Top 6 Best Thermoses of 2022


We have tested the best thermoses on the market in 2022 and name the Thermos King Flask as our Best Choice. This classic model from the company that invented thermoses has very good heat retention, seals tightly and can easily withstand a knock or two. We were also impressed by the Stanley Adventure Vacuum Bottle, a reliable and classic thermos made from stainless steel with a clean design and good build quality. Alternatively the IsoSteel Quickstop is a cheaper thermos with good heat retention capacity for those on a budget.

Top 8 Best Thermoses of 2022

How we carried out the test

Our tests are independently conducted and reflect the test editor's honest and objective opinions. Selection of products and test results are in no way influenced by manufacturers, retailers or other internal or external parties.

We carried out the test ourselves and tested all the products as they are intended to be used in reality. We first took the thermoses out into the wilderness, where they were used by two outdoor-loving families. The families were asked to open, pour, drink from, drop and handle the thermoses in all possible ways, with and without gloves and with both small and large hands. We then carried out more controlled testing both indoors and outdoors. In these tests we filled each thermos with boiling water and measured the temperature after 30 minutes and then after 1, 2 and 4 hours respectively. We also stood them upside down to see if they leaked at all.

In our assessment we focused on the following areas:

  • Heat retention capacity: How effectively does the thermos keep its contents hot?

  • Construction: How impact and shock resistant is the thermos? How well does it prevent leakage? Is it well designed? How heavy is it and how big is the opening you drink from?

  • Ease of use: How light, neat and stable is the thermos? Can you remove and replace the lid even with damp gloves or weak hands? If the thermos has a snap lid can it be resealed easily? Does it fit into a smaller rucksack? How easy is it to clean? Is it dishwasher safe? How clear are the instructions?

We gave each thermos a score according to its value for money; effectively judging how good each thermos performed in relation to its price tag. We thus had higher expectations for an expensive thermos than for a cheaper one, and vice versa. We counted thermoses costing less than £25 as budget class, and those costing between £25 and £40 as medium class. If they cost more than this, we counted them as premium class.

1. Thermos King Flask - BEST CHOICE THERMOS 2022

A classic thermos that you can rely on all day long

Price class: Medium External diameter: 70 mm Diameter opening: 42 mm Height: 250 mm Weight: 360 grams Volume: 470 ml Heat retention capacity: 100 -> 82 °C after 4 hours at room temperature, 100 -> 90 °C after 1 hour at -10 °C

Thermos King Travel Mug 47cl

We've chosen the Thermos King Flask as our Best Choice. This thermos is a true classic, made in a factory established in 1929 by the Thermos company after which all thermos flasks are named. The Thermos King Flask, with its attractive retro style and metallic paint, is made from uncrushable stainless steel and managed to withstand both our leak and drop tests with flying colours.

The King Flask maintained high temperatures throughout both our outdoor and indoor testing, whilst the outside of the flask remained cool. The lid of the thermos is easy to use even for children and elderly people and can straightforwardly be removed and replaced even when wearing gloves. However, we felt that the opening could be larger to help with cleaning it. The Thermos King Flask is ideal for someone who wants an attractive thermos that delivers what it promises.

Very good heat retention capacity
Slightly narrow opening makes cleaning difficult

Price Comparison

Compare all prices
Ocado Logotype

Thermos Stainless King Travel Tumbler Blue 470ml

Amazon Logotype

Thermos 170271 Stainless King Travel Tumbler, Copper, 470 ml, 8.3 x 8.3 x 20 cm

Barnitts Logotype

Thermos Matt Black Stainless Steel King Travel Tumbler - 470ml


2. Stanley Adventure Vacuum Bottle

A useful thermos with a timeless design

Price class: Medium External diameter: 70 mm Diameter opening: 43 mm Height: 240 mm Weight: 513 grams Volume: 500 ml Heat retention capacity: 100 -> 81.1 °C after 4 hours at room temperature, 100 -> 88.7 °C after 1 hour at -10 °C

