Last updated: August 24, 2021

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You want to have a warm tea with you when skiing in winter? No problem with the insulated bottle. You want a cool drink while sunbathing on the beach? No problem with the insulated bottle. Of course, each bottle has different strengths. To find out which features the perfect vacuum flask must have for you, you should take a closer look at our vacuum flask test 2022.

Here we have listed the best bottles with insulating function for you and compared them with each other. Of course, we also answer questions about how a thermos bottle works, how much it should ideally cost and how long an insulated bottle will keep your drink hot or cold.


  • Insulated bottles with a drinking cap, insulated bottles with a bottle cap and insulated bottles with a cup are all available to you when choosing an insulated bottle. Depending on your preferences and intended use, you should choose the most suitable model.
  • Key purchase criteria such as a warming and cooling function, the volume, the weight, the dimensions and the design play an important role in the decision-making process.
  • You should consider the materials used especially if you value robust, dishwasher-safe and BPA-free drinking containers.

The Best Insulated Bottle: Our Picks

Shopping Guide

When is it worth buying an insulated bottle?

There are many reasons for buying an insulated bottle . One of the most important reasons is that thanks to an insulated bottle you can enjoy hot or chilled drinks at any place and at any time.

Sometimes there is no way to prepare or buy hot drinks. This argument is especially decisive if you are on the road a lot and are looking for a thermos bottle for hiking, camping or travelling, for example. Another reason to buy a thermos is that it saves you a lot of money. Instead of buying expensive drinks on the road every day, you can prepare your favourite drink cheaply at home and then take it to work, school or sports.

In addition, thermos bottles are very environmentally friendly and sustainable, as they can be used over and over again for many years. There is no unnecessary waste as with the one-time use of coffee-to-go cups made of cardboard or plastic. Another argument for coffee and tea lovers is that they can enjoy their favourite teas or coffees everywhere and every day thanks to an insulated bottle.

An insulated bottle can also be used flexibly for many other drinks. It can be used to transport refreshing water for sports, mulled wine at Christmas time, apple juice for kindergarten or cool wine for a picnic in summer. Here is a clear summary of the reasons for buying an insulated bottle:

  • Enjoy hot and cold drinks anywhere, anytime
  • Saves costs
  • Environmentally friendly
  • Suitable for many drinks

How do I find a thermos bottle without harmful substances?

Thermos bottles can contain harmful substances such as BPA, which can be very dangerous. Therefore, before buying a thermos bottle, you should look into the issue. Many manufacturers state in the product description whether their bottles contain harmful substances. On this page, we will only introduce you to insulated bottles that are free of the harmful substance BPA. If you are interested in other components of your thermos bottle, we recommend the respective eco-test results.

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An insulated bottle can also be used flexibly for many other drinks.

Which drinks is an insulated bottle not suitable for?

Basically, an insulated bottle is not suitable for carbonated drinks. Carbon dioxide can damage the bottle and make it leaky. Moreover, insulated bottles should also not be used to keep milk and baby food warm. This can cause dangerous germs.

How does a thermos bottle work?

Inside an insulated bottle there are two walls, which nowadays are usually made of stainless steel. Between these walls, in turn, there is a vacuum, i.e. an airless cavity. It ensures that heat conduction is prevented.

Did you know that the functional principle of the vacuum is also used in thermal solar systems? There are vacuum collectors that are used to generate energy.

Thus, the temperature of the liquid in the vacuum bottle is not changed by the temperature of the environment outside the vacuum bottle and the drink remains cold or hot. In addition, the reflective surface of the inside of the thermos bottle promotes insulating properties.

An insulated bottle is suitable for both hot and cold drinks.

How long does a thermos bottle keep hot and cold?

Not every insulated bottle can keep drinks hot or cold for the same amount of time. How long an insulated bottle keeps warm depends on various factors and can vary greatly depending on the model. A good thermos bottle will keep drinks warm for at least six to eight hours. On this page you can also see how long the individual models presented keep hot and cold.

Are there still insulated bottles with glass inserts?

