Best flasks and travel mugs that will keep drinks hot (or cold) for hours

This 700ml flask boasts all the perks of a larger option while stripping away the extra bulk. With a copper coating to improve heat preservation, it boasts the ability to keep drinks hot for up to eight hours. Impressively, we found ours was still nice and warm after around 20 hours, which is pretty good going. Equally impressive was the flask’s ability to keep drinks chilled – there were still ice cubes in our cold water after 24 hours.

Should you prefer sipping hot tea and coffee from a cup rather than straight from the flask, this is a brilliant, compact choice. Unscrew the flask’s lid and it becomes a cup, although, admittedly, quite a small one, so you will probably need to fill it a few times to quench your thirst.

The flask isn’t dishwasher safe but this is a minor annoyance with an otherwise very efficient and purse-friendly piece of kit.

As Thermos has become synonymous with insulated flasks, naturally, the supersize “steel king” was going to be pretty hard to beat. It has a whopping 1.2l capacity, and we were genuinely quite stunned by how hot it kept our water over 24 hours. Most of the ice in our cold drink was still solid after 24 hours, too – you could fill your Thermos in the morning and it will still be refreshingly cool the following day.

It’s sturdy but surprisingly lightweight for its size, and the handle, which is collapsible (to save on space), helps with one-handed carrying and pouring. Everything about the steel king feels exceptionally well-made – from the thick-rimmed stainless steel cup (which doesn’t have a handle but is still nicely capacious) to the twist and pour stopper. Our one quibble would be the stainless steel cup can feel hot in your hands when the liquid inside is especially scorching. However, never having to completely remove the screw cap before pouring will make for smoother al fresco pit stops. A classic for a reason, we can’t knock it.

A conscientious choice when it comes to the materials used and environmental impact, this insulated flask from Ocean Bottle is largely made up of recycled stainless steel and ocean-bound plastic. On top of this, the brand says buying one bottle will fund efforts to prevent the equivalent of 1,000 plastic bottles from ending up in the ocean as plastic waste – so you can feel genuinely good about buying this one.

Water, coffee and even thicker smoothies and soups aren’t off limits, thanks to the bottle-esque mouthpiece – although, we did find the mouthpiece can momentarily drip slightly once the lid has been removed.

Easy to grab, owing to the flexible carry loop, you can unscrew the larger lid for cleaning and chucking in ice. Our drinks were still impressively hot after six hours and refreshingly chilled after the same amount of time – cold enough that some of the ice we dropped in there was still intact.

This flask is robust enough for outdoorsy excursions, but not so bulky that you wouldn’t reach for it for everyday use, so it’s a good choice for taking to work, too. While Yeti doesn’t specify a maximum heat retention time, we found that our water was still hot after 24 hours, while some of the ice in our cold water managed to survive for just as long.

Everything from the matte surface to the range of fun colours on offer suggests high-quality materials. We are also big fans of the aptly named hotshot cap, which, once swivelled to one side, will let you sip from any angle. However, something to remind us whether or not the swivel mechanism had been ‘closed’ would have been really helpful.

What we consider to be the perfect amount of liquid flows through at the perfect speed (although this will be quite subjective) and the hotshot cap didn’t let us down when it came to being completely leak-free.

Sleek and, thanks to being made with stainless steel, plastic-free, this flask from Klean Kanteen is an efficient and eco-conscientious choice. While not quite as capacious (750ml) as the flasks from Thermos (£30, Amazon.co.uk) and Zwilling (£34.95, Zwilling.com) despite its fairly bulky design, it’s still going to be an excellent choice for bringing on longer outdoor adventures.

It performed ludicrously well when it came to preserving drink temperatures – our hot water was piping hot after 28 hours. We were dubious about claims that it could keep iced water iced for 90 hours, and were flabbergasted to find it does exactly that (yes, really, almost four days).

Leakproof and cleverly designed, the flask features a twist and pour cap which can be poured from any angle – while slightly splashy if you don’t open it enough (or indeed too much) this is a really nifty way to save time and prevent some of the heat from escaping. We loved how capacious the stainless steel lid was too (216ml) and appreciated the wide mouth for comfortable sipping. Perfect when you’re gasping for a big cup of tea.