Stanley Classic Legendary Thermos 0.47L

The Stanley Adventure Vacuum Bottle is a substantial stainless-steel thermos with a classic style. While this thermos was invented and has been manufactured since 1913, its design doesn't seem to have aged for the thermos managed to keep liquid warm both during our indoor and outdoor tests. In addition to this it's leak proof, can tolerate being dropped and is straightforward to use even for younger children. The construction is simple with a screw top and a normal thermos mug. The only slight negative detail about this thermos is that the opening is a bit too small, which makes cleaning it somewhat difficult. The Stanley Adventure Vacuum Bottle is without a doubt a stylish, reliable and classic thermos for all outdoor trips.

Very good heat retention ability
Slightly difficult to clean

3. Twistshake Hot or Cold Bottle

A thermos for the changing bag that also fits well in a backpack for days out

Price class: Budget External diameter: 65 mm Diameter opening: 50 mm Volume: 420 ml Height: 22 cm Heat retention capacity: From 100°C to 78°C after 4 hours at room temperature

Twistshake Hot or Cold Insulated Bottle 420ml

This slim and neat thermos may be designed primarily for the baby changing bag, but that doesn’t mean it can’t accompany you on other adventures.

The thermos has a rubber cover, which makes it easy to grip and comfortable to hold. And being easy to hold is of course a big plus, especially given that it’s been designed to help you when you need to mix up a quick bowl of baby food. Mixing baby food is often associated with stress (hungry children aren’t usually happy to wait for their food) and at such moments it’s helpful if the thermos doesn’t easily slip out of your hand. With its slim design, this thermos fits snugly in the changing bag. The size also makes it very practical to carry with you – for example, it easily fits into side pockets on smaller backpacks. The Twistshake Hot or Cold has just one screw cap, without an additional pressure cap on the inside. Although this facilitates handling, it may also lead to the odd spill if you’re not careful, as the opening is 5 centimetres wide.

Heat retention is reasonable and the thermos comes in several different colours, making this an ideal thermos to take with you on a short trip. And for carrying hot (or cold) water with you to mix baby food or a meal replacement, it works fine.

Grip-friendlypractical screw capslim design that doesn’t take up much space
No inner lid

4. Hydro Flask Wide Mouth Flex

A thermos that will be your best friend on shorter trips

Price class: Medium External diameter: 70 mm Diameter opening: 58 mm Height: 200 mm Weight: 343 grams Volume: 532 ml Heat retention capacity: 100 -> 68.3 °C after 4 hours at room temperature, 100 -> 81.5 °C after 1 hour at -10 °C

Hydro Flask Wide Mouth Water Bottle 0.946L

The Hydro Flask Wide Mouth Flex is a small, lightweight and easy to manage thermos. Despite being made from stainless steel, the outside of the flask doesn't feel hot when filled with boiling liquids. The large opening makes it easy to clean compared to the other thermoses we tested. The lid has a handy rubber handle that's easy to get a grip of, even with cold, fumbling hands during a day on the ski slopes. The Wide Mouth Flex had no problems with our drop and leak testing. However, we did find the thermos to go cold relatively quickly, both in our indoor test and our outdoor test in winter temperatures. The Hydro Flask Wide Mouth Flex is therefore most suitable for shorter adventures or for your morning coffee on the way to work.

Practical lid with handle, generous opening facilitates cleaning
Mediocre heat retention capacity

5. Klean Kanteen Insulated Classic

A trendy flask for people on the go

Price class: Medium External diameter: 67 mm Diameter opening: 44 mm Height: 216 mm Weight: 258 grams Volume: 355 ml Heat retention capacity: 100 -> 67.8 °C after 4 hours at room temperature, 100 -> 83.5 °C after 1 hour at -10 °C

Klean Kanteen Classic Water Bottle 0.592L

Klean Kanteen is making a major investment in manufacturing water bottles and thermoses in stainless steel instead of plastic, with a view to reducing the environmental impact of their products. The lid on the Insulated Classic thermos is easy to use and doesn’t leak. The body of the flask doesn't get hot on the outside, but it did dent slightly during our drop testing. The thermos opening is rather small, which makes cleaning difficult, and the thermos also doesn't keep drinks hot for very long. However, the Insulated Classic gets bonus points for its innovative design and its striking colours. Above all, Klean Kanteen's Insulated Classic feels like a cool thermos that was primarily developed for city-dwellers who might a caffè latte in one hand and a laptop in the other. For this environment the thermos would be fine.

