Product Reviews

Top 5 Best Vacuum Bottles and Thermos Flasks for Hiking and Backpacking

ParagonTrails presents our comprehensive guide on the top five best thermos flasks and vacuum bottles on the market today for hiking and backpacking.

When you’re out on the trail it’s nice to have hot tea or coffee to boost your energy, but it’s irritating when you have to stop to boil water all the time. This is where having a thermos flask helps immensely. So, what’re some of the best thermos flasks or vacuum bottles on the market today for hiking and backpacking?

Top 5 Best Vacuum Bottles and Thermos Flasks for Hiking and Backpacking

  • 5. Thermos King Vacuum Insulated Bottle Flask
    • Price: ~$23.00 – $45.00 USD (Stainless Exterior vs Army Green)
    • Weight: 1.45 lbs (0.658 kg)
    • Volume: 50.0 oz (1.14 Liters)
    • Heat Temp. Duration: 24 Hours
    • Cold Temp. Duration: 24 Hours
    • Pros: Excellent hot and cold temperature retention, stainless steel interior and exterior, and twist and pour lid with top lid cup.
    • Cons: Cup lid can sometimes become too hot to hold when containing very hot liquid for long periods of time.
  • 4. Hydro Flask Vacuum Insulated Bottle Flask
    • Price: ~$47.95 – $50.00 USD
    • Weight: 1.1 lbs (0.50 kg)
    • Volume: 40 oz (1.14 Liters)
    • Heat Temp. Duration: 6 Hours
    • Cold Temp. Duration: 24 Hours
    • Pros: Very popular, and highly rated vacuum bottle with great cold temperature retention, an excellent weight to volume ratio, and a convenient loop for carabiner pack storage.
    • Cons: Low hot temperature retention, but this bottle’s well suited for resupplies of hot water every 4 to 6 hours. This time frame does work well for lunch, dinner, or rest breaks as well.
  • 3. Stanley Classic Vacuum Insulated Bottle Flask
    • Price: ~$50.00 USD
    • Weight: 2.5 lbs (1.13 kg)
    • Volume: 67 oz (1.9 Liters)
    • Hot Temp. Duration: 32 Hours
    • Cold Temp. Duration: 32 Hours
    • Iced Temp. Duration: 160 Hours
    • Pros: Incredible durability, lifetime manufacturer’s warranty, multi-functional cup pour lid, and strong handle can be used to tie the flask to your pack or can be used for easy carrying.
    • Cons: Very heavy, but definitely makes up for it in exceptional durability, and extreme temperature retention duration!
  • 2. GSI Outdoors Vacuum Bottle
    • Price: ~$35.00 USD
    • Weight: 0.813 lbs (0.37 kg)
    • Volume: 33 oz (0.94 Liters)
    • Heat Temp. Duration: 18 Hours
    • Cold Temp. Duration: 32 Hours
    • Pros: Exceptionally efficient design with one of the lowest weight per volume ratios available on the market, convenient loop for carrying with carabiner, roughly 1 day’s worth of heat retention, and 1.5 days of cold temperature retention.
    • Cons: Potential for denting due to more advanced thin vacuum design, but still very durable and remarkably lightweight.
  • 1. Klean Kanteen Classic Double Wall Vacuum Insulated Bottle
    • Price: ~$54.55 USD
    • Weight: 1.7 lbs (0.77 kg)
    • Volume: 64 oz (1.82 Liters)
    • Heat Temp. Duration: 30 Hours
    • Cold Temp. Duration: 50 Hours
    • Iced Temp. Duration: 100 Hours
    • Pros: Unparalleled vacuum bottle technology with a 1.5 days of hot temperature retention, over 2 days of cold temperature retention, and capable of retaining icy temperatures for up to 4 days.
    • Cons: Since these are so popular right now, finding these bottles when they’re in stock can be tricky due to the high demand of the 64 ounce bottles, especially in the Stainless Steel unpainted variety.


A vacuum bottle or thermos flask weighs about 1 – 2 lbs (0.45 – 0.91kg) on average, which is about the same weight as an umbrella. However, deflecting water with an umbrella is easy, but carrying water is a completely different story since water is so incredibly heavy.

To emphasize, one liter of water weighs one kilogram, and four liters of water equals one gallon. So, one gallon of water weighs four kilograms, or almost nine pounds!

