Consider three things when picking the perfect 18- to 20-ounce water bottle: usability, durability, and temperature control
When it comes to water bottles, I’ve tested them all, from the monster 64-ounce growler to the cute li’l eight-ounce whiskey tumbler. But if I had to throw all but one away, the last bottle standing would be 18 to 20 ounces. That’s the just-right size—plenty of water for a hike or coffee for a morning jump start. I tested five leading insulated models head-to-head to pick a winner.
Usability: I weighed the bottles on a kitchen scale, drank both iced water and hot tea from them, and hand washed and dried them three times.
Thermoregulation: I tested cold retention by filling each bottle with cold water and enough ice to get the temperature settled at 60 degrees, then took the temperature again after 12 hours. I tested how long the bottles can keep drinks hot by pouring 200-degree water into each vessel and letting it sit for six hours. (For perspective, the companies in this test claim their bottles can keep drinks cold from 24 to 65 hours and keep them hot for eight to 12 hours.)
Durability: I filled each water bottle up to the brim and dropped it on its bottom five times, on the side five times, and on its lid five times, all from shoulder height.
#1. Yeti Rambler ($30)
Weight: 17 ounces
Usability: The Rambler had the widest mouth of the bunch, meaning it was the easiest to clean, ice cubes fit in with ease, and I could use my pour-over to brew coffee directly in it. It also had a wide lip, which let more air in to cool tea as I drank it so it didn’t scald my mouth.
Thermoregulation: After 12 hours, the temperature of the ice water rose one degree. And after six hours, the hot water dropped 43 degrees.
Durability: The Rambler absolutely dominated the durability test. It was the only bottle that resisted all denting.
The Takeaway: As long as you don’t mind the weight and prefer a wide-mouthed vessel, the Rambler is the clear winner in this test. I honestly was not expecting one bottle to perform so much better than the others. And Yeti products typically cost twice as much as the competition, but the Rambler’s price is right on par with (or a mere $10 more than) the others here.
#2. Hydro Flask Standard Mouth ($30)
Weight: 12 ounces
Usability: The perfectly contoured lip and smaller opening made the Hydro Flask my favorite for cool drinks (the width was just right to get a big gulp without spilling). But that relatively tight opening proved a pain to clean without a specific brush, though it did still fit a tea bag.
Thermoregulation: The cold water gained three degrees and the hot water lost 55 degrees.
Durability: The edges around the base actually compacted a bit, the lid fared the second best of the group behind the Yeti, and the sides suffered only minor scuffing.
The Takeaway: This bottle’s straightforward design is its strength. It didn’t excel in any one test but showed itself to be a reliable, durable, and enjoyable bottle, which is really all most of us are looking for.
#3. Stanley Classic Vacuum Water Bottle ($20)
Weight: 14 ounces
Usability: The lid on the Stanley was best suited to cold drinks because the spigot was easy to chug out of when I was parched. With the lid fully off, the opening was big enough to easily fill with ice and clean by hand. It wasn’t great for hot beverages, though, because tea came out of the spigot with a mild plastic taste and hot, leaving no chance to blow on it.
Thermoregulation: The cold water gained six degrees, and the hot water lost a whopping 64.
Durability: The Vacuum Water Bottle was the second most durable in the test. I thought the plastic-and-metal lid would get crushed when I dropped it, but it held up remarkably well. Though certainly scuffed, it was completely usable.
The Takeaway: Like to drink cold water out of a small spout? Here you go. The Stanley would have taken second overall save for its subpar heat and cold retention.
#4. Bear Grylls Triple Wall Vacuum Insulated ($20)
Weight: 10 ounces
Usability: The opening on this Bear Grylls model proved the perfect size for both hot and cold liquids: it wasn’t so wide that it would spill when you’re drinking on the move, yet it was wide enough to let me blow on hot coffee. The textured exterior had a nice feel and lent some extra grip. This bottle is also considerably lighter than the others on this list. The seven ounces of difference between this and the Rambler might not be apparent if you’re just drinking water at your desk, but you’ll notice it if you’re lugging coffee on a ski tour.
Thermoregulation: The cold water was four degrees warmer after 12 hours. The hot water cooled by 50 degrees after six hours.
Durability: The low weight of this bottle forces a sacrifice in durability. The lid completely broke the first time I dropped it.
The Takeaway: The Bear Grylls bottle was actually neck-and-neck with the Yeti until the durability test. I’m still excited about this relatively new brand, but the broken lid kept it out of the top three.
#5. Klean Kanteen 20-ounce ($33)
Weight: 13 ounces
Usability: The looped top on this Klean Kanteen is certainly utilitarian, but it’s not all that comfortable to hold. The lip is thin and not comfortable to drink from, which may sound nitpicky, but it was noticeable enough to be a pain. On the plus side, the thin lip makes for a wider opening, which allows easier gulping and cleaning.
Thermoregulation: The cold water was four degrees warmer at the end, and the hot water lost 56 degrees.
Durability: The stainless-steel reinforcement on the base fell off on the third drop, and the lid and sides had some dents and got a bit chewed up.
The Takeaway: It was a bummer that the Klean Kanteen took so many big hits during the drop test, because if we were scoring on temperature regulation alone, this bottle would have ranked higher.