So you want an insulated water bottle, but where to begin? In the last few years, the market has seen an absolute explosion in insulated water bottles, both from familiar manufacturers and new brands previously unheard of. In a world where innovations like digitally enhanced “smart” bottles and even self-filling water bottles are poised to change how we think about the humble water bottle, already we are demanding much more from our water bottles than we ever have before.
One of the demands water bottle manufacturers have best been able to satisfy is the need for insulation. Insulated bottles keep their contents hot or cold by limiting heat transfer between the bottle’s contents and the atmosphere outside the bottle. With a bit of clever engineering behind it, well-made insulated bottles are capable of keeping ice frozen even in the most blazing heat for hours on end or keeping your soup or hot coco warm inside even if immersed in snow.
We put together this article to help you find the best insulated bottle your money can buy. If you aren’t necessarily after an insulated bottle, hop over to our feature Best Water Bottles of 2016 to see what other types of bottle are out there. We’ve included some insulated options on that list as well.
Finding the Best Insulated Bottle For Your Needs
In this article, we’ll first explore a little bit about how the type of insulation, how the best insulated bottles work their magic, and then take a look at some specific brands and models to weigh in a little bit on the best purchasing decisions.
First, we’ll take a look at our Top 5 Picks with a quick comparison chart. Below that we’ll look in-depth at what makes an insulated water bottle work, and then examine our top 5 picks as well as an additional contender in-depth. Let’s dive in!
Top 5 Insulated Water Bottles Comparison
Types of Insulated Water Bottles
In the world of water bottles, the word “insulated” tends to get thrown around quite a lot, enough to confuse people about just what it means. The word “insulation” technically refers to any material which helps prevent heat loss or transfer, so by this very liberal definition, every water bottle has some form of insulation. But that is not really what you are looking for if you want the kind of insulation that will keep your smoothie frosty on a hot day.
The confusion doesn’t end here: you might also come across references to things like “insulating sleeves” or similar terms. These do provide some degree of limited insulation, but again, are hardly the type of full-blown insulated bottle which will be the primary focus of this article.
The best type of insulation when it comes to water bottles is inarguably Double-Walled Vacuum Insulation. This is the technology behind the original Thermos, and has recently been put to great use by modern companies such as Hydro Flask and Klean Kanteen to produce a wealth of well-insulated water bottles. Actually quite an old technology, double-walled vacuum insulation was invented in 1892 by James Dewar and has been in use for over a hundred years, commonly referred to as a “vacuum flask” or “Dewar flask.” Under this name, the technology has found itself employed in a huge range of applications in science in industry.
Double-Walled Vacuum Insulation 101
As long and fancy as the name might sound, the concept behind vacuum insulation is remarkably simple. The “double-walled” part of the title gives away the whole design. Vacuum flasks achieve their insulation by using two walls with a tiny gap of evacuated air (or vacuum) between them. This means that, in a double-walled vacuum insulated water bottle, you get a kind of “bottle in a bottle” effect, where the container which your liquids contact is itself enclosed.
Why does this keep things hot or cold? The important thing to consider is heat transfer. Inside a vacuum flask, the contents of the bottle have almost nowhere to transfer heat to. Since there is a gap of vacuum between the two walls in the bottle, there is hardly any air or other material to absorb and transfer the heat inside the bottle. This means that the contents – be they hot or cold – stay more or less the temperature at which they were put inside the bottle.
Check out this super helpful diagram from Thermos explaining how double-walled vacuum insulation works.
Double-Wall Vacuum Insulated Water Bottle Brands
Now that we have some idea of how it works, which specific brands of bottle accomplish this the best? All of the bottles employing this technology on the market are made from stainless steel, which certainly takes the materials question off the table. It is important to remember that as this is something of a standardized design, there are often more similarities than differences between these products.
If insulation capability alone is your only deciding factor, you might find choosing quite difficult. This is because among these types of insulated water bottles, insulation is often virtually identical from bottle to bottle. We proved this to ourselves during our evaluation of bottles for this list (more on that below.)
Putting Insulation to the Test
To figure out which bottles provide the best insulation, we rounded up our favorite double-walled vacuum insulated stainless steel water bottles and put them to the test. Each bottle was filled with 40 degree Fahrenheit water with ice chunks and left out to stand undisturbed on my countertop for 24 hours. Room temperature was not controlled during this time and fluctuated somewhere between 65-80 degrees over the course of 24 hours. How did our bottles fair?
