The world's most in-depth and scientific reviews of gear

How to Choose A Water Bottle

An array of different bottle types is shown above, from glass, to coll...
Photo: Jane Jackson
By Jane Jackson ⋅ Senior Review Editor
Monday March 25, 2019
Our Editors independently research, test, and rate the best products. We only make money if you purchase a product through our links, and we never accept free products from manufacturers. Learn more

There are numerous options out there for water bottles and it can be hard to sort through these options to find the best model for your specific use. We researched all the options out there and narrowed in on the top picks from each major category.

Among the selection of water bottles we used in our Best Water Bottle Review, we saw a lot of variation. We broke down our selection into four main categories: glass, collapsible, plastic, and stainless steel. Within these classifications, we found bottles designed for specific uses — bottles for one-handed drinking, integrated filter bottles, leak-proof bottles…the list goes on.

Related: Best Water Bottle

Some of these technological developments were impressive, while others seemed to just add complexity to the simple task of drinking water. In the following article, we outline the merits of the array of materials and features found in water bottle design. Hopefully, it will help you find the right bottle to match your lifestyle and needs.

Why Buy a Reusable Water Bottle?

If you don't already think a reusable bottle is a good idea, allow us to convince you with three simple points:
  • It's better for the environment. Producing one bottle takes fewer resources and creates less pollution than the production of bottled water. Each refill saves a disposable plastic bottle from being made.
  • A reusable bottle costs less over a relatively short amount of time. If you are buying bottled water each time you could be refilling a reusable bottle with tap water, you're throwing money away.
  • Drinking from a reusable bottle is just as healthy as bottled water. With tap water being tested by local, state, and federal agencies, there is no reason to believe that it is less safe or clean than bottled water.

If our reviewers can only agree on one thing, it would be this --...
If our reviewers can only agree on one thing, it would be this -- Reusable water bottles are the way to go. Get one!
Photo: Jenna Ammerman

Things to Consider Before Buying

Before you hit the market, we recommend asking yourself a few questions first:

How will I use my water bottle?

Knowing how you plan to use your bottle will quickly narrow your field of choice. Is this bottle going to accompany you on rugged backpacking trips where you are counting the ounces of each item of gear? Or is it going to accompany you to yoga class, where you want it to look slick next to your yoga mat? Some bottles, like the Klean Kanteen Classic, are well suited for a wide variety of environments and activities. However, if you are looking for a bottle for one specific purpose, such as multi-day backpacking trips, you're going to be better served by the Hydrapak Stow. If you need a bottle for everyday use around town, the award-winning Lifefactory Classic 22 is a great choice. Identify your needs, then find a bottle that fulfills them.

Collapsible vs. Rigid

Collapsible bottles are in their prime when space is limited and weight is crucial. Unlike rigid bottles, they don't take up much space when they're empty. Just roll them up and pack them away. For this reason, they make great back-up reservoirs on multi-day hikes. Not only handy in the backcountry, but collapsible bottles are also useful when traveling. These bottles are the most awkward to use and generally present low durability.

A collapsible bottle in its element - life on the go.
A collapsible bottle in its element - life on the go.
Photo: Jane Jackson

That said, there are many distinct advantages to having a rigid bottle. We found them generally easier to drink from, as they don't flop around. In a pinch, they can double as a blunt instrument, rolling pins, hammers, or improvised waterproof canisters. Rigid bottles typically insulate better than collapsible bottles, as well. Rigid bottles, like the Nalgene Classic Wide Mouth, make great primary vessels in the backcountry.

How do I want to access my drink?

