How to Choose a Water Bottle

By T.D. Wood, REI Expert Advice Editor

When selecting a water bottle, your choice may be influenced by some of the following factors:

Materials

Materials affect a bottle's durability, weight, appearance and odor resistance. Options include:

Copolyester (Common Brand Name: Tritan®)

Essentially, this material is the "new polycarbonate." Like polycarbonate (discussed below), it is light, tough, translucent and very durable—just not as invincibly shatterproof. Unlike polycarbonate, it does not contain bisphenol A (BPA). Well suited for challenging outdoor conditions.

Temperature range: -211°F to 275°F (-135°C to 135°C).
To identify: Bottle may be clear, colored, frosted or feature artwork. Rigid construction.
Recycling number: None or No. 7.
PROS: Low weight; durable; retains few, if any, odors if used to transport flavored liquids; easy to view contents (if clear or colored). BPA-free.
CONS: May crack or break if dropped from some height on very sharp, hard, or ragged surfaces.

High-Density Polyethylene (HDPE)

A semi-rigid plastic used in milk jugs and some water containers. Appropriate for outdoor pursuits such as hiking and backpacking.

Temperature range: -148°F to 248°F (-100°C to 120°C).
To identify: Traditionally, HDPE is often a cloudy white color; colored versions are available. Exterior is firm yet slightly pliable.
Recycling number: No. 2.
PROS: Low weight; durable. Bottle's content level is viewable. Less expensive than copolyester or polycarbonate. BPA-free.
CONS: With force, could be punctured. May retain or convey some odors or tastes.

Low-Density Polyethylene (LDPE)

A more flexible version of polyethylene commonly used in squeezable water bottles, hydration reservoirs and some collapsible water containers. Popular with cyclists and day hikers.

Temperature range: -148°F to 180°F (-100°C to 82°C). Manufacturer opinions vary on LDPE's suitability for use in microwaves. Use caution.
To identify: Opaque; available in many colors; squeezable.
Recycling number: No. 4.
PROS: Low weight; durable; flexible; less expensive. BPA-free.
CONS: Susceptible to punctures. Could melt if too close to a fire. May retain or convey some odors or tastes (though some manufacturers use proprietary techniques to negate odor- and taste-transfer concerns).

Aluminum

Lightweight, rugged material. Appropriate for most outdoor pursuits. Models made by SIGG use a proprietary bottle lining that resists tastes and odors. SIGG does not identify the composition of the proprietary lining, claiming only that it is "independently tested to be taste- and scent-inert—and resistant to any leaching (0.0%) so [it is] 100% safe."

Temperature range: Not recommended for freezing or for accepting boiling water. Not for use in microwave ovens.
To identify: Lightweight metal; often in a narrow profile; available in many colors.
PROS: Low weight; very durable; retains few, if any, odors or tastes. Some models offer interesting exterior art.
CONS: Can dent (though without damaging lining in most cases). Transfers temperature of contents to its exterior.
Notes: Hand-washing is recommended due to narrow shape. Dishwasher use does no damage other than causing exterior to fade. SIGG recommends consumption of fruit juices within 12 hours to prevent fermenting.

Stainless Steel

Tough, durable material. Stylish exterior. Most commonly used for day trips or urban use.

Temperature range: Not recommended for freezing or for accepting boiling water. (For hot beverages, choose a vacuum bottle, which is an insulated stainless-steel container.) The maker of the Klean Kanteen product line advises: "Warm beverages can be used at personal comfort level." Not for use in microwave ovens.
To identify: Silvery, metallic exterior; slight hefty feel.
PROS: Very durable; retains few, if any, odors or tastes. Suitable for acidic beverages.
CONS: A touch heavy. Can dent if forcefully struck. Most models transfer temperature of contents to their exteriors.

Polycarbonate (Common Brand Name: Lexan®)

Due to the concerns recently voiced by many REI customers, REI no longer offers (as of April 19, 2008) polycarbonate water bottles. Polycarbonate is a tough, translucent plastic that includes bisphenol A (BPA). Ongoing scientific debate about the appropriateness of polycarbonate for beverage containers has resulted in REI offering many BPA-free water bottle alternatives (described above), which have replaced the demand for polycarbonate.

If you're wondering if any of your existing water bottles are made from polycarbonate, here are some clues:

To identify: Bottles may be clear, colored or frosted. Rigid construction.
Recycling number: None or No. 7. (Note: In recycling, No. 7 is a catch-all category for plastics still awaiting a broadly accepted recycling technology. Until one is achieved, most recyclers discard No. 7 items.)