There’s something satisfyingly simple about this travel mug from Contigo. Press the large button on the lid, and your beverage will flow from a hole in the lid. As the flow of liquid is more concentrated than it is from larger mouthpieces, it feels almost similar to a mini vortex, which is fun. Our water was hot after five hours, and cold after 12.

Drinking from this flask is a one-handed operation, as you don’t need to unscrew the lid before taking a sip. The lock on the lid will also prevent the button from being pressed when you don’t want it to be – say, when it’s being pushed up against your laptop in your bag. The flask is also very compact, narrow (making it easy to hold in one hand) and lightweight to carry. It’s a sleek bit of kit when it comes to design as well, with its all-over metallic finish, although there’s a range of other colours to choose from, too.

If you feel uneasy about water quality while travelling, Larq’s self-cleaning water bottle is a high-tech investment that has blazed a trail with its patented UV-C light hidden in the lid, eliminating nearly all (99.9 per cent) of bio-contaminants inside.

Looking a little sci-fi, the flask has a button on the lid, which can be pressed for either a short (one minute) UV-C cycle or you can choose adventure mode (three minutes) for extra peace of mind. Beneath the intimidating tech, though, the purevis is also just an excellent flask – our water remained hot after 12 hours, and there were still cubes of ice in our cold water after 24 hours. Importantly, please note purification will be less effective with ice in the bottle, as this may partially block the UV-C light.

A clean bottle should help to keep that musty bottle smell at bay, and, while we admit we may have been swayed by the knoweldge our water was completely clean, we did find our water tasted fresher for being purified. We liked that the bottle will clean itself automatically every two hours and, unlike the rest of our tech, only needs to be charged every month or so. It is worth noting the brand doesn’t recommend using the bottle for drinks such as coffee and tea.

Chilly’s has become somewhat synonymous with stylish drinkware – from dreamy ombre to abstract and floral bottles, there are plenty of styles to choose from. While you can use the brand’s insulated bottles for holding hot drinks (ours did a good job of keeping water piping hot for 24 hours) we would say we preferred using ours for keeping drinks cold. Some of the ice in our cold water was still intact after 24 hours and, naturally, the water was refreshingly chilled.

The series two bottles boast an antimicrobial drinking collar, which is dreamy to drink from and can be removed easily when it comes to cleaning the bottle, or dropping in ice cubes. This can sometimes open with the lid when it hasn’t been screwed on tightly enough, though, but the lid itself is completely leak-proof. Plus, the handle on the lid wins major points in terms of portability, while the protective rubber base means you don’t need to worry about making an obnoxious clang when setting down the flask.

This is a really solid little Thermos that does pretty much everything you’d ask of a flask. Thermos claims the flask retains temperatures for 24 hours, and it certainly did keep water cold and coffee warm over the full period. We were particularly impressed by how secure the flask felt, and we had no concerns about it leaking while bouncing around in our work bag on the Tube, in the car, or even while cycling, so it’s ideal for commuting.

The silicone rings make the flask feel extra sturdy, which we appreciated when out hiking, but, for most outdoor adventures, we’d probably opt for a flask that has a greater volume. That being said, it’s lightweight and has a decent 500ml capacity, which feels just right for taking tea or coffee into the office.

As photogenic as they come, this insulated flask from Partner In Wine has been purpose-built for keeping your bottle of plonk cool for up to 24 hours. A great purchase if you really resent sipping on ever-so-slightly warm wine during the summer months, this would be perfect for filling up before picnics, festivals and any al-fresco gatherings when you would rather leave the wine cooler at home. It will fit one bottle of wine perfectly, and feels markedly lightweight for a bottle of this size (750ml).

While we weren’t able to test this flask during the summer months, we still found that fridge-chilled wine stayed suitably cold for 24 hours. There’s no chance of vino spillages, either, as we can attest that the lid, which screws on easily and securely, is leak-proof. If you like ice in your wine, it’s worth noting the mouth of the bottle is quite narrow (indeed, wine-bottle narrow), so typical ice cubes won’t fit through.

While the black colour we tested is currently sold out, there are plenty of other dreamy hues to choose from, including soft pastels and all-over stainless steel.