The most basic purpose of a water bottle is to transport liquids so you can stay hydrated. All the bottles transport water, but some are easier to drink from than others. "Ease of Use" is a key consideration because it includes not only drinking from the bottle but carrying it and using the lid as well. Most of this depends in the lid type: is it wide mouth bottle? A flip-cap? A bottle with a narrow mouth? We also found that the standard screw cap isn't the most convenient for those of us seeking a bottle to keep us hydrated at work and on the move. New cap designs give you some options to assist you in staying hydrated throughout the day. When drinking straight from the bottle's body, narrow mouths are easier to use, while wide mouths are handier in the backcountry. Bottles with a screw cap, straw lid, flip top, and spouts were all present in our reviews. We also had a mix of wide and narrow mouths. We broke these up into two groups for further details.

Quick Access vs. Screw Cap

Most bottle brands offer a few drinking cap options and for everyday use, we prefer quick access caps. The quick access options available range from straws to the push-pull caps offered by Platypus and Klean Kanteen. We found two advantages to these quick access cap types. First, they allow you quick, one-handed access to your liquids. Second, they actually affected how often we drank from our bottles. Being more convenient than a screw cap, the quick access cap options lead us to consume more water throughout the day. One tester reported drinking two to three times more water when using a push-pull (or sport) cap, as opposed to her screw cap. If you like drinking from your bottle, you're going to drink from your bottle more, and that's its number one function.

The CamelBak's long time solution to the one-handed drinking problem...
The CamelBak's long time solution to the one-handed drinking problem is the Eddy, which has a foldable straw.

A disadvantage of using a quick access cap is that anytime you add parts, you add potential points of failure. Additionally, caps that have exposed drinking surfaces tend to get filthy. This may not be as much of a concern in the backcountry (just a bit of trail pepper), but if you plan on using your bottle daily, expect to be sanitizing it often.

The alternative is a simple screw-on, screw-off cap. We favor these in the great outdoors because they have a smaller chance of failing when away from a water source. They are easier to clean and to keep clean than most quick access caps. We also consider these caps very unlikely to open themselves inside our packs and leak liquids on our gear.

Narrow vs. Wide Mouth

When drinking straight from the bottle's mouth, narrow mouth bottles tend to be easier to drink from. They are less likely to splash down your chest, and you can usually continue moving while drinking, too. With some exceptions, the narrower mouths still allowed room for ice cubes and did not make filling the bottle much of a hassle.

The beauty of the Hydro Flask is its simplicity. Its two parts, lid...
The beauty of the Hydro Flask is its simplicity. Its two parts, lid and body, are easy to clean, simple and sleek. The bottle is heavy, but it makes up for it in all other categories.
Photo: Eric Bissell

Wide mouth bottles are easier to clean and fill, which we find to be crucial. The biggest advantage of wide mouth bottles is their compatibility with many water filters. Most wide-mouth bottles produced today are also water filter compatible. This makes them more versatile and a good choice for gathering water from streams in the backcountry.

In general, we recommend narrow mouths for most single-day or everyday uses, and prefer wide-mouth bottles for multi-day trips where we'll need to use a water filter.

Hot and Cold - Best of Both Worlds?

If you want to switch from hot to cold beverages, or even just hot beverages, an insulated bottle is for you. The insulated bottles in our review kept hot liquids hot for 6-7 hours, and cold liquids cold for over 24 hours. They are what you need for transporting hot drinks to the office and in the outdoors in cold weather. Additionally, they shouldn't sweat when filled with cold drinks, making them great for cold juice, smoothies, and ice water anywhere you go. Keep in mind that insulated bottles are often more expensive, heavier, and bulkier, so if you don't need to maintain the temperature of your beverages for long amounts of time, you can save a good deal of money, weight, and space by sticking with non-insulated.

Insulated bottles help you get on the go with your hot or cold...
Insulated bottles help you get on the go with your hot or cold beverages.

Multiple Bottles?

We find that most bottle options are inexpensive enough to allow you the freedom of purchasing a few bottles, each with a specific purpose in mind. For example, you might want to purchase a glass or metal bottle for everyday use, yet have a plastic bottle reserved for specific outdoor rec activities. Or maybe you want an insulated bottle for your daily hot beverage and a non-insulated bottle for your athletic pursuits. It's up to you, but we feel that the modest prices of most bottles make this a real possibility, especially if you add our Best Buy winner, the Nalgene to your "quiver."