Fun design, ambitious environmental goals
Mediocre heat retention capacity, hard to clean, not impact resistant

6. Eva Solo To Go Cup

A simple, everyday thermos that is dishwasher-safe

Price class: Medium External diameter: 60 mm Diameter opening: 65 mm Height: 200 mm Weight: 275 grams Volume: 350 ml Heat retention capacity: 100 -> 54.2 °C after 4 hours at room temperature, 100 -> 75.2 °C after 1 hour at -10 °C

Eva Solo To Go Water Bottle 35cl

The Eva Solo To Go Cup is a smaller sized thermos made from stainless steel with a functional silicon click-open lid. This lid is great if you don't want to have to unscrew a cup, but also comes with a greater risk of leaking as if there's any remaining liquid in the lid, it may leak out later on. Despite the cup having a handy strap, the flask was a little bit difficult for our smaller children to open. However, the thermos is dishwasher-safe, which is unusual out of the flasks we tested and is a big plus point for anyone who doesn't like washing us their flask by hand. The thermos didn’t leak when laid on its side and didn’t break when we dropped on the ground. However, the outside did get a little warm when filled up with hot liquid and the thermos didn’t stay hot for very long. While the Eva Solo To Go Cup isn't something you'll want to rely on for a full day trip, it's fine as an easy-to-manage thermos to fill with coffee and shove in your bag when you're on the go, just as its name implies.

Practical carrying strap, dishwasher-safe
Heat retention capacity is very limited, slightly fiddly lid with some risk of leakage

Everything about thermoses

Whether it’s full of hot chocolate for a day out on the ski slopes, coffee for your commute or warming soup for a lunch while hiking - a thermos flask is useful in many different circumstances. The biggest advantage of a thermos is that you can always have a hot drink with you regardless of whether there are cafés or shops nearby. You save a lot of money by taking your own hot drinks with you from home.

There are currently a variety of different thermoses available to buy. Some have traditional screw cups and some have spouts to drink from. You can buy a thermos with a classical design made from grey stainless-steel, or you could choose one with an innovative shape and colourful patterns on the outside. If you have a lot of guests you could use a larger thermos jug, or you can use a smaller thermos that only contains only a single cupful of liquid if you want a hot drink during your commute.

In this test we tested relatively small, light thermoses that have capacities of around 500 ml. This size is easy to take with you and is suitable for either one or two people. All the thermoses are made from stainless steel, a tough and thoroughly tested material which is perfect for thermal flasks. We looked at the most popular models on the market, some of which are genuine classics which have been manufactured for several decades. While many of the thermoses available today are primarily intended to keep coffee hot during short walks in the park, if you want a thermos for this purpose you can pretty much buy any thermos you like. Most models can easily cope an easy task such as this. In our test, we pushed each model of thermos a little bit further. We wanted to find a thermos that could keep liquid hot during a long hike in the forest, that could thrive in winter conditions, that could tolerate being dropped on the ground, that is suitable to be used by children or someone wearing gloves and that would not leak into your rucksack. The ideal thermos also has to be easy to wash, ideally in a dishwasher, and should not consist of too many separate parts.

Our test showed that smaller and modern stainless-steel thermoses are generally very good. Ultimately, all of the thermoses we tested were satisfying products, and even the ones that didn't come out on top in our test were of relatively high quality. None of the thermoses broke during our test, and even if a few of them ended up with small dents, none of them leaked.

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