A good thermos flask will be able to hold your drink warm or cold for an entire day. It should be easy to pour, leakproof, travel-friendly and above all durable. Keeping these aspects in mind, we tried 7 of the best-selling thermos flasks in India to find the best suitable for different needs.
Two of the main aspects to consider when you are out to buy a thermos flask are capacity and design. When travelling by car, you have better flexibility as you needn’t carry around the flask in your backpack. In such cases, you can choose any capacity that suits your particular needs. But, if you are trekking or travelling by bus or train, weight matters. In such cases, it is better to opt for a 500 or 750-ml flask. Similarly, if you are carrying milk for children, a 300-500 ml thermos flask would be sufficient. But for hospital stays, it is better to opt for a thermos flask with more than 1-litre capacity so that a cup of coffee is always available for the patient and visitors.
Design is yet another important aspect to consider. Nowadays, you mostly get two types of flasks. The first is thermos bottles ( on the left in the above image). The other is the thermos flasks ( on the right in the above image) with the conventional design which has a wide mouth, an inner lid with flip open spout and an outer lid that doubles up as a cup. The former is more apt for carrying hot water. This design is the most optimal for preserving heat. But, on the flip side, as the mouth is narrow, you may find it difficult to clean, especially if you carry coffee, tea and such drinks which can stain the interiors.
Thermos flasks with conventional design are easier to clean, thanks to wider mouth. It is convenient as you often get a carry pouch and the lid acts as a cup. But, the flip-open spout often tends to get damaged within 1-2 years of use. Also, comparatively, it loses heat more quicker than the former design. Most of them are not really leakproof as claimed either.
Now, let us take a look at our top recommendations.
Our Top Recommendations
If you are looking for a thermos flask with a bottle design, then Milton Duo DLX is one of the best options to consider. It keeps water warm for 24 hours as promised. It is available in sizes ranging from 350 ml to 2.2 litres. Comparatively, it is more lightweight than other options of similar capacity. The 750 ml flask weighed just 376 gm. This makes it especially suitable for trekking and travel by public transport.
If you are looking for a thermos flask in conventional design, then Milton Thermosteel Flip Lid is a fairly good option. It is available in sizes ranging from 350 ml to 1 litre. As it comes with a carry bag, it is easier to handle and less likely to dent if its falls. It too keeps the water fairly warm for 24 hours as promised. A 750 ml flask weighs around 450 gm.
Table of Contents
- Our Top Recommendations
- How We Tested?
- Which Are The Best Thermos Flasks In India?
- Best Thermos Flasks In India
- How To Choose A Thermos Flask?
How We Tested?
We chose seven of the top-selling brands in India to try them out before recommending the best. Three of them have water bottle-like designs, while four have conventional flask designs. We weighed each option, as weight is an important aspect to consider for trekkers and those who often resort to public transport. Then, we filled each bottle to capacity with water boiled right out of a kettle. After that, we measured the temperature at 2-hour intervals till 12 hours lapsed, and finally after 24 hours. A graph was charted and except for one, options with the same design more or less showed the same results. What we infer is that design has an important implication when it comes to heat retention capacity.
When you pour boiling water into the thermos, the exteriors feel warm for a while. The lid was the warmest to touch indicating that most of the heat escaped through the top. As thermos bottles have narrow lids, lesser heat escapes compared to the ones with conventional design. Also, the flip-open spout in conventional flasks is not always airtight, resulting in higher heat leakage.
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Which Are The Best Thermos Flasks In India?
|Milton Duo DLX
|350, 500, 750ml,
1, 1.5, 1.8, 2, 2.2 L
|Pigeon Aqua Galaxy
|500, 750, 1000 ml
|Borosil Hydra Trek Flask
|500, 700, 850 ml
|Milton Thermosteel Flip Lid
|350, 500, 750, 1000 ml
|Milton Glassy Vacuum Flask
|350, 500, 750, 1000 ml
|Amazon Solimo Insulated Bottle
|500, 750, 1000 ml
|Borosil Hydra Thermo Flask
|350, 500, 750, 1000 ml
Best Thermos Flasks In India
Milton Duo DLX is the most expensive among the various options we tried. But, it is well worth it. It comes in a wide range of sizes. They are 350 ml, 500 ml, 750 ml, 1 litre, 1.5 litres, 1.8 litres, 2 litres and 2.2 litres. It is also available in three colour choices- red, blue and silver.