When the vacuum flask was invented in 1893, the inner insulating walls were made of glass. For many years, insulated bottles were sold with glass flasks. Nowadays, there are almost no insulated bottles with glass inserts. Instead, the inside of a thermos bottle is made of stainless steel.

Did you know that the first vacuum vessel was used as early as 1874? It was used by James Dewar for chemical experiments.

Stainless steel is much more robust and less dangerous. With an insulated bottle with a glass flask, there is a danger that the inside will quickly break if it is dropped or transported. Since insulated bottles are usually used for travelling, it is very important that they are very sturdy and cannot break.

In addition, the glass can be destroyed and shattered when cleaning an insulated bottle with a glass flask. That is why nowadays almost all thermos bottles are made of stainless steel.

Decision: What types of vacuum flasks are there and which is the right one for you?

In general, you can distinguish between three different types of thermos bottles:

  • Insulated bottles with drinking cap
  • Insulated bottle with bottle cap
  • Insulated bottles with cup

The closure is different for each of these types, which results in different advantages and disadvantages. Depending on what you need a thermos for and which features are particularly important to you, one of the above types of thermos is the right one for you.

For example, some insulated bottles are better suited for children and other thermoses are particularly recommended for the workplace. In the following text, we will explain all three types of vacuum flasks in detail, show you the advantages and disadvantages and help you to find a suitable vacuum flask.

For whom is an insulated bottle with a drinking cap best suited and what are the advantages and disadvantages?

Because they are so uncomplicated, insulated bottles with a drinking cap are particularly suitable for sports, school or kindergarten. Thanks to their drinking cap, you can drink quickly and easily from this type of insulating bottle. It is particularly suitable for children, as there is no risk of burning when pouring. In addition, they are available in many beautiful designs for children, such as pirates or princesses.

  • Uncomplicated
  • Closure very suitable for children
  • Space-saving
  • Available in beautiful children's designs
  • Only suitable for one person
  • closure is made of plasticAvailable only in 350ml to 750ml sizes

Other advantages of a thermos bottle with a drinking cap are its robustness and compact size. This makes it easy to carry in a child's backpack or sports bag. If you are looking for an insulated bottle for just one person that can hold 350 ml to 75 0ml of liquid, the insulated bottle with drinking cap is a very good choice. However, if you don't like plastic, the insulated bottle with bottle cap might be more suitable for you.

Who is a thermos bottle with a bottle cap best suited for and what are the advantages and disadvantages?

Bottle-top thermoses are a great choice for taking hot or cold drinks to work, university or sports because of their design and simplicity. Insulated bottles with bottle tops are relatively new and are becoming more and more popular because of their stylish, classy and fashionable design. They come in many different colours such as black, pink, green and silver. They are very robust, space-saving and available in 500 ml and 750 ml sizes. Therefore, they are more suitable for one person.

  • Good for keeping drinks hot or cold during sports
  • Uncomplicated
  • Stylish design
  • No plastic tasteSpace-saving
  • Usually only available for 500 ml and 750 ml
  • Closure not suitable for very small children
  • Only offered by a few manufacturers

In addition, they are particularly suitable for people who do not like plastic closures and plastic cups, as the closure is made of stainless steel. They are also usually free of the harmful substance BPA. However, if you are looking for a drinking bottle for small children or like a wider choice of manufacturers and sizes, an insulated bottle with a drinking cap or cup might be more suitable for you.

Who is an insulated bottle with a mug best for and what are the advantages and disadvantages?

If you are looking for a large insulated bottle for work, older children or outdoor activities such as camping and hiking, the insulated bottle with cup is a very good choice. This type of vacuum flask is the most common, is offered by many different manufacturers and comes in different varieties. The most common for this type of thermos bottle are the click cap and the screw cap.

The difference to the insulated bottles already presented is that you do not drink directly from the bottle, but from a cup. This has many advantages. When you buy an insulated bottle with a cup, you get two products in one.

In addition, you can use the mug that comes with the insulated bottle to warm your hands in cold temperatures. Both can be very useful if you are looking for an insulated bottle for travelling, camping or outdoor activities.