Types of Bottle Materials

Now that you've spent some thinking about what you need from a water bottle, let's finish up by diving into the types of bottle materials you can choose from. The three most common bottle materials are plastic, metal, and glass, with some variation within each classification. Each has its own list of pros and cons, as well as its best applications.

On a daily basis, we prefer drinking from bottles that allow minimal/no contact with plastic. We tend to use our plastic bottles only when truly necessary, such as a collapsible when traveling or when every ounce is crucial.


Using plastic for water bottles gives manufacturers quite a bit of versatility. Plastic bottles can be rigid or collapsible, clear or colorful. They can be formed into a great variety of shapes. One of its greatest advantages, you can argue, is that plastic is cheap to make. Although plastic bottles can withstand some knocks, they are not 100% durable. Realizing that there are many different kinds of plastics available for a company to use for their bottles, we outlined some general pros and cons below - there are exceptions to these rules, but generally, this is what we found.

  • Lightweight
  • More durable than glass
  • Often less expensive
  • Huge variety in design
  • Translucent for better water management
  • Able to freeze water inside

  • Less durable than metal
  • Uses non-renewable resources to produce

Plastic bottles are durable, versitle, and light weight. The Nalgene...
Plastic bottles are durable, versitle, and light weight. The Nalgene is a tried and true classic.

We like using plastic bottles for extended backpacking purposes the best, especially in cold weather. The collapsible models make great back-up water reservoirs that pack nicely, and the rigid bottles are insulated enough to avoid freezing inside our bags. On cold nights, nothing beats throwing a rigid plastic bottle filled with hot water into your sleeping bag for extra warmth, something you can't really do with glass or metal. Additionally, traveling through airports with a collapsible bottle is slick and easy.

BPA and Estrogenic Activity

BPA (Bisphenol A) is a plastic-hardening chemical that has been abandoned in the water bottle industry in response to scientific research indicating its health risks. Over time, common stresses like hot liquids and exposure to UV light cause the bottle to break down, causing the chemicals used in the plastic to leach into the contents (typically water) of the bottle through direct contact.

The primary concern with BPA is that this chemical has been shown to be an endocrine disrupter in animal tests (See this scholarly article or this one.) This means that once inside the body, it can mimic the natural female sex hormone by attaching to estrogen-recognizing receptors, stimulating what is commonly referred to as estrogenic activity (EA). This would create a false presence of estrogen within the body. There is a concern that in humans, this can lead to a host of potentially negative consequences in fetal and child development, as well as the reproductive system. (See this report from the National Toxicology Program for more).

Today, plastic manufacturers use alternative plastic-hardeners to avoid using BPA and proclaim that fact loudly. Every bottle in this review came with a large sticker or tag indicating that it is BPA-free. However, the potential problem of other chemicals leaching into the contents of your bottle is not fully resolved.

What about other chemicals?

Although most water bottle manufacturers no longer use BPA, the problem is that BPA is only one of hundreds (or even thousands) of chemicals used to produce plastics. Other chemicals, including plastic softeners like phthalates, have also been called out as endocrine disrupters that lead to unnatural estrogenic activity. Six phthalates are currently banned by the FDA in the US, and even more in Europe. Unfortunately, there is very little research into the health risks of these and other chemicals, including those now used in place of BPA. Consider this quote from an article in Environmental Health Perspectives (a monthly peer-reviewed journal published with support from three federal U.S. health agencies):

"The exact chemical composition of almost any commercially available plastic part is proprietary and not known. A single part may consist of 5–30 chemicals, and a plastic item containing many parts (e.g., a baby bottle) may consist of ≥ 100 chemicals, almost all of which can leach from the product, especially when stressed. Unless the selection of chemicals is carefully controlled, some of those chemicals will almost certainly have EA, and even when using all materials that initially test EA free, the stresses of manufacturing can change chemical structures or create chemical reactions to convert an EA-free chemical into one with EA." (Full article available here.)