Insulation Test: Cold
- 1. 12 Ounce Klean Kanteen: 46 Degrees F, +6
- 2. 40 Ounce Hydro Flask: 48 Degrees F, +8
- 3. 17 Ounce Cayman Fitness: 51 Degrees F, +11
- 4. 35 Ounce FNova: 51 Degrees F, +11
As you can see pretty clearly from these numbers, there is very little difference. Even after 24 hours, each bottle still kept its contents quite cold even after a full day. However, the Klean Kanteen succeeded the best at maintaining its insulation, though it is important to note that it was also the smallest capacity bottle used in the test, which may have something to do with it.
Curious about the bottle’s abilities to keep their contents warm, we repeated the same test, this time with 150 degree water. This time we only left the bottles to sit for 12 hours instead of 24, trying to stick to the “hot for 12 hours, cold for 24” advertising promoted by most insulated bottle makers.
Insulation Test: Heat
- 1. 40 Ounce Hydro Flask: 98 Degrees F, -52
- 2. 12 Ounce Klean Kanteen: 95 Degrees F, -55
- 3. 17 Ounce Cayman Fitness: 95 Degrees F, -55
- 4. 35 Ounce FNova: 92 Degrees F, -58
Once again, it was a very close race. This test really demonstrated that these bottles are much more capable of keeping their contents cold than they are warm, however they performed pretty admirably at both tasks.
We only had four bottles on hand to perform this test with, but we hope to be able to bring you a more in-depth test like this one in the future.
Our Top Picks
Below we’ll take a closer look at the four insulated bottles we used in our insulation test. In addition to the four insulated bottles we tested, we felt we had to include a few other insulated options as well. Unfortunately, we didn’t have access to a few of these models during testing, but we have owned them at one time or another and have first hand experience owning them. While we couldn’t include them in our test above, we felt it would be disingenuous to call this article the “Best Insulated Bottles” without mentioning these contenders as well!
Let’s have a look!
UPDATE: In mid-2016 Hydro Flask introduced the latest generation of their wide mouth bottles, featuring a new innovation known as the Flex Cap. Incorporating their new Honey Comb Insulation Technology into the lid, the Flex Cap Hydro Flasks offer improved insulation over the classic Hydro Flask which we used in these tests. The new cap not only offers improved insulation, but also a handy carrying strap! These new Hydro Flasks also have a range of new colors to select from. Check out the Flex Cap Wide Mouth Hydro Flask on Amazon and be sure to read our review of the Flex Cap.
The Hydro Flask still remains, day in and day out, my go-to selection for an insulated stainless steel water bottle. It has some of the best insulation I have ever come across, and in my practical experience it always seemed to be the best insulated bottle I’d ever used. This is despite also having extensively used a Klean Kanteen, which as we seen in the results above, actually proved a little more effective at insulating in the cold water test.
Regardless, the difference is almost negligible. The Hydro Flask has a stylish look, is available in a huge range of colors and sizes, and is accompanied by a wealth of accessories which allow the bottle to be customized in all sorts of different ways. They are virtually indestructible through normal use and brilliantly well designed and constructed.
In our feature “Hydro Flask vs. Klean Kanteen: The Great Insulated Debate” we tried to settle the score once and for all between Hydro Flask and Klean Kanteen, yet here we are once more forced to pit them against one another. The insulation test above actually crowned Klean Kanteen the victor in the cold test, yet strangely Hydro Flask prevailed in the hot test.
The Klean Kanteen has definitely earned its place as one of the top insulated bottles on the market. They are incredibly durable – so much so that rugged campers have even demonstrated the ability to boil water in them with no harm to the Klean Kanteen. As far as insulation capabilities go, it is definitely one of the best insulated bottles on the market. Klean Kanteens are available in just about every size, and there are a huge number of colors and artwork available.
Compared to the two insulated bottles above, this Cayman Fitness Premium Water Bottle is from a relatively unknown brand. However, it is a very well designed bottle geared towards ease of portability and usage while on the go. It fits easily into just about any cupholder, providers a brilliant leak-proofing which lets you carry the bottle without fear of a spill, and has a simple yet stylish look.