  • Hot or chilled drinks for several people
  • 2-in-1 product
  • Available in many different sizes
  • Additional hand warming on the mug
  • Takes up more space than other vacuum flasks
  • Less suitable for small children as risk of burns when pouring
  • Mug needs to be rinsed out

In addition, insulated bottles with mugs are especially good for keeping drinks warm for several people, as they come in many different sizes. Therefore, you can use one bottle for your whole family or offer coffee to your colleagues at work, for example. However, if you are looking for a space-saving bottle for small children, a thermos bottle with a drinking cap is more recommended.

Buying criteria: Use these factors to compare and evaluate vacuum flasks

In the following, we would like to explain to you which criteria you can use to compare and evaluate thermos flasks. This will make it easier for you to find the ideal vacuum flask for your needs. In summary, these are:

  • Keep tight
  • Keep warm and keep cold function
  • Volume
  • Weight and dimensions
  • Design
  • Dishwasher safe
  • BPA-free
  • Warranty
  • Material
  • Robustness
  • Spare parts available

In the following paragraphs you can read about the individual purchase criteria and how you can classify them. Tip: Take a look at our vacuum flask comparison table. In this easy-to-understand overview, we have compared the currently most important thermos flasks with each other on the basis of the insulated flasks presented here.

Keeping it tight

One of the most important features of an insulated bottle is that it keeps tight. Unfortunately, there are some thermos bottles that leak. It can be very annoying if your coffee or tea leaks in your bag and important things get damaged. Therefore, when buying an insulated bottle, you should make sure that it is very well made and inform yourself well before buying. You can look at reviews and test results.

You should also test a thermos bottle at home before you take it on the road for the first time. This way you can avoid unpleasant surprises. To test your insulated bottle, we recommend filling it with hot water and then holding it upside down over a sink and shaking it. If it stays tight, it has passed the first test. To make sure it really doesn't leak, you should do this test a second time after a few hours.

Before using the insulated bottle for travelling, a leak test should be carried out to check the tightness of the bottle.

Keep warm and keep cold function

Another very important feature of an insulated bottle is that it keeps drinks hot or cold for as long as possible. Unfortunately, in this case there are also some models that cannot insulate liquids for very long. First of all, you should look at the manufacturer's specifications for the hot and cold holding time. In many cases, these guidelines are correct.

In our table, you can see an overview of the warm and cold storage times of different models in a clear comparison. We also recommend that you look for testimonials from people who have bought the vacuum flask to find out whether the flask can actually keep drinks warm for as long as promised.


Insulated bottles can have very different capacities. Some thermoses can hold 350 ml and others up to 2000 ml. Since you will probably want to use your vacuum flask for many years, you should think about what the optimal size is for you before buying.

To find the right size, the following questions can help you: Are you looking for an insulated bottle for one person or for several? Do you want to buy an insulated bottle for a child or an adult? Will the thermos need to be transported and carried for a long time?

Are you looking for an insulated bottle for whole day trips or to have warm or chilled drinks with you for only a few hours? A smaller vacuum flask is easier to carry. A larger insulated bottle, on the other hand, can be used for several people and thanks to it you can enjoy chilled or hot drinks all day long.

Weight and dimensions

Insulated bottles can vary greatly in size and weight. It can happen that bottles of the same size weigh different amounts. Especially if you carry your thermos a lot and want to take it with you, for example, when hiking or travelling, the weight of the bottle is a very decisive criterion. Once you have decided on a capacity, you should compare the weights of the respective bottles and look for the lightest thermos.


Insulated bottles come in many different colours and designs. Since most thermos bottles are made of stainless steel, the colour silver is very common. Silver is a classic and simple colour and goes with many activities and occasions. Therefore, you can't really go wrong if you choose a silver thermos. There are also many single-colour versions of vacuum flasks.

The colour selection is so large that you are guaranteed to find a thermos in your favourite colour. Black, green, blue and pink are very popular. There are also unusual and glamorous colours like gold and rose gold. If you are looking for an insulated bottle for a child, the colour of the insulated bottle is a particularly important criterion.