That said, much of the scientific research surrounding EA and its effects is murky, controversial, and entangled with lawsuits.

What's being done about it?

The safety of consuming water from plastic bottles remains very controversial. The plastic industry claims that their plastics are completely safe and do not pose any health risks. According to their own research, only trace amounts of chemicals are ever leached, and these small amounts are quickly removed from the bloodstream through normal bodily processes. However, we feel that more independent research and scientific studies are necessary in order to come to this conclusion. In essence, a lack of scientific evidence does not equal proof that these chemicals are safe for humans. As pressure from the consumer market mounts, it is likely that more studies will be conducted concerning this matter.

I need something unbreakable, what do I do?

So, we're left with a complicated situation. The label BPA-free does not appear to mean that the product is free of estrogenic activity (EA), which seems to have been the very issue originally raised with regard to BPA itself. Yet, the science is murky as to what effect, if any, EA has on humans (maybe it just passes through your body harmlessly, or maybe not). So, what should you do if you want to protect yourself from potentially harmful compounds?

We think the conservative approach is to go with glass or stainless steel. Products made of glass and stainless steel are quite competitive, and in many outdoor activities the added cost, weight, and breakage risk (in the case of glass) is just not a big deal. The potential health benefits will justify a bit more weight and cost for many consumers.

That said, those who choose the weight, durability, and other noted advantages of modern plastic water bottles, can know that we've looked carefully at this issue, and we found no scientific study that definitively proves a serious health risk.

Nonetheless, if you do use a plastic water bottle, we do recommend these practices:
  • Do not heat up your bottle in the microwave.
  • Do not use your plastic bottle for the consumption of hot liquids.
  • Hand wash your plastic bottles, as opposed to tossing them in the dishwasher.
  • Avoid UV exposure, such as leaving your bottle laying in the sun.
  • Toss your bottle if the inside becomes heavily scratched, worn, or discolored.

For more practical advice on using plastics, in particular with regard to their potential impact on infants or a pregnant woman, be sure to check out this article, published by our sister site, BabyGearLab.

I want to do more research

For further research, the following articles provide more details:
Environmental Health Perspectives article
Mother Jones article
BabyGearLab's take on plastic baby bottles

More on BPA from the Endocrine Society (skip to page 58)


The metal bottles tested in our review were all made from food-grade stainless steel. Aluminum is another common option, but no aluminum bottle made the cut for our selection of finalists. Metal is an excellent conductor of heat, which is a mixed blessing for a metal bottle. On the one hand, it can serve as great emergency or spontaneous cookware. On the other, it's rubbish for hot liquids (unless insulated), and it gets too hot to use as a nighttime warmer.

If you are choosing an insulated metal bottle and want to avoid contact with plastic, make sure that your bottle does not have a plastic lining on the inside. Neither of the insulated bottles we reviewed had a plastic lining.

Speaking to their durability, the metal bottles we reviewed dented during our drop tests, which affected their aesthetic properties. However, all the steel bodies survived their falls onto a hard surface. We found that metal will bend, rather than break. That said, a bottle is only as strong as its weakest point. Case in point, the metal body of the Hydro Flask Insulated survived our drop tests, but its plastic cap did not.

  • Most durable material, and therefore most reliable
  • Generally accepted as posing no health risks
  • Lighter than glass
  • Can double as a cooking vessel in a pinch
  • Metal components are dishwasher safe (excluding vacuum insulated bottles)

  • Slightly heavier than plastic
  • impart metallic taste
  • Prone to dents

The Contigo Thermalock is a lightweight option that is still metal...
The Contigo Thermalock is a lightweight option that is still metal and vacuum insulated.
Photo: Jane Jackson

Several years ago, we would not have called metal water bottles "versatile," largely due to their weight and awkwardness. Today, we enjoy using our metal bottles at work, at the gym, and for most outdoor recreational activities. The insulated options are great at keeping our liquids hot or cold in the office and outdoors, regardless of the external temperature. We love using the non-insulated Klean Kanteen Classic as a do-it-all bottle, as it is easy to use, lightweight, and durable. As the technology for metal bottles improves, so does their functionality and versatility.