Subsequently, a half gallon (64oz, 1.8L) thermos flask, one of the largest bottles on the market filled to the brim with water, weighs about five or six pounds (~2.3 – 2.7 kg) including the bottle’s weight.

This consumes somewhere in the order of around ten to fifteen percent of someone’s total carrying weight capacity, or an even a greater percentage if they have a smaller framed body.

The general rule of thumb though for weight is to carry around twenty percent of your body weight at the very most, but you also need to drink approximately 10 to 24 ounces of water per hour, or about a quarter to three quarters of a liter, to stay hydrated depending on the conditions.

That’s a lot of weight for water, which is why we suggest that you carry a 32 ounce sized bottle or smaller. If you do really want to use a large 64 ounce bottle then you should know, plus it’s also great for comparison to other bottle sizes, that a bottle of that size will last for about three or four hours of consistent drinking.

This makes a large vacuum bottle a great luxury item if you can prioritize your pack and spare the weight, but without further ado Paragon Trails presents our curated list of the very best BPA free double walled vacuum bottles and thermos flasks available that you can find on the market today.

5. Thermos Stainless Steel King 50oz Vacuum Insulated Bottle

The highly popular and well-manufactured Thermos King Stainless Steel series starts off our list at number five and is a top of the line double walled vacuum insulated bottle that has a great carrying handle for portability.

If you want to get extra creative with the handle you can loop paracord through it about a dozen times, and then loop it through a carabiner. That way you can hang your thermos off a strong and secure loop on your pack and store extra paracord for numerous purposes as well.

For colors, the Thermos King comes in five varieties: Army Green, Midnight Blue, Cranberry, Matte Black, and Stainless Steel. This is also the order of the most expensive color option to the least expensive, respectively.

One wonderful feature about this bottle is that for an entire day you can retain very hot temperatures inside, and yet have a cool to the touch bottle available for any hot soup or beverage you may ever need.

However, the manufacturer does suggest to never leave any food or beverages inside the container for longer than a day due to spoilage rates of foods.

They also strongly warn to never use carbonated beverages or dry ice inside the bottle since the stopper, lid, or contents of the container can be ejected, and this applies to other vacuum bottles as well.

Another safety measure is to never drink directly from a vacuum bottle unless it’s designed for it with a squirt nozzle.

In general, this is because the contents of a vacuum bottle can be near boiling point inside and really hurt your mouth. Always pour the contents into a cup, blow on the liquid a lot or carefully hold onto it, and even add ice if it’s available.

While the Thermos Stainless Steel King Series vacuum bottle comes in at number five on the list, it’s still an absolutely wonderful vacuum bottle with a great hot and cold temperature retention duration of a full day.

Plus, with a strong and sturdy handle, a stopper plug with a convenient pour hole, and a very large top lid cup for consuming delicious foods and beverages, there’s really not much more you can ask for in a bottle.

4. Hydro Flask Stainless Steel 40oz Vacuum Insulated Bottle

The Hydro Flask vacuum insulated and double walled thermos bottle comes in at number four on our list with a super convenient built in loop for affixing the bottle to your pack as well as a spout for easy access to liquids.

As we said before, it’s ill advised to drink searing hot liquids directly from a thermos bottle due to the potential for injury, but the spout on the Hydro Flask bottle’s still amazing for direct drinking cold refreshing beverages.

If you’re looking for a faster pour, or you in fact do want something hot, you can always twist the secure top lid and get your desired amount of liquid that way, however the flow rate really is quite good on the nozzle.

There are six color options available for the Hydro Flask and they are: Black, Frost, Graphite, Olive, Pacific, and White. Fortunately, all of the color variants available are the exact same price.

The Hydro Flask 40oz (~1.14L) also has a wide mouth top which makes cleaning using a soft scrub brush simple to use. If you do find yourself with access to ice, the bottle can easily accommodate that as well, but take care placing ice cubes into the container, or into any other container for that matter.

When an ice cube, or something hard falls onto stainless steel the result can be small dents similar to how hail reacts with cars, or frozen food does with a stainless steel cooking skillet. Simply place the ice cubes into the bottle, and then fill with filtered water to prevent any possible denting.

