Metal or plastic? The short answer: it depends on what you’re using it for. To help you decide which bottle to buy as you gear up for summer, I put each to a rigorous test. Here are the results.
For products, I chose a 32-ounce, wide-mouth plastic Nalgene and pitted it against a 32-ounce, wide-mouth, double-walled, vacuum-insulated stainless-steel Hydro Flask*. Then I tested four critical characteristics.
Weight: I weighed each empty bottle on my kitchen scale.
Thermoregulation: I filled each bottle with 7.2 ounces of ice (ten cubes), added 54-degree tap water, and let them sit in my 72-degree kitchen for four hours. Afterward, I measured the water temperature with a meat thermometer.
Usability: I spent days chugging water out of each.
Durability: I wanted to recreate realistic scenarios, so I filled each bottle with water, then dropped them onto concrete five times from shoulder height—a test only one survived (read on for results). I knocked the remaining bottle off the roof of my car five times onto concrete. Finally, I climbed to the roof of my house and chucked the remaining bottle 25 feet into the air five different times, making sure it landed on the lid at least twice.
Hydro Flask 32-Ounce Wide Mouth ($40)
Weight: 21 ounces
Temperature After Four Hours: 38 degrees—the temperature of beer from a cold tap.
Usability: Wide-mouth bottles are easy to clean but hard to drink from while moving, for obvious reasons. I liked the exterior powder coating, which made the bottle easy to grip even when wet, and the lid—durable and easy to work one-handed—is the best one Hydro Flask has ever made. The flexible silicone carry ring didn’t beat up my fingers.
Durability: It survived the drop and throw tests and sustained only two inch-long dents at its base, plus a few dozen cosmetic scratches. The lid was scratched as well. Overall, though, it was still a fully functional water bottle.
Nalgene 32-Ounce Wide Mouth ($15)
Weight: 6.3 ounces
Temperature After Four Hours: 57 degrees
Usability: Like the Hydro Flask, this wide-mouth bottle is easy to clean and easy to drink from, as long as you’re not moving. I liked the translucent plastic because I could see how much water was left and ensure all the grime was out of the bottom after washing. I’ve long loved the textured Nalgene tops that you can open with one hand.
Durability: The bottom of the Nalgene shattered on impact after the first drop from shoulder height, which was a surprise. I’ve used Nalgene bottles for years and never had one break.
The Hydro Flask won in a major way when it came to durability and thermoregulation, but the Nalgene still stands out when it comes to weight and price. You’ll have to decide how much you want to spend and think about which factors matter most to you. On long backcountry ski and backpacking trips, I’m still going to use a Nalgene: I’d rather cut weight and lose durability. However, if I’m on a river trip through the Grand Canyon, where gravity does all work, I’d much rather bring a Hydro Flask to keep my water (or gin) cool and to protect against rock smashes.