Heat and cold retention is exemplary, with the Thermos lasting well over 24 hours for both. We found that it is particularly effective for cold drinks, with ice cubes still being solid after a 30 hour test we performed. Thermos have obviously squeezed out all routes for heat to get into the inner chamber of the flask. In terms of heat retention, it is excellent. Starting with hot water at 95 ℃, you can expect it to drop to around 60 ℃ after 12 hours, 51 ℃ after 24 hours and 40 ℃ after 36 hours. Pretty incredible. Capacity: 500ml / Temperature test: 0 hrs 90°c, 90 mins 89.3°c, 4 hrs 82.8°c, 6 hrs 79.2°c, 8 hrs 75.3°c, 24 hrs 50.9°c / Stainless steel interior and exterior / Cool-touch, no-slip finish / Protective silicone rings for ultimate durability / Two part stopper for smooth pouring. BUY NOW: THERMOS.CO.UK The downside of this approach is that a high capacity flask will be big and bulky. There’s no getting away from it. However, if you’re able to split your gear equally between all members of the team (e.g. one walker carries lunch, another carries the picnic blanket etc) then overall you will use less space than if you each carried smaller flasks.

As we said before, vacuum insulation is important for keeping the heat energy inside your flask, and the Hydro Flask does this well. It is made of stainless steel that is extremely good for heat retention. The GSI employs a thin but reliable stainless steel wall that reduces the weight and also increases the internal space of the bottle. According to GSI, you can store 25% more liquid than any other flask for the same size. Key attributes: Leakproof, practical design enables one-handed drinking, wide mouth for easy filling and cleaning You can leave your house with a full bottle of coffee on Friday evening and can have a nice walk with a cup of hot coffee on your weekend destination even on Saturday evening! You will definitely get a duration of 24 hours, and this model performs equally well for hot and cold temperature contents. In Use Some thermos flasks are designed to be handily-sized for solo use on hikes and outdoor adventures. Others are larger for bigger groups or car and campervan travel. Choose wisely, or get a couple for different activities.

Primus Trailbreak EX 1 Litre

If you’re after a large flask, the Oneisall 2L is a great stainless steel option with a lovely ergonomic design. This is a high-quality two litre flask which is capable of serving drinks for the whole family – great to bring along for day trips in the car or campervan. The temperature performance is excellent and compares favourably to the other top performers in the world of elite flasks. Your coffee will remain hot after 12 hours and your ice cubes will remain unmelted after a very decent 24 hours. So, you can still pour a chilled drink even after a long walk on a hot day. Part of this ability is due to the clever ‘honeycomb’ insulation used inside the Hydro Flask. It worked well for us! Thermos should just rename their 1 litre ‘Light and Compact’ vacuum flask as “The Daddy” because it effortlessly delivers everything you would expect from the company who developed the vacuum flask as we know it today from Sir James Dewar’s original prototype in 1904. You should carefully consider the required capacity of your flask before buying one. Have a think about how many people will require a drink from it, and who will be the person carrying it around. Is it for home use (some people take a flask to their home office in the garden), or carrying on a walk for rest and recuperation? The Oneisall measures 34.5 x 11.5 x 11.5 cm and weighs 1.2kg. For a large capacity flask, those are not actually bad specifications. And it really does look the business! Beautiful lines as they say!

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 Available in a range of colours (we like the electric blue), the flask is highly suitable for camping trips and general travelling refreshments. Pouring is very easy due to the superb flexible handle fabricated from silicone. The Stanley 18-8 flask is the best option for a solo user in our opinion. It is a great performer which looks superbly rugged for your next arctic exploration and goes about its job efficiently, discreetly and expertly.

The original and, judging from the results of our temperature test, still the best. This stainless steel flask is very durable, with a silicone base to protect against dents. The two-part stopper closes securely yet pours easily and has an integrated cup. In terms of outright heat-holding performance for up to 8 hours, nothing can touch the Ultimate Series. It was the best-performing flask we tested overall. It is relatively lightweight too. And if you’re concerned that the 500ml capacity will be too small, it’s worth noting that Thermos also makes a larger 900ml version. Full Specifications For a group hike, you need to keep lots of liquid on board for everybody to get a cup. If this is your plan then you should buy a thermos which can hold lots of liquid for the whole squad. It is definitely more space efficient to use one big flask for the group rather than several small, individual flasks. If you think about it, the majority of a flask is wasted space and not actually used for carrying liquid – it is there for the heat insulation. Better to just carry one big flask.

A range of scientific research has shown that BPA can seep into food or beverages and potentially cause a range of issues for the brains of fetuses, infants and children. Additional research suggests a possible link between BPA and increased blood pressure.

S’well Roamer 64oz Flask

The Okadi is a 2.5L flask which offers extremely good capacity for both family and group adventures. It is fabricated from stainless steel which gives excellent core strength and durability. This thermos will last for a long period of time indeed. You can see that a thermos flask will be a great companion for any outdoor activity! Using a Thermos Flask is Environmentally Friendly Thermos flasks use an ingenious mechanism which consists of dual layers separated by a vacuum cavity between them. The vacuum is a region of space with no air or anything at all in it – this creates a natural barrier to heat leaving or entering the innermost chamber holding your drink. That’s why liquids in the flask remain hot or cold for longer than they would in a standard plastic bottle. Capacity: 600ml (20.3oz) / Temperature test: 0 hrs 90°c, 90 mins 79.6°c, 4 hrs 66.5°c, 6 hrs 58.3°c, 8 hrs 51.6°c, 24 hrs 22.2°c / Stainless steel construction / Wide mouth opening /