If you’re going to use a Hydro Flask what we would also suggest is purchasing a silicone sleeve to protect the exterior of the bottle. This isn’t something we suggest only for the Hydro Flask either, this is truly best practice for all vacuum bottles to protect them so they can last a very long time.

While the Hydro Flask does have a short hot temperature time, the bottle really shines for cold liquids and has a very convenient drinking spout for easy access to thirst quenching beverages.

If you plan to use it for hot beverages you’ll have to resupply for hot water every time you have a meal, but it’s really not that big of a deal since you’ll simply switch to a cold beverage once you’re finished with the first.

We struggled to place this bottle in the number four spot, but due to its below average hot beverage temperature retention we had to place it here. It’s still a great bottle though, extremely well-manufactured, very highly rated, and an absolutely wonderful lightweight addition to add to your kit at only 1.1 lbs or 0.50 kg.

In fact, if you’re long distance hiking and backpacking we suggest the Hydro Flask over the Stanley Classic, the next vacuum bottle on the list, due to the extreme light weight of the Hydro Flask.

The only reason the Hydro Flask 40oz is fourth on the list is because of its low hot temperature retention, but it’s still an amazing bottle that will absolutely not disappoint you.

3. Stanley Classic 67oz Vacuum Bottle

Upon reviewing the Stanley Classic Vacuum Bottle we were certain that it would have been overtaken and outstripped entirely now by some more advanced vacuum bottle technology, but the Stanley Classic’s truly incredible.

In fact, if it weren’t for the heavyweight status of this bottle, it would be in the number one slot. The only advancements that other bottles have over the Stanley Classic bottle are more lightweight materials for construction, but in almost every case, these other bottles sacrifice durability or temperature retention and fall short of the Classic.

The Stanley Classic really is in a league of its own too for durability since you can see these bottles still around fifty or more years later in great working condition and only very minor damage to their outer casing, if any at all.

The entire interior of the bottle’s made from a high grade 18/8 stainless steel, and for color options there’s a very wide variety: Hammertone Green! This is the same and only color option that’s been available since the year 1913 when the company was founded!

Stanley’s a family name and a trusted company with extraordinarily durable vacuum bottles, but for hiking they’re kind of tricky to use and honestly not great for very long hikes unless you have them secured well in your pack within your center of gravity. Although they’re exceptional in every way, really their only drawback is how heavy they are.

With a full bottle that’s 2 quarts in size, about 1.9 liters, you’re looking at around 6.62 lbs, or about 3 kg. That’s a lot of weight if you consider that a 200 lbs person only wants to carry about 40 lbs, or twenty percent of their bodyweight, at the absolute very most. In conclusion, this thermos can take up anywhere from 15 to 20 percent of your total desired carry weight.

If you’re going to use the Stanley Classic, we’d suggest using it on day hikes to your favorite destination, or on a single or a few night hiking and camping trip.

The reason for this is because while the bottle’s fantastic it’s really not great for transporting, but once it’s at its desired destination sitting next to you by the fire, it’s amazing.

We truly wrestled with placing the Stanley Classic this high up on the list, but due to its exceptional vacuum bottle technology and world class durability, it definitely deserves this slot on our list at number three.

2. GSI Outdoors Microlite 33oz Vacuum Bottle

With new technology being invented every day we get to enjoy the spoils in the form of new ultralight hiking gear. GSI Outdoors, founded in 1995, is a relative newcomer to the block compared to a company like Stanley, but they’re continuously redefining the industry with fantastically crafted, durable, and affordable hiking and backpacking gear.

The GSI Outdoors MicroLite is no exception to their fantastic line of products and has one of the lowest weight to volume ratios. What this means is that because of the construction of the bottle it can hold more liquid using fewer materials than other bottles, while still maintaining hot and cold temperatures exceptionally well.

In fact, the Microlite only weighs 13 ounces, or about 370 grams, and is easily one of the lightest, if not the absolute lightest one liter vacuum bottles available on the market today.

According to the GSI Outdoors website, the Microlite’s one third lighter than other bottles, and containers 25 percent more liquid than traditional vacuum bottles of the same size.

Testing that assessment by the company’s simple by using a calculation of dividing the weight of the vacuum bottle by its liquid capacity. Then, by comparing that value to the other vacuum bottles, what the data reveals is that the Microlite’s overall container weight per one ounce, or liter is fewer than all others.

