The best hiking flasks: for keeping beverages and food hot in the wild

Armed with the best hiking flask, you can enjoy a hot brew pretty much anywhere. Coffee, tea, soup, saucy pasta – they all just taste better in the great outdoors, especially if you're perched watching the sun rise over a distant ridge line, sat listening to the sounds of the forest or looking out across the sea with breaking waves tickling your feet.

With the winter hiking season upon us, the best hiking flask is more than just a luxury, it's almost a necessity. As anyone who ventures above the snow line will know, having a hot drink to hand is a great way to keep warm. Winter campers also enjoy the benefits of having an already steaming hot drink ready when they reach camp.

The best hiking flasks are designed specifically to maintain the temperature of their contents for several hours. Many feature a handy mug as a lid and most come in a range of sizes. Flasks with a smaller capacity are ideal for your hiking backpack on fast and light missions, while larger options are great for car camping and the like.

So, whether you're off with your best camping tent for a winter wild camp, or wanting a steaming pick-me-up for after an invigorating wild swim, our guide to the best hiking flasks has you covered.

Large hiking flasks

The Thermos Revival is a hiking flask that has some serious heritage appeal. With a history stretching back well over 100 years. The technology used in the Thermos (named after the Greek word for heat, therme) still owes a great deal to the invention the vacuum flask by Scottish scientist Sir James Dewar in 1892, which he created when he was supposed to be working on cryogenics. 

These classic-looking, tartan-emblazoned '60s-chic flasks are direct replicas of the brand’s much-loved original Model 18 design, seen everywhere from family photos to Famous Five books for as long as anyone alive today can remember.

This flask may look dated, by design, but it still works like a dream, keeping fluids hot for up to 18 hours and chilled for over 24 hours, while maintaining a neutral outside temperature so do don’t get any build up of condensation in your pack. The cup is quite small, but at least it screws securely to the top of the flask so it doesn’t become separated, and the system for opening and closing the main container is simple and functional. All in all, it's classy, reliable and very functional – a beauty of a flask that should last for many years.

Read our full Thermos Revival Flask review

There’s a family of four sizes in the Lifeventure TiV range, so finding the volume of vacuum flask that suits your needs should be easy, from a small, solo flask to a mighty family-sized affair. Each TiV flask is copper-coated to boost heat retention, and should be good for keeping hot drinks hot for up to eight hours, while keeping cold drinks chilled for as long as 24 hours (tip: add ice cubes to extend the cooling effect).

The deep screw stopper provides a reassuringly leak-proof closure, but you’ll need to unscrew it completely to pour a drink. Out on the trail, the stainless steel lid doubles as a handy cup and is a useful size on all four flasks in the range, while the slim body makes it easy to pour single-handedly.

The walker nominated to carry this giant flask in his or her rucksack has truly drawn the short straw… until the first drinks break… and the second… and the third! The great advantage of this double-wall vacuum insulation and the generous volume is that drinks stay unbelievably hot. Stanley claims a ‘stay hot’ time of 40 hours, and if you pack it with ice it will spend up to six days frozen!

On the other hand, it is a beast to carry, especially in a smaller day pack, and while the collapsible handle is useful for pouring when the flask is full, especially if you don’t have baseball mitts for hands, it can snag on clothes when you pull the flask out of a rucksack.

The fact that you’re as likely to see the Stanley Classic Vacuum Bottle on a building site as you are on a hilltop tells you everything you need to know about the flask’s bombproof build quality, which is reassuringly backed up by a lifetime warranty.

You’ll need a long brush to reach the bottom of the flask for cleaning, although it is dishwasher-proof – if your dishwasher is big enough to accommodate it!

Read our full Stanley Classic Vacuum Bottle review

Designed by camping and hiking specialist Vango, the stainless steel Magma Flask delivers everything a walker could want from a flask. Like Henry Ford’s proverbial Model T, you can choose any colour so long as it’s black, but that simplicity aside, the copper-coated double wall vacuum flask delivers impressive insulation to retain heat and keep cold drinks cool.

There’s no fancy lid – just unscrew the top and pour your cuppa into the lined cup.

The Vango Magma Flask is available in three sizes – 500ml, 750ml and 1-litre – so there’s a good range of choice from solo flask to family drinks, and all for bargain prices.

Read our full Vango Magma Flask review

Small hiking flasks

The bright colours of the Primus Vacuum Bottle range are, er, not just a pretty face on a functional item of outdoor kit. The powder coating gives enough purchase that it’s possible to unscrew the lid without taking off your gloves, which is a massive bonus when the mercury tumbles. Then it’s simply a question of pushing down the button in the centre of the stopper and pouring your drink. It’s not the neatest spout, and is far from ideal if you fancy swigging cold drinks directly from the flask, but on the plus side it traps heat inside to keep drinks warmer for longer. This ‘sealed’ stopper also makes it a little harder to assess how much drink is left in the Primus Vacuum Bottle – walkers will have to count the cupfuls they pour to keep track.

The lid serves as a handy cup, although as with most flasks in this review, the volume is pretty small, especially if you’re accustomed to the giant beakers of high street coffee outlets.

