Best flasks: we recommend our favourite insulated drinks receptacles

With the benefit of keeping hot drinks hot and cold drinks cold, an insulated flask will earn its place in your rucksack all year round.

LFTO Gear Tester using an insulated flask

by Chris Williams |

There are few luxuries that dedicated hikers afford themselves, but an insulated flask is one of them. They go nicely with a hand-operated espresso maker (check out our article on camping gadgets to see what we mean).

We've curated our top-rated insulated drinks flasks to help you choose the right one for your next trek.

What to look for in an insulated drinks flask

Volume: Do you need something to keep a takeaway latte warm, or do you want a day’s worth of cuppas in your pack? Is it just for you, or will you be sharing the contents? These factors, along with how much weight you’re prepared to carry, will decide the volume of liquid you need to fit in your flask.

Weight: Remember, one litre of water weighs one kilogram. A flask will only get heavier when full, so consider the empty weight of the flask and its volume to avoid overburdening yourself.

Drinking method: Some flasks come with a separate cup, while others are intended to be drunk from directly. The latter of these may have different openings, and some will be better suited to cold drinks than hot, lest you risk burning your lips.

Robustness: Most modern flasks are less breakable than the traditional glass insulated models, but some are better than others. If you tend to chuck your pack around with gay abandon, it’s worth making sure you choose a tough one.

Level of insulation: Good insulation comes at a price, both in terms of actual cost and weight. Cheaper, lighter flasks may keep the contents warm for a few hours. But if you want your last sip of the day to be as hot as the first, you may have to spend a little more and tolerate the extra grams.

The best insulated drinks flasks

Stanley Classic Neverleak Travel Mug 0.47L

Best for day walks
Stanley Classic Neverleak Travel Mug 0.47L
Amazon

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Weight 329g | Size 209x72mm | Insulation 7 hours hot, 10 hours cold | Other volumes 250ml, 350ml

If all you need is something in which to carry a single serving of hot drink – be that a mug of tea, a takeaway Americano, or a brandy-spiked hot chocolate – the Neverleak is perfect. Best of all, it can be tossed in your pack without fear of leakage thanks to the 3-position lid.

GSI Microlite 1000 Twist

Best lightweight insulated flask
GSI Microlite 1000 Twist

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Weight 379g | Size 217x91mm | Insulation 18 hours hot, 32 hours cold | Other volumes 700ml, 500ml

The simplicity of the Microlite flask is what makes it so good. No fancy lids or pouring mechanisms on this remarkably lightweight insulated flask, just a single, reliable stopper that fills the wide-mouth opening. It efficiently holds onto heat and prevents any leaks.

Aladdin CityPark Thermavac Twin Cup Bottle 1.1L

Tea for two
Aladdin CityPark Thermavac Twin Cup Bottle 1.1L
Amazon

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Weight 595g | Size 293x93mm | Insulation 25 hours hot, 25 hours cold | Other volumes N/A

When tea for two is on the cards, this is the perfect solution. Cleverly storing two cups in its lid and with a leakproof easy-pour stopper, the Thermavac will keep its contents hot or cold for over a day and makes sharing an on-the-hill cuppa simple.

Thermos The Revival Flask 500ml

Retro and effective
Thermos The Revival Flask 500ml

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Weight 295g | Size 237x69mm | Insulation 18 hours hot, 24 hours cold | Other volumes N/A

Brimming with nostalgia – a Thermos just like your granny used to have – the retro Revival (also available in green and blue tartan) is also a highly practical flask for one. It features a removable mug, a flip-up pourer in its internal stopper, and excellent insulation figures.

360° Wide Mouth Insulated Bottle

Great value
360u00b0 Wide Mouth Insulated Bottle

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Weight 330g | Size 210x82mm | Insulation 24 hours hot, 12 hours cold | Other volumes 550ml, 750ml, 1000ml

This vacuum insulated bottle will keep drinks cool for 24 hours. Combined with its convenient sip cap (although it also has a wide mouth opening for filling and cleaning), it's ideal for cold drinks on the hill.

Mizu V8

Recommended
Mizu V8
Amazon

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Weight 434g | Size 255x89mm | Insulation 24 hours hot, 12 hours cold | Other volumes N/A

The V8 is simple, robust, and fairly capacious. We like there are loads of colours (this green being our favourite) and that it'll genuinely keep beverages hot for about 12 hours (cold beverages cold for 24 hours). However, it's mouth isn't as wide as the 360° flask, but it's still fairly easy to clean.

Hydro Flask Wine Bottle

Best for summit celebration
Hydro Flask Wine Bottle

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Weight 458g | Size 292x79mm | Insulation N/A | Other volumes N/A

This flask will keep your sauvignon blanc chilled or your mulled merlot hot for hours. It's designed specifically to swallow the contents of a whole wine bottle, but it works equally well for non-alcoholic tipples. We do of course say that if you're taking alcohol on your trek, be sensible and drink responsibly.

Stanley Master Unbreakable Thermal Bottle

Best for toughness
Stanley Master Unbreakable Thermal Bottle
Amazon

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Weight 1310g | Size 357x102mm | Insulation 40 hours hot, 6 days cold | Other volumes N/A

A proper traditional beefy flask that, unlike traditional flasks, is almost unbreakable. Big and heavy it may be, but if you need to keep tea on hand for the troops (or your walking buddies) this 1.3-litre bottle will keep its contents hot for up to 40 hours (or cold for six days).

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