The Microlite is an exceptionally well-engineered piece of hiking and backpacking equipment, and easily one of the absolute best thermos bottles you can buy.

The GSI MicroLite also has a bunch of color options and they include: Black, Fuschia (Seen Above), Blue (Light Blue), Mariner (Dark Blue), Aqua, Green, Olive (Brown), Brushed Stainless Steel, and White, and all the color options are the same price.

While the color options are really nice we would suggest the brushed stainless steel variant, as with all other vacuum bottles, because the exterior of any bottle when it is painted can chip or crack over time.

The GSI Outdoors MicroLite really is an awesome vacuum bottle and should be added to every hiker’s arsenal since it’s such a lightweight investment to add to your pack.

If the next option, the Klean Kanteen isn’t available due to limited stock, we absolutely suggest the GSI MicroLite, and if you’re an ultralight backpacker, this is the ultimate choice for a vacuum bottle.

1. Klean Kanteen Classic 64oz Vacuum Insulated Bottle

At the top of the list and one of the most sought after vacuum bottles is the Klean Kanteen Classic 64oz vacuum insulated bottle. This thermos flask is truly exceptional with among the highest iced temperature retention at 100 hours, and 30 hours for hot beverages.

The reason that this bottle is at the number one slot is because it’s a sort of synthesis between the GSI Outdoors MicroLite, in terms of light weight materials and advanced vacuum technology, combined with the hot and cold temperature retention and durability of the Stanley Classic bottle.

The Klean Kanteen 64oz bottle really represents the highest quality products available on the market today, the only drawback really is the smaller mouth size which requires a more little brush to clean the interior compared to other bottles.

With the top loop affixed to the cap the Klean Kanteen’s super easy to store on your pack too. We highly suggest using the paracord method which entails wrapping paracord through the loop a couple times and then through a carabiner to add some extra utility to your bottle.

If you want you can also grab a sleeve to wrap around the bottle to cushion and protect it from damage. A dedicated bag for your vacuum bottle is really nice and a great option we suggest is the GoNovate 64oz bottle pack with pockets and sling style or carrying handle for easy transportation and accessibility.

Sparing no expense the Klean Kanteen 64oz vacuum insulated bottle is one of the absolute greatest thermos flasks on the market today, but the only drawback is availability.

Since the vacuum bottle’s exceptional there’s a very high demand for the product which makes it difficult to purchase the 64 ounce version, especially in different colors.

Even though there’s around ten color options, most of the time the only variant available’s the brushed stainless steel which we actually suggest you pick up if it’s available since stainless steel can’t chip from any slight damage during hiking and backpacking excursions.

If this bottle isn’t available in the 64 ounce variety, we wouldn’t suggest settling and instead would recommend the GSI Outdoors MicroLite, but grab this if it’s available, or someone else will.


Each bottle has a specific use, but a couple of them reign supreme. In our first slotis the Klean Kanteen 64 ounce vacuum bottle which excels at keeping beverages hot and cold for very long periods of time while remaining very durable.

Due to the available of the bottle however, the GSI Outdoors MicroLite is an exceptional secondary option and is almost a no brainer due to its price, and super lightweight material construction.

If you find yourself on a short hike though, or you’re camping in the same spot for a few days and want some hot beverages then the Stanley Classic vacuum bottle will be the best option.

For all others you can’t go wrong with the Hydro Flask bottle with the spout nozzle, or the Thermos King series of vacuum bottles and they’ll be great as an all around bottle for any situation, and no matter which one you choose there’s no way you’ll be disappointed.


We absolutely love our Stanley Classic bottle for camping, and our GSI Outdoors MicroLite for backpacking and foraging trips into the forest. They’ve both been such great bottles, and once you pick up either of these bottles in the forest for the first time, you’ll realize what you’ve been missing out on as you sip on your hot tea, coffee, or hot chocolate.

We hope that we’ve helped you find the perfect vacuum bottle for your adventure and want to hear from you in the comments down below if you get the time to write to us.

Since we’ve only had the chance to hold and test the Klean Kanteen bottle, if you do get the chance to purchase this highly rated and outrageously exceptional bottle let us know.

Anyways though, thank you so much for being here, have a wonderful day, and as always, Happy Paragon Trails!


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