After use, the narrow opening makes cleaning a little difficult, particularly if you take milk in your coffee or fill the flask with soup, although long brushes are available. The click-close button also disassembles for cleaning, but it’s far from obvious how to do this.

Read our full Primus Vacuum Bottle 350ml review

If there’s one thing more likely to turn your walking buddies green with envy than having a flask of hot drink available throughout the day, it’s tucking into a hot meal while they chomp on soggy sandwiches. Pasta with pesto and cheese, chunky soups and hearty stews… whatever your midday masterpiece, this robust Thermos Stainless King Food Flask will keep it hot until it’s time for lunch.

The flask itself is short and fat, its 9.4cm diameter too wide to slide into a side pocket of a rucksack, but at only 14.2cm tall it squeezes inside a pack with no trouble. The lid conceals a handy, full-size folding spoon and you could use the insulated lid as a bowl if you’re sharing your meal, although most walkers should be able to manage the full contents on their own.

Thermos claims that once sealed, the Stainless King Food Flask will keep hot food hot for nine hours and cold food chilled for 14 hours. For optimum performance it pays to pre-heat the flask with boiling water prior to filling it with food, and once the wide lid is removed it doesn’t take long for an icy wind to cool food down.

The wide mouth does, however, make this pot easy to clean – only larger hands won’t fit inside it, and the five-year guarantee is a welcome case of a manufacturer putting its money where its mouth is.

Read our full Thermos Stainless King Food Flask review

The slim, stylish GSI Outdoors Microlite 350 Flip applies the spout technology of a water bottle to the science of keeping drinks kettle hot or ice cube cold. The flip-top lid and pouring spout lets you swig straight from the flask, which is ideal unless your drink is too hot to swallow (and watch out for your fillings if you’ve packed the bottle with ice). You can, of course, simply take a mug along with you (there’s no lid cup on the top, unlike the other flasks in this test), and if you want a flask to double up for your commutes it’s easy to have a mug ready on your desk at work.

The ultra-thin, 2mm walls of the flask lend it the slenderness of a supermodel while swallowing a surprisingly large volume of fluid given its dimensions – GSI reckons it can carry 25 percent more liquid than traditional vacuum bottles of the same size.

The push-button, flip-top cap allows one-handed access, which is convenient if you’ve got a map, GPS, camera or walking pole in your other hand.

As for the insulation, the Microlite 350 Flip will keep hot drinks hot for eight hours and keep cold drinks chilled for as long as 16 hours.

Read our full GSI Outdoors Microlite 350 Flip review

While insulated travel mugs offer a far greener alternative to disposable coffee shop beakers, suspicions about the security of their seals have left walkers reticent about trusting them beyond campsite use. As scores of positive reviews attest, however, Camelbak has solved the problem thanks to its Hot Cap, which converts insulated mugs and bottles into flasks. Cleverly, the Hot Cap is also compatible with Camelbak’s Chute Mag and Eddy+ water bottles, turning them into cold drink flasks.

The lid’s rotating twist valve opens and closes the flow of liquid, with the added convenience of 360-degree drinking from any side of the mug (handy for keeping your eyes on the road if you’re taking a swig while driving).

Out on the trail, the no-slip textured flask fits nicely in the hand, keeps hot drinks hot for six hours (a much better performance than most travel mugs), and then is straightforward to disassemble for a thorough clean.

Hiking flask comparison table

Choosing the best hiking flask

Volume

This is an entirely personal decision – are you carrying a hot drink only for yourself, for you and a partner, or for the whole family? For coffee lovers weaned on the giant beakers of Starbucks and Costa, the 350ml, one-person models may not be turn out to be the best hiking flask for a long day in the hills. Of course, the more liquid you carry, the more weight you carry in your daypack.

Dimensions

Where will you carry your flask? Tucked deep in your rucksack or in a side pocket for swift, easy access. The diameter of some of the best hiking flasks in this test is too wide to slide into many daypack side pockets. It’s also worth bearing in mind that a flask which fits snugly in your hand is easier to pour and avoids having to take off your best hiking gloves when the temperature drops.

Top/stopper

The traditional, deep, screw-in stoppers should provide the most secure seal (although most modern flasks are reliable), but they need two hands to unscrew and pour, and they let heat escape each time they are undone. Click tops that let you pour a drink without unscrewing the top retain heat better, but they don’t let soup flow very easily and they can be awkward to dismantle and clean. Drinking spouts that allow you to drink straight from the flask seem convenient, but if the flask’s insulation is any good the drink will be too hot to swallow for a long time.

Opening

If you want to use your flask for hot camping meals you’ll need a wider mouth and shallower depth to reach the bottom with a fork or spoon. The wider mouth makes cleaning easier because most people will be able to squeeze a hand and scourer inside.

Insulation

The primary reason for taking the best hiking flasks on a walk is to keep hot drinks hot or chilled drinks cold, so their insulation performance really matters. Pre-heating or pre-cooling flasks can make a significant difference to the heat/cold retention. Remember, too, that the more liquid in a flask the better it will retain its temperature, so larger volume flasks will outperform smaller rivals.

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