Cases of handheld size water bottles grace my garage since I buy them in bulk when they go on sale. Sometimes the specials are as great as buying two cases and getting two for free. However, I did feel guilty disposing of so many water bottles each week and was thinking about investing in a reusable water bottle instead. Then I could put the empty bottle under the spout of the kitchen water cooler and eliminate all the access to throw away water bottles that will end up in landfills or other recycling venues.

Reusable water bottles come in an infinite variety and styles. An attractive water bottle makes a statement about its owner. Perhaps he or she is a sports enthusiast and displays their favorite team in bold letters. Another possibility is a personalized bottle that proudly showcases a woman’s grandchildren. She may have received that bottle as a birthday gift and each day that she uses it she is reminded of how cute those babies are.

Another advantage of reusable bottles is their size variation. People who are on specific diets must drink a certain amount of water each day. By filling up their jug in the morning they can spread out their water consumption evenly throughout the day. Some bottles are heavier in weight and that could be a plus while walking instead of weights. Those bottles come in metal and plastic depending on what the owner prefers. Plastic weighs less but tends to smell while metal is heavier and less likely to develop unpleasant odor.

In 2024 alone, the world market for reusable water bottles was about $10 billion. When Italian health care employees were asked what type of water bottles they used, half of them answered the reusable type. Over 50% of university students surveyed were users of reusable water bottles.

Are Reusable Bottles Clean Enough?

Surprisingly the short answer is no. If you are lucky enough to be a parent of an infant, you know how carefully you must wash their baby bottles. It’s not enough to wash them with soap and hot water; they must be washed internally with a special bottle brush made specifically for baby bottles. During the 1940’s and 1950’s and even the 1960’s parents of infants would boil their glass bottles in a special sterilizer to make sure that the bottles were germ free. This method was eventually dismissed as doctors believed that good washing with soap and hot water would do the trick.

Although many people are conscientious about cleaning their reusable water bottles, I have not heard or seen that special brushes are popular to clean them thoroughly. Even though they are being washed in hot water and soap daily, the white film can be difficult to remove and even to notice. An experiment was tried by a man named Carl Behnke to find out just how clean his water bottle actually was. He ripped paper towels from the roll hanging in his kitchen and packed them into his clean looking bottle. Although the towels started out white, they became stained with the remains of something. Carl was mistaken in the slippery feeling he felt when he put his fingers in the bottle. He thought that slick sensation was how the bottle was produced but once he looked at those soiled paper towels, he realized he was wrong. This was not the manufacturer’s intent but a build-up of some type of bacteria as we will detail as we go on.

Not only was Carl curious, but he was also worried and decided to start a survey. Carl approached his friends and colleagues asking them if he could borrow their bottles for his study. Many people were pleased about lending their bottles to Carl, yet some people did not want to know what the outcome was because those who were reluctant knew by themselves that they were not cleaning their bottles properly or at all! As you can well imagine what were the results of Carl’s study, the affirmation that the bottles were full of bacteria.

How do Different Types of Reusable Water Bottles Affect Bacterial Growth?

If you live in an area where it is safe to use tap water such as New York City, it does not mean that your reusable water bottle will be safe from bacteria. Boiling your tap water before filling your bottle is not necessarily an insurance policy against bacteria forming. In Singapore a study was conducted using boiled tap water placed in bottles that were used during a whole day. Even a few hours into the morning bacteria increased to about 75,000 bacteria per milliliter and for an entire day the bacteria level increased to 1-2 million milliliter.

As expected, glass bottles win out for taste, environment, and do not react with the water inside of them. However, for convenience and mobility, plastic is certainly the winner. Since glass bottles are usually made from natural minerals such as sand, and limestone they are completely recyclable. The trouble is that glass bottles do break so if you are doing sports and other lively activities it would be smart to use your plastic alternative. If you are going to and from your office, a glass bottle would be more environmental and taste friendly.

Professionals discourage putting any sugary liquids into your bottles, glass or plastic. You may put a simple hot tea with no flavoring in your glass bottle if it is made of borosilicate (heat resistant glass).

Is it Safe to Store My Water Bottle at Room Temperature?

Absolutely not! Room temperature is the perfect breeding place for the rapid growth of bacteria. There are many folks who find it difficult to drink cold water so placing the bottle in the fridge is not their favorite option. Bacteria grow between the temperatures of 68°F and 98°F and the longer it stays at room temperature the easier it is for the bacteria to multiply.

One way to lessen the growth of the bacteria even at room temperature is to start the day out with a pristine clean bottle.

How to Clean Your Reusable Water Bottle

First, we must understand that the bacteria are not only multiplying from the water in the bottle and the water itself but from the person who is drinking from the bottle. Each time you put your lips in the bottle you are freely handing over bacteria from your mouth. There are about 500 to 600 different types of bacteria in people’s mouths at one time according to Primrose Freestone, who is a member of the clinical microbiology staff at England’s University of Leicester. She stresses that humans have the tendency to put their fingers into their mouths either just touching their lips or biting their nails. Now, unless they wash their hands ultra frequently with soap and hot water they will be introducing germs into their mouths. These germs will be transferred not only to the mouthpiece of the bottle but into the water itself. Harmful bacteria such as E. Coli are plentiful in the workplace and can cause severe upset stomach if too much is added to the gut. The stomach does have E. Coli naturally but when this same bacteria turns into pathogens then people become sick.

The best way to clean a reusable water bottle is in a dishwasher with a sanitizing cycle. This means that when looking for a reusable water bottle check the label to see if it is dishwasher safe. Alternatively, you should clean your bottle daily with hot water and soap to remove any of the slimy stuff. Buy a special bottle brush that you should use at least once a week to clean the inside and outside of the bottle. A very important component to sanitize is the cap where germs and mold tend to grow.

An additional method of disinfecting your bottle is to use a solution of three parts water to one-part regular white vinegar periodically. An alternative to this type of disinfectant would be one teaspoon bleach for a quart of water. You must rinse the bottle well to take away the taste of these disinfectants.

Do not store your water bottle unless it is absolutely one hundred percent dry. Keep your bottle on the counter when not in use open until completely dry. (It’s a good idea to have more than one personal bottle.) Keeping a closed water bottle that is not completely dry will increase the likelihood of mold and all your preventive cleaning methods will be for naught.

Final Words

Drinking water is a great alternative to sweet or diet drinks but storing water safely in reusable bottles is quite challenging. There are always bacteria and mold lurking and waiting to get into our guts and we must be diligent in keeping our reusable and sometimes expensive bottles safe from germs. Although bacteria such as E. Coli live in our stomachs regularly, extra doses of this germ get into our bodies through sloppy upkeep of our water bottles. Also, if a person is taking antibiotics for other issues, they are more susceptible to E. Coli. A good idea is to check with your doctor about adding probiotics to your regiment during the time when you are taking antibiotics. It would be a good idea to switch to using one-time water bottles until your infection dissipates.