Plastic Water Bottles May Harbor More Bacteria, Experts Say

Drinking enough water daily is essential for supporting your physical activity, aiding brain function, improving digestion and benefiting your skin. The best way to make sure you have enough to sip on is with a reusable water bottle. Take it on the run or leave it next to your bedside table—these nifty tumblers have an essential place in our routines, which is exactly why you should have the right one on hand, and keep it clean. 

Biofilm, a slimy, slick residue that forms within your water bottles, harbors harmful bacteria that can leach into your water, according to Kali Kniel, a microbiologist and food safety professor at University of Delaware. Studies have shown that plastic water bottles are likely to develop this film more quickly than stainless steel or glass alternatives. Those pesky plastic bottles also release more microplastics than other options on the market, adding even more potential fuel to the fire. Kniel recommends washing your reusable bottles every two to three days, and it pays to choose the right one. We’ve gathered a few options below to shop, including different materials and designs to best suit your needs for healthy water drinking all day long.   

Stainless Steel and Glass Water Bottles 

W&P Porter Glass Water Bottle with Protective Silicone Sleeve

While stainless steel proved to be the better option in terms of bacterial growth, according to the study, I have to share this glass bottle, which is another material that’s recommended by experts. My partner and I got this bottle to take on the go because of how simple it is to use and clean, which is another key element to preventing biofilm. The top is simple to clean, and with a cleaning brush, it’s easy to get inside. Plus, the bottle is made entirely of glass and silicone—a healthier swap for plastic. 

Hydro Flask Stainless Steel Micro Hydro

This is my current go-to water bottle. I received the Micro Hydro in the mail to try from the brand, and I absolutely love it. A strikingly tiny 6.7-ounce bottle, I take this to the gym, on walks and while on errands where I don’t need a ton of water but I want something to quench my thirst. It’s lightweight, fits in pockets, and is easy to hold by the handle. I can also tie it to my weighted vest for a hands-free option. Its stainless steel interior is easy to keep clean. The lid has an inner rim that can be cleaned with a straw cleaner or a thinner sponge. 

Yeti Rambler Stainless Steel Bottle

I have a few Yeti products, including this bottle. This is a straightforward, predominantly stainless steel water bottle that gets the job done. The insulation is effective, keeping ice solid for hours at a time. I prefer the chug cap because it’s easy to sip from and is less fussy for cleaning. While the top is plastic, I think having your water in the stainless steel bottle is a great option compared to an all-plastic version. 

Hydro Flask Stainless Steel Travel Tumbler with Handle

The straw on this tumbler is silicone and the body is stainless steel, helping to reduce microplastics in your beverage. The interior is in line with Kniel’s recommendation. While there are more nooks and crannies to clean, a flexible straw like this one is easy to clean with a straw brush. It comes with a handle for easy carrying when it’s filled with water. 

Owala FreeSip Insulated Stainless Steel Water Bottle with Straw

Nearly all of my coworkers rave about the Owala bottle because it helps them easily maintain their water intake. The FreeSip lid opens with the click of a button for seamless drinking. I’d say this is the best option if you’re just looking for a straightforward, effective and cute stainless steel bottle. There are dozens of color options to choose from, so you can pick what feels most like you. 

BrüMate Era 40-Ounce Stainless Steel Tumbler with Handle and Straw

The BrüMate Era tumbler takes the microbiologist-preferred design to the next level. Both the interior and the straw are stainless steel — a great option to help ward off biofilm. Despite the straw, it’s leakproof, meaning you can rely on this tumbler throughout your day without worrying about losing a drop.