And as our insulation test proved, it is also a contender capable of stacking up to the market leaders when it comes to keeping colds cold and hots hot. The Cayman Fitness bottle does not benefit from the wide variety of options offered by Hydro Flask and Klean Kanteen, instead having only a single 17 ounce bottle. However, we have found it to be an exceptional bottle, so perhaps no variations are necessary. The only complaint we can lodge against the Cayman Fitness insulated bottle is its lack of a wide-mouth option and a very narrow mouth, which can make putting ice in very difficult.
Learn more in our complete review of the Cayman Fitness Insulated Water Bottle or visit the Amazon listing.
The FNova Insulated Stainless Steel Bottle is among a growing trend of products which are, in form and in function, essentially generic Hydro Flasks. As we have recently been discovering here at Hydration Anywhere, this appears to be a great trend for consumers. The FNova bottle is a great example of how that can take shape. Offering exceptional value for the money, the 35 ounce FNova is comparable to a Hydro Flask in almost every way yet almost $10 cheaper than a comparable 32 ounce Hydro Flask.
The FNova isn’t quite as well-built as a Hydro Flask, and as we seen in the insulation test it performs slightly below the Hydro Flask’s insulating capabilities. Regardless, it offers an exceptional value for the money, especially when the inclusion of three different lids (a screw on “sport cap” with carabiner, a very useful straw lid, and a stylish stainless steel with bamboo top cap,) the FNova is a real bargain and exceptional quality considering the price.
Learn more in our complete review of the FNova Insulated Stainless Steel Water Bottle or visit the Amazon listing.
The Fifty/Fifty Vacuum Insulated Water Bottle is the first example of one of the bottles we would have liked to have been able to include in the insulation test, but unfortunately we are no longer in possession of any Fifty/Fifty bottles, at least not at the moment. That could definitely change in the future, because Fifty/Fifty bottles have always been among our favorites for everyone involved with Hydration Anywhere, featuring a bargain price for quality insulation and a well-constructed bottle.
Fifty/Fifty offers exceptional insulation and is undeniably one of the most durable bottles on the market. Solidly constructed, no-nonsense design, highly functional insulation, and a huge range of sizes and colors, Fifty/Fifty brings everything to the table and is definitely one of the top options for insulated stainless steel bottles.
Learn more by visiting the Fifty/Fifty Water Bottle Amazon listing.
While I’ve never thought of a Thermos as a “water bottle” per-se, it turns out that Thermos actually does make water bottles. Not only that, your average Thermos is renown for being an insulated bottle, even if we might more commonly associate them with holding soup than water, they are really just as capable of doing the insulating job as any other insulated stainless steel bottle.
But if you want an actual, sleek, modern water bottle, the Thermos has you covered for that, too. This bottle has a very stylish look and performs admirably at keeping the contents more or less the exact temperature at which you put them in.
So Many Bottles, So Little Time!
In my opinion, and in the opinion of everyone here at Hydration Anywhere, the best insulated bottles around are either Hydro Flasks or Klean Kanteens. But we respect the fact that this is a subjective opinion, and more than that, there are now so many dozens upon dozens of insulated bottles on the market from so many different manufacturers that trying them all is almost impossible.
We feel confident that anyone looking for an insulated bottle would be happy with any of the selections we’ve pointed out in this article. Take some time to select the bottle which best suits your needs and everyday lifestyle. Think about where the bottle will be accompanying you, if you want it to fit into a cup holder, how much water you really need to be carrying around, how much you drink in a day, and other considerations to help guide you towards selecting the best option.
What’s YOUR Pick For Best Insulated Bottle?
Did we miss your favorite brand or model on this list? Have a suggestion for something completely different? We’d love to hear from you in the comments below! Or if you didn’t find what you were looking for in this list, check out Best Water Bottles 2016 or even Best Water Bottles 2015 to get some more ideas. If you’re sure you want quality insulation but were hoping for something a little bigger than the options on this list, read our article on the Best Insulated Growlers!
We are nowhere near done reviewing insulated bottles! Keep reading for the latest on new bottles. Check back to our Reviews Section, or signup for our newsletter to get regular updates on what’s up at Hydration Anywhere. You can also follow us on Facebook, Twitter, or Pinterest to keep track of what we’re up to. Thanks for reading!
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We explain the best type of insulation, and examine the best brands and models of insulated water bottle.