Flasks are more 'smell prone' than 'stain prone' – none of the flasks we tested had any staining after cleaning, but some retained a faint coffee smell. After Stanley, I found the Thermos – a brand which has become synonymous with insulated flasks – to come a close second in terms of heat retention. My hot water was 93.6°C at 8:25pm, and I already had my suspicions, because the exterior was markedly hot compared to the others – a sure sign of heat escaping. At 8:25am it was 34.8°C – a significant temperature drop of 58.8°C after 12 hours. Unlike the other flasks, my cold water and cubes didn’t get colder – it got hotter. The marketing blurb says it keeps contents hot for 28 hours, or cold for 90 hours, which based on these results I can’t really see happening.

Capacity: 1 litre (33oz) / Temperature test: 0 hrs 90°c, 90 mins 85.5°c, 4 hrs 79.1°c, 6 hrs 74.3°c, 8 hrs 69.9°c, 24 hrs 44.5°c / Made of food grade 18/8 stainless steel that doesn’t impart or retain flavour / Lid doubles as a mug ensuring you always have a cup handy / Silicon sleeve / Drinking stopper opens and closes with a slight turn / Additional standard stopper for optimum heat retention included / Tapered design for easier handling / Large mouth opening is easy to fill and clean. BUY NOW: PRIMUSEQUIPMENT.COM When single-use plastics started getting a bad rap, S’well became the drinks bottle of choice for a host of celebrities and ‘influencers’. But they’re not all style over substance – the design consists of a triple-walled construction incorporating a copper layer for improved insulation. This flask is lightweight and practical – the ergonomic shape makes it easy to hold, the really wide mouth makes for easy drinking, filling and cleaning, and the grooved lid makes it easy to open, even if screwed on tightly. It’s sure to draw admiring glances if you leave it on your desk at the office. It’s just a shame that the capacity is a bit small, and it’s relatively expensive for a little flask. Full Specifications If you want to carry your flask long distances, it’s a lightweight option – weighing 400g (14 ounces) with canteen cap, or 380g (13.4 ounces) with sports cap, while empty.

Primus Trailbreak EX 1 Litre

To help you choose which one to invest in, I tried and tested a selection of flasks that promise to keep your beverages colder and hotter for longer, measuring how much heat was retained or how cool they kept respectively over a period of 12 hours. This flask has a familiar design with a classic ‘pop’ stopper that makes for easy pouring. With cheap, inferior flasks these are often prone to leaking but with this Outwell version the component seems well-made and reliable. It certainly didn’t leak on test. It’s a simple, inexpensive flask that makes use of a classic tried and tested design. The wide mouth makes the flask easy to fill and clean, while the cup’s plastic liner ensures you won’t burn your mouth. On the other hand, it is fairly bulky for a 750ml flask, with a small cup compared to some other designs. The external finish is also a bit slippery and prone to scratching. Full Specifications BECAUSE WE CARE ABOUT THE ENVIRONMENT - By using our sustainable vacuum flask, you are actively contributing to reducing the waste production of disposable coffee cups & saving your hard-earned money.

Or even What are the Top 10 affordable (best budget, best cheap, or even best expensive!!!) 2 Cup Thermos Flask available? Etc. Founded in 1997, we’re the UK's largest dedicated outdoor clothing and equipment retailer and have been offering our customers unbeatable VALUE for money and outstanding quality for 25 years.

Sigg Hot & Cold 1.0L Flask

Like almost any decent bit of outdoor kit, a good vacuum flask should also be robust and durable. All the flasks we tested are made of high-quality 18/8 food-grade stainless steel that resists dents, dings and scratches. The trade-off with steel flasks is that they can be heavy, although modern designs are shaving weight all the time, and in some cases, they now weigh little more than a standard plastic drinks bottle.

Button-operated lids are more efficient to use than twist-and-pour stoppers – we found the button-operated lids to be more secure than the twist-and-pour stoppers. My hot water was 91.3°C at 8:36pm; at 8:36am it was 75.7°C – a temperature drop of 15.6°C after 12 hours (not that much more than the Stanley, and still piping hot enough for a decent brew). My cold water was 4.4°C at 11:13am, and as with the Stanley, 12 hours later it was even colder – at 1.7 °C. You probably wouldn't describe the scientific rigour as laboratory standard – but the tests did replicate the kind of environment you'd actually use these flasks in, either filling up your tea or coffee at the start of the day, or icing water. And the results were certainly interesting. While the cold water tended to record similar temperatures across products (with the exception of Klean Kanteen, which I'll get to), there was a significant degree of difference when it came to heat retention. My conclusion is that if you really care about keeping your caffeine hot, you should choose your insulated flask wisely. It comes with two cups with proper handles, so it's a great tea flask. It works well for families and small groups, making 5 or so generous servings. The twist stopper has a cunning hidden compartment in which to store milk or sugar; which I liked.Unlike many flasks, it is also dishwasher safe – a big bonus in my book. The lid doubles up as a decent-sized cup and provides extra insulation; a handle on the side makes it easy to lug around and grip while battling the elements, but there’s no chance of leakage. While primarily made up of stainless steel, some parts are plastic – but it is BPA-free (an industrial chemical used in water bottles and similar that many people prefer to avoid). LEAK PROOF DESIGN: Thanks to a tight fitting, easy pour screw top these insulated flasks have been designed to provide a leak free experience for you when hiking, camping, going to the gym, work, on the train commute or simply around home. So, whether you're planning on travelling the world or exploring closer to home, we have what you need for your next ADVENTURE. Since the American manufacturer, Thermos, came to fame, the term has become slang for vacuum-insulated flasks. Although the terms are largely interchangeable, the original scientific phrasing is 'vacuum flask'.