We think that the drinking experience from glass bottles is the best. There is just something about glass that makes water taste purer, fresher, all-around better. Also, glass is widely accepted as a safe alternative to plastic containers.

The glass bottles in our review incorporated a silicone sleeve into their designs to increase their durability, which proved effective in our drop tests. When impacted on the silicone sleeves, all the bottles survived their respective falls. However, the bottles we tested had large areas of bare glass. An impact on these areas with a hard, pointed surface would most likely break the body.

  • Generally accepted as posing no health risks
  • Tastes great
  • Transparency allows for easy management of water consumption
  • Glass components are dishwasher safe

  • Heaviest material
  • Fragile
  • Cannot use with extreme temperatures (no boiling water, cannot use to freeze water)

Though the Purifyou is shown here next to a crash pad, we felt that...
Though the Purifyou is shown here next to a crash pad, we felt that it was a little to heavy and fragile to want to bring bouldering or hiking. Instead, we typically used this bottle in an urban setting.
Photo: Jane Jackson

If you want a bottle that doesn't impact the taste of your water and want to avoid using plastic, glass is your best option. We found that the Lifefactory and Purifyou Premium are excellent choices for consumers seeking a bottle for home and the office. Great in terms of eco-health, glass bottles are also becoming more durable, and therefore more useful than even we initially expected.

Below, we have links to some of our other hydration reviews. If you have read this far and realized that perhaps a bottle is not the right vessel for you, perhaps a hydration pack or bladder is more suitable to your specific needs. For fast-moving activities, like trail running or mountain biking, a hydration pack can be useful, reducing the amount of time spent stopping and drinking water. Read on to learn more about bladders and packs designed for these specific uses.

Hydration Alternatives and Accessories

Hydration Bladders
CamelBak Antidote Reservoir
The advantages of a hydration bladder like the Geigerrig Hydration Engine include hands-free usage and larger volumes. The bladder, a collapsible reservoir ranging from one to several liters in volume, is attached to a hose that you suck on to draw water into your mouth. On long hikes, these are easier to use for hydration than a water bottle that you have to dig out of your pack each time you need a drink. Most backpacks made today come equipped with a hole for the hydration tube, and some even have a special compartment for a bladder. The downside to hydration bladders is that they are less durable, have shorter lifespans, and are harder to clean (than bottles). And in the office, we recommend a bottle over a bladder.

Hydration Packs

Camelbak M.U.L.E.
These are great when you don't want to carry your entire backpack on your full-day hike or bike ride, yet still need to stay hydrated throughout the day. Hydration packs like the CamelBak M.U.L.E. are usually lighter than most backpacks and have proper ventilation, making them more comfortable on long days. They make drinking on the move a breeze, and their convenience helps you to stay fully hydrated. Most also feature pockets for storing additional items such as food, first aid kits, and tools. Like hydration bladders, they also are harder to clean and have shorter life spans than bottles. It's also harder to ration your water with these packs. Lastly, hydration packs cost significantly more than bottles.

Running Hydration Packs

These are designed to stay in place as your body moves while running. They often incorporate a vest design to achieve this feat and have pockets for storing food, electrolytes, and blister supplies, as well as a phone or GPS. See our complete running pack review.

Mountain Bike Hydration Packs

These packs are a great investment if you like long biking sessions. Not only do they transport large volumes of water to keep you hydrated, but they also have space for food, essential tools, and sometimes even rain gear.

  • Share this article: