inside it.

It’s important to clean the wholewater bottle, especially the part you sip from,Pratik Banerjee, PhD, associate professor of Food Safety at the College of Agricultural, Consumer, and Environmental Sciences at the University of Illinois Urbana-Champaign, told Verywell. “The dispensing area of the water bottle—that needs special attention when it comes to cleaning because our mouth has bacteria,” he said.

Simply rinsing it out every now and then doesn’t qualify as “clean” either; you’re going to want to thoroughly scrub (or dishwash) your tumbler to prevent illness or other unwanted circumstances.

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How Often You Should Clean Your Stanley Cup

When it comes to washing your reusable water bottle, there’s no one-size-fits-all rule. “People have to decide for themselves,” Snyder said, adding that she cleans her water bottle after every use.

A recent survey showed most Americans don’t do this: 42% of survey participants said they cleaned their reusable water bottle about once a day; 25% said they cleaned it a few times a week; and 13% said they cleaned it a few times a month. Only 20% of people said they cleaned their water bottles multiple times each day.

“There is no general rule of thumb here, or scientific studies that have looked at cleaning routines and their impact on, say, the growth of microbes in water bottles,”Joe Brown, PhD, PE, associate professor of environmental sciences and engineering at the Gillings School of Global Public Health at the University of North Carolina, told Verywell.

When thinking about how often you wash your tumbler, consider this: The longer you go between washes, the more likely you are to have a build-up of bacteria or fungi.—ABBY SNYDER, PHD

When thinking about how often you wash your tumbler, consider this: The longer you go between washes, the more likely you are to have a build-up of bacteria or fungi.

—ABBY SNYDER, PHD

That’s not to say that you have to wash it between uses or even daily: Banerjee recommended cleaning your reusable water bottle every five to seven days to ensure bacteria and fungi aren’t growing inside it.

Washing your reusable water bottle every five to seven days is a pretty safe bet, but certain circumstances warrant cleaning it more frequently, he added.

If you put other beverages into your tumbler—such as coffee, tea, or sugary drinks—or if you share it with other people, you should wash it after each use, Banerjee explained. “I would say if you use anything apart from water, you definitely need it to be cleaned as soon as it’s empty,” he said. “You do not want to reuse it without cleaning.”

You might also want to consider cleaning it more frequently if you refill your bottle often throughout the day or use it in public spaces (such as at the office or on public transportation). Remember that it’s not just the inside of the water bottle you have to worry about—bacteria can also accumulate on the bottle’s exterior.

If you’re guilty of going weeks—or longer—without cleaning your water bottle, that doesn’t mean it’s irredeemable. You can simply start cleaning it consistently to avoid risk.—ABBY SNYDER, PHD

If you’re guilty of going weeks—or longer—without cleaning your water bottle, that doesn’t mean it’s irredeemable. You can simply start cleaning it consistently to avoid risk.

Exactly how often you clean your water bottle may depend onhowyou clean it, Banerjee added. “Dishwashers will do more comprehensive cleaning that the hands can’t actually do,” he said. Therefore, he recommends putting your water bottle in the dishwasher once a week or hand washing it about once every five days.

This goes for all types of water bottles, including those made of stainless steel, glass, plastic, or other materials. All can become dirty after multiple days of use, Banerjee said.

“Some metals like copper or silver are bacteriostatic, [meaning] they can prevent microbial growth and the development of biofilms, but most water bottles are either stainless steel, glass, or plastic,” Brown said. Therefore, the frequency with which you wash your water bottle shouldn’t change depending on what kind you’re using.

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How to Clean a Reusable Water Bottle

If possible, you should use a dishwasher to clean your Stanley Cup (or other reusable water bottles). Before doing so, check to make sure your container is dishwasher-safe so you don’t damage it if it isn’t, Banerjee said.

Though the lower racks in most dishwashers are thought to be more efficient, it doesn’t necessarily matter which you use for your water bottle; the “normal” setting should do the trick regardless.

Some water bottles have multiple parts that can be screwed on or removed, and it’s a good idea to break everything down before cleaning it. “A good suggestion is to disassemble the parts” to make sure they all get clean, Snyder said.

Some have touted the use of rice water to clean containers like water bottles, but that’s not risk-free, Brown said. “Rice water can sometimes be useful to clean things because the particulates in it can help scrub surfaces, but unfortunately, rice water also contains starches that can feed microbial growth,” he explained. “Soap and water is hard to beat.”

If your water bottle is damaged in any way, it can be harder to thoroughly clean bacteria and fungi from the device. This may mean it’s time to consider buying a new reusable water bottle.

“Things that would cause me to get rid of a water bottle are if it becomes damaged and you see microcracks, or crevices, in the plastic, or if you warp some part of it and it doesn’t fit correctly anymore,” Snyder said. “Those would be the cues I would use to decide it’s no longer cleanable.”

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What This Means For YouThough rare, bacteria and fungi growing inside reusable water bottles can cause illness. They can also cause unpleasant side effects like a bad smell in your water bottle. To avoid these circumstances, you should clean your water bottle consistently. If you’re only drinking water from it, washing it every five to seven days may be safe. But if you put other beverages in it or if you share it with others, you should wash it between each use.

What This Means For You

Though rare, bacteria and fungi growing inside reusable water bottles can cause illness. They can also cause unpleasant side effects like a bad smell in your water bottle. To avoid these circumstances, you should clean your water bottle consistently. If you’re only drinking water from it, washing it every five to seven days may be safe. But if you put other beverages in it or if you share it with others, you should wash it between each use.

1 SourceVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.WaterFilterGuru.com.Swabbing water bottles: how clean is the water you drink?.

1 Source

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.WaterFilterGuru.com.Swabbing water bottles: how clean is the water you drink?.

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

WaterFilterGuru.com.Swabbing water bottles: how clean is the water you drink?.

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