Cleaning of Bottles Listed Above

Follow manufacturer recommendations for dishwasher use. Many manufacturers of the styles described above claim their products are dishwasher-safe (if placed on the top rack). Yet hand-cleaning (and thorough drying) is often recommended for the most effective results.

Hydration Reservoirs

Nearly every brand of reservoir will claim some sort of proprietary composition. Reservoirs are very flexible; all are BPA-free. BPA's chief attribute is its ability to create a very hard, rigid version of plastic.

Some reservoirs are quite sophisticated in their efforts to combine durability, taste-free environments and safe materials. One model bonds a tough polyethylene exterior to two super-thin liner layers that put the water in contact with metallocene LLDPE, an "ultralow" version of low-density polyethylene (LDPE) and a high-grade material used in food packaging. Many reservoirs use a food-grade polyurethane as a liner, another good material.

Any reservoir and sip tube should be emptied immediately when a trip is complete and be allowed to air out and dry. The crew at Cascade Designs (maker of Platypus and MSR Dromedary, Hydromedary and Cloudliner reservoirs) offers the following tip for keeping reservoirs and tubing fresh and taste-free:

Mix 1 or 2 cups of baking soda with 2 or 3 quarts of water. Squeeze half a lemon into that mixture, pour it into a reservoir and let it sit for 1 or 2 days. Empty the reservoir, rinse it very well and arrange it so it can dry fully.

Some of that mixture can also be used to soak a sip tube to restore its freshness. Another option: Soak the tube in a mild bleach solution. Again, rinse and dry thoroughly. Ensuring that a reservoir dries completely is important.

Design

While some arty exceptions exist, most water bottles offer a cylindrical shape so the bottles slide smoothly into side pockets on packs. Smaller cycling bottles are sized to fit frame cages.

The chief variant in bottle design is the size of the opening. Which is best? Let your personal preferences be your guide. Basically, you will choose either a wide opening that accommodates a big gusher of a flow rate or a restricted opening that minimizes your risk of spills.

Wide Mouth

Very popular. Many offer a 63mm opening, a width that:

fills quickly and easily;
most closely mimics a standard drinking glass, proving a high flow rate;
easily accommodates ice cubes;
matches the threads found on many water filters so you can forge a no-spill, filter-to-bottle connection while pumped water flows through the filter. It's a nice feature.

Narrow Mouth

If tipped, contents don't flood out of the bottle so rapidly. Some backcountry gourmets find narrow mouths allow them to more easily control a bottle's pour rate. (Optional pour spouts are also available for some bottles.)

Push-Pull Valve

Commonly found on cycling bottles; also used on larger bottles. Pull to open, push to close. Some people love this valve's spill protection; others weary of the pulling and pushing. However, if you remember to close the valve, water won't spill if the bottle is tipped.

Bite Valve

Often attached to a straw-styled tube that sits inside the bottle. Same bite-to-drink methodology as found on many hydration systems, which to some is an acquired taste. Valve automatically closes after each use, so a tipped bottle causes no spills.

Volume

Many water bottles are quart-sized (32 fluid ounces). This standard volume simplifies the treatment of backcountry water. One chlorine dioxide tablet, for instance, is recommended for disinfecting a quart of water; the Steri-PEN is programmed to work best with 16 or 32 fl. oz. of water. Other bottle sizes exist, primarily for the sake of a distinctive look.

A quart of water weighs a touch more than 2 pounds. You can choose a smaller bottle to save weight. Just know your route well enough so you don't run out of water during a long ridge walk or other prolonged dry stretch.

Large-Volume Containers

Most, if not all, large storage containers (3 quarts and larger) are constructed with BPA-free polyethylene. Some have rigid sides and are designed for campground use. Foldable models can hold a couple of gallons yet weigh just a few ounces, making them suitable for multiday backcountry use where a base camp will be established.

Extras

Arty designs are cool, though pragmatic types may find bottles with markings such as measuring indicators (4, 8, 12, 16 fl. oz.) are more useful.
Add a belt bottle holster to a bottle within easy reach.
Fabric bottle insulators can extend the desired temperature of the liquid in your bottle.
Bottles (or reservoirs) with openings that are compatible with a filter you own are very handy. The standard width is 63mm.

A Parting Thought

A 2007 New York Times article reported that Americans consume more than 30 billion single-serving bottles of water annually. (Wow.) The nonprofit Consumer Recycling Institute estimates at least half, and probably closer to 75%, of these bottles turn into waste. That means they wind up in landfills, get incinerated or turn into litter. (Double wow.)

Those figures do not take into account the materials (petroleum being chief among them), production costs and transportation costs associated with plastic bottles. It all provides more incentive to find a reusable water bottle to carry with you on and off the trail.