How to clean and care for your steel reusable water bottles

You've seen the evidence, read the studies, made your choice. You invested in one or more steel reusable water bottles to keep hydrated and help the planet.

Now you have to keep the thing intact to ensure you keep the reusable part for as long as possible. Unfortunately, to keep your water bottle in top shape, you need to make it a place inhospitable to the growth of millions of lifeforms.

The microbial growths that form in warm, dark, and moist conditions have bad things in store for you. To keep them out of your water, and out of your body, while conserving resources, you need to not only clean but clean smart.

This guide will give you a top to bottom view of how to maintain your investment. 

Maintaining Reusable Water Bottles

Fortunately, by choosing a stainless steel or aluminium water bottle you avoid the first tier of issues in keeping a bottle ready to go. Rust, the terrible product of iron atoms and oxygen, won't affect your reusable water bottle. 

This is because rust doesn't affect your materials of choice. 

The only thing you need to worry about is the growth of mold and bacteria that can occur. To combat these, you will need to wash your bottle often, with the right technique, and avoid causing damage to the bottle.


How often you should wash even the best reusable water bottles is a tricky question. The longer you wait between washes, the more time microbial growth has to occur. Washing too frequently and the amount of water you use on getting the bottle clean becomes unjustifiable.

A few different factors aid in the growth of microbes. Each one you restrict lengthens the time between necessary washes.

First, understand that the bacteria growing in the water bottle don't just randomly appear. The vast majority come from your mouth, where they take root and flourish with time. The cleaner your mouth, the fewer microbes hit the bottle. 

Second, microbes also need nutrition. They also get this from your mouth. Sugars and fats in particular.

The aforementioned study indicates that growth drops after a day of disuse. This is because the microbes run out of things to eat. 

A wash every day is ideal if you are washing other things and have soapy water for use. Otherwise, growth caps off at four days, so anything before that is ideal.


The best way to wash a reusable water bottle is with plain old soap and warm water. This kills what's in there and doesn't take a lot of effort.

Threads along lids and caps should be soaked for a few minutes to get in the nooks and crannies. Rinse thoroughly and continue on. 

On the go, you can use diluted hydrogen peroxide or cleaning tables (like for dentures) to soak the bottle clean. This is an excellent way to refresh your bottle on a long backpacking excursion. 


You want to avoid using bleach and vinegar/baking soda combos. These overly caustic chemicals can deteriorate the finish on your bottle. They also tend to be overkill unless the bottle was used to store something other than water for a duration. 

Save and be Safe

By and large, the microbes in your water bottle are the microbes in you. A scant percentage of them are dangerous. You want to wash reusable water bottles twice a week at the least to keep them in good shape and conserve resources. 

Speaking of resources, check out other handy articles right here.

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