Product Reviews

The Best Vacuum Bottle Thermos Flasks for Hiking and Backpacking

Sipping a hot drink throughout the day from a thermos while walking across the countryside is a luxury. While thermoses can be heavy, they are worth the pack weight. Here are our top picks for the highest quality thermos flasks on the market.

When you’re out adventuring on the trail it’s really convenient to have pre-boiled water available to quickly make some hot tea, or coffee. This is where a thermos flask comes into play, but you need to ask yourself two questions first.

How much hot or cold water will you actually need on the trail and how much weight are you willing to carry? Whether you’re looking to carry just enough for a couple cups, or you’re more inclined to carry a lot more, we have selected some of the best thermos flasks for hiking on the market below.

What are some of the best thermos flasks for hiking?

  • Stanley Classic Vacuum Bottle
  • Thermos Stainless Steel King Vacuum Insulated Bottle
  • Hydro Flask Stainless Steel Double Wall Vacuum Insulated Water Bottle
  • GSI Outdoors 67462 Blue 1 L Vacuum Bottle

When it comes to thermos flasks we’re going to start by saying that we believe a vacuum insulated bottle should be at least double walled. This means that when it comes to preserving the temperature of the liquids inside the bottle, the duration of the heat retention will be MUCH longer. Standard vacuum insulated bottles tend to be only single walled, and will only keep liquids hot for twelve hours or less.

Often times a hike will start early in the morning, and can last a long time depending on your energy levels. The hot soup, coffee, or tea that you prepared before the hike began will be likely be cold by the time you’re ready for it if you’re using a single walled vacuum insulated bottle. This is why we have been so strict in our decision making when it comes to the products in this list because we want to provide you with the highest quality and best thermos flasks for hiking on the market.

Below is our highly curated list of bottles that are BPA free, double walled, vacuum insulated, stainless steel, and rated for preserving the temperatures of hot and cold liquids for at least twelve hours.

Stanley Classic Vacuum Bottle

No list would be complete without the most iconic vacuum insulated bottle on the market. The Stanley Classic Vacuum Bottle has been in circulation for many decades, and is a very heavy and almost indestructible bottle that can last you a lifetime.

The flask comes in five different sizes ranging from 16 ounces all the way up to two quarts (half gallon), and the entire product is BPA free including the plastic used in its construction. The top lid doubles as an 8oz cup, and the screw in lid can be removed halfway to double as a spout for more easy pouring.

After reviewing this product here at Paragon Trails we tend to feel like the largest bottles, (the 2.0qt and 1.4qt bottles), are too unwieldy, take up too much pack weight, and are awkward to handle, but all the other sizes can be a great addition to your gear set and even boast a lifetime warranty in the event of their exceptionally unlikely failure.

Thermos Stainless Steel King 24 Ounce Vacuum Insulated Bottle

Thermos Stainless Steel King 40 Ounce Vacuum Insulated Bottle

Thermos Stainless Steel King 68 Ounce Vacuum Insulated Bottle

Next on the list is the Thermos Stainless Steel King set of bottles. These vacuum flasks come in three varieties, the 24oz, 40oz, and 68oz sizes, and are particularly special when it comes to their maximum temperature retention.

The first bottle, the 24 ounce, has the shortest hot liquid temperature retention at just 12 hours, and 24 hours cold, but its counterparts, the 40 ounce and 68 ounce bottles, have an incredible 24 hour maximum temperature retention for both hot AND cold. This is unique for vacuum insulated bottles, and with this specification it definitely ranks as one of the best thermos flasks for hiking on the market.

However, there are two drawbacks to these two large vacuum bottles. First, in the same line of thought as the largest Stanley Vacuum Bottle, these are very heavy when filled with liquids and take up a lot of pack weight. This might be a con, or it may not, it’s all up to the individual, and how they allocated their pack for weight. Second, these bottles only have a 5 year warranty, unlike the Stanley bottle listed above, which hav a lifetime warranty. This really shouldn’t dissuade you too much though because these bottles are tough and can probably be used as a defensive weapon to fight off a bear.

These bottles, also do have a nice and strong handle on the side to make them more manageable. If you have the space in your pack, or you’re looking to gain some muscle, these really are some of the finest thermos flasks you can buy. We would suggest the 40 ounce bottle here at Paragon Trails because it’s the perfect balance between temperature retention duration, and size and weight.

Hydro Flask Stainless Steel Double Wall Vacuum Insulated Water Bottle

Coming up next is the exceptionally popular Hydro Flask. The vacuum insulated bottle is double walled, and contains food grade stainless steel on the interior to protect your liquids from the elements. These bottles will retain temperatures for cold drinks for up to 24 hours, and for hot liquids up to 12 hours, regardless of what’s going on outside the bottle.

The bottles come in four different sizes, 18oz, 32oz, 40oz, and 64oz, but as we stated previously, the two largest sizes will likely be too heavy to carry with you on the trail. The advantage of these bottles though is that there is a useful carrying handle on the top of the bottle allowing for it to be hooked to a backpack with a carabiner with ease. If you’re looking for a really solid bottle we would suggest going for either the 18oz, or the 32oz. bottles.

GSI Outdoors 67462 Blue 1 L Vacuum Bottle

In the top slot, and considered the best thermos flask for hiking by us here at Paragon Trails, is the Vacuum Bottle by GSI Outdoors. The reason we have selected this bottle as the best is because of its amazing ability to retain hot and cold temperatures. This incredible vacuum insulated flask can retain hot temperatures for up to 30 hours, and cold temperatures for up to 32 hours! It is difficult to find any other bottle on the market with those specifications, especially at this price point.

What we love the most about this bottle is that you can boil water in the morning, and there is absolutely no way that it will ever go cold on you. Even if you forget that you boiled the water, go to bed, and wake up the next morning, the water will still be piping hot inside. This bottle is also completely leak proof, so if you’re on the trail you’re not going to get splashed by searing hot water, even if you’re rough with it.

Another advantage of this flask is that it is lightweight. Since the maximum capacity of the bottle is one liter, or about a quarter gallon, you’re not carrying around a bunch of water for miles, and it will fit in almost all backpack water bottle holders, so you don’t have to worry at all about storing the bottle on a carabiner.

We really love this vacuum flask and encourage you to check it out for yourself. Even if you’re in between hikes, it’s great for work, and school.


With the way the market is today, there are countless different vacuum flask products that you can bring with you on the trail, but after careful consideration we do believe these are the best thermos flasks for hiking that money can buy. If you disagree with our list, or you can think of an even better thermos flask, we would love to hear back from you. Please do leave a comment below! Thanks so much, and have a wonderful day!

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