Children will be delighted with a thermos in their favourite colour or an insulated bottle with a child's pattern. For girls, there are insulated bottles in pink with princesses, unicorns, horses and mermaids. For boys, there are thermos bottles with cars and football. There are also thermos bottles with the main characters from popular children's programmes like Vicky the Viking or Maya the Bee, and there are many other models with cute animals like polar bears, foxes and cows.

Dishwasher safe

If you have a dishwasher and don't want to spend a lot of time cleaning your vacuum flask, it is very important that your flask is dishwasher safe. Not every thermos is suitable for washing in a dishwasher. Therefore, before you buy, you should check if there is a dishwasher-safe logo on the bottle or if the manufacturer states this online or on the product packaging.


Bisphenol A, or BPA for short, is a hormonal pollutant. It is hazardous to health and we therefore recommend that you buy an insulated bottle that does not contain BPA. Since BPA has only been banned in Germany in connection with baby bottles, some thermos bottles still contain this harmful substance. Therefore, when buying a thermos bottle, make sure that it says BPA-free on the packaging or online.


Some thermos bottles have a longer guarantee than the legally required guarantee. The legal guarantee is two years. Since an insulated bottle is a product that you usually keep for many years, such an additional guarantee is an advantage. In addition, a long guarantee is often a sign of a high-quality product.


Nowadays, almost all vacuum flasks are made of stainless steel. Thermoses with glass flasks are almost non-existent. You can find more details in the advice section. Stainless steel is a very good and robust material and ideally suited for vacuum flasks.

However, nowadays there are only a few insulated bottles with plastic exteriors. They are not as good as bottles made of stainless steel and often do not keep as tightly. That is why we only present stainless steel models on our homepage.

Unlike stainless steel, glass can break quickly.


Since an insulated bottle can fall down during frequent use, it is important that it is as robust as possible. Some insulated bottles are more robust than others. Especially if you are looking for an insulated bottle for children, it may fall down more often in the future.

It is therefore very important to choose a thermos that is not immediately dented, scratched or chipped. An insulated bottle made of stainless steel is less sensitive than a thermos made of plastic. That's why you should always buy a stainless steel thermos.

Repurchasable spare parts

Since an insulated bottle is a product that lasts for years, it may be important for you to be able to buy spare parts for the drinking bottle individually. Unfortunately, it can happen that individual parts of the vacuum flask such as caps, cups or the body of the flask itself get lost or broken or wear out too much.

If the remaining parts are still in good condition, it is cheaper and more environmentally friendly to buy only the individual parts. Many brand manufacturers offer this. Especially if you are looking for a thermos bottle for children, it can happen that drinking caps wear out more quickly or individual parts get lost. In this case, it is a great advantage to be able to buy spare parts quickly and easily.

Facts worth knowing about insulated bottles

How do you clean an insulated bottle?

Nowadays, many thermos flasks are conveniently dishwasher-safe and can be washed in the dishwasher without any problems. If you choose a non-dishwasher-safe model or don't have a dishwasher, we have a few more helpful tips for you on how to clean your insulated bottle.

Generally, it's enough to clean your bottle with a brush and washing-up liquid. From time to time, however, it is recommended to clean the bottle even more thoroughly. You can buy special cleaning tablets for insulated bottles, which are very effective.

However, as these tablets are very expensive, you can just as well buy cheap denture cleaning tablets from the drugstore or order them online and use them to clean your thermos bottle. Bottles can also be cleaned with baking soda. To do this, pour a packet of baking soda and hot water into your bottle and leave it to soak for 30 minutes.

Insulated bottles can be cleaned quickly and easily with baking soda and hot water.

What should I consider when buying an insulated bottle with engraving?

A printed or engraved thermos is a very nice and personal gift and you can buy them online from various suppliers. However, you should make sure that you really buy a high-quality thermos that will last a long time and will not leak.

Unfortunately, this is not the case with all engraved thermos bottles. Therefore, you should look at reviews of the individual models beforehand. Thermoses from brand manufacturers with good reviews are preferable in this case.

Image source: / Arunas Naujokas