We tried the 750 ml option and it weighed just 376 gm, which was the lightest among the various options we tried. This makes it an apt choice for trekkers and those who rely often on public transport.
Flasks with flip-open spout lids often tend to leak after a while. In the case of Milton Duo DLX, you needn’t worry about it, as the lid closes shut making it absolutely leak-proof.
It is easy to pour from the bottle. However, as the mouth is narrow, you may not find it that easy to clean, especially after filling it with coffee or tea.
Coming to its heat retention capacity, we filled it with water boiled from a kettle. After 8 hours, the temperature dropped by around 16% and after 24 hours, it dropped by 36%. This proved to be the best performer. However, the difference between Milton Duo DLX and Pigeon Aqua Galaxy was very little and insignificant from a user perspective.
Even when filled with cold water, Milton Duo DLX performed the best. We filled ice-cold water at a temperature of 6.6 °C in the bottle. After 8 hours, the temperature was 9.1 °C and after 24 hours, it measured 12.8 °C, which was still pretty cold for consuming juices and other drinks.
Note that like most other options, it may dent when dropped from a height.
Pigeon Aqua Galaxy is one of the most budget-friendly thermos flasks among the ones we tried. It comes in 500 ml, 750 ml and 1000 ml capacities.
It too is leak-proof like Milton Duo DLX. Comparatively, it is taller than Milton Duo DLX and weighs a tad higher at 416 gm. While Milton has steel exteriors, Pigeon has a painted finish outside.
Its heat retention capacity is more or less similar to Milton Duo DLX. After 8 hours, hot water dropped the temperature by 16% and after 24 hours, it dropped by around 38%. So if you fill the bottle with hot tea immediately after preparation, it would still be warm enough after 24 hours. Cold water temperature raised from 6.1 °C to 12.6 °C after 24 hours, which is also satisfactory.
To clean the bottle, you may have to use a narrow brush like this as the mouth measures just around 3.5cm in diameter.
With red detailing, a handle loop and a black matte finish, Borosil Hydra Trek is the most stylish thermos flask that we tried. It comes in 500, 700 and 850 ml capacities.
The 700 ml bottle we tried weighed around 380 gm. Compared to the two former options, it has a wider mouth measuring 4cm in diameter too.
While all options come with a lid that has a plastic cap inside, in Borosil Hydra Trek, it is made of stainless steel. Also, it isn’t as thick as other options. We liked that water doesn’t come in contact with plastic in Borosil Hydra Trek. But, it had a huge negative too.
This resulted in a much higher heat loss compared to other options. In most other bottle flasks, the water temperature after 12 hours was around 73 °C while in Borosil Hydra Trek, it was just 63 °C. After 24 hours, water in Hydra Trek measured just 48 °C, while others measured around 60 °C. This means, after 24 hours, the water was just lukewarm. However, cold water retains temperature in a similar range to other options. Yet another disadvantage is that the washer in the lid has a tendency to come out often.
So while it does look attractive, it may not be the best option for keeping water hot for an extended duration. Comparative performance too isn’t the best. Overall, it may be an option we recommend when you want to take beverages to the gym or any short trip of 3-4 hour duration.
Milton Thermosteel Flip Lid is one of the best-selling thermos flasks in India. It comes in capacities of 350 ml, 500 ml, 750 ml and 1 litre. This type of flask is one of the best options for tea, milk, coffee and other cold beverages as it comes with a cup and is easier to clean.
The 750 ml flask weighs almost 450 gm. It comes with a bag that makes it easy to carry and also protects against dents in case of falls. In fact, if it falls without the bag in it and the corner hits the floor, it will dent.
Its heat retention capacity is almost at par with other thermos flasks of similar design. We poured hot water measuring 95.3 °C and by the end of 24 hours, it measured around 56.4 °C, which meant a drop of around 41%. Cold water measuring 5.5 °C measured around 12.2 °C after 24 hours.
As it has a wider mouth, it is comparatively easier to clean. But a drawback with these kinds of flip-open spouts is that it has a high tendency to leak after a while.
Available in three different colours, Milton Glassy comes in capacities of 350 ml, 500 ml, 750 ml and 1 litre. It too comes with a carry bag to protect against dents.
The main difference between Milton Glassy and the former option is that it has a lid which is like a cup with a handle. This makes it easier to take a quick sip of warm water on the go.
The flip-open spout is similar to what you see in Milton Thermosteel Flip Lid Flask. Initially, it did not leak. But, after dropping it once on the floor, it started leaking when you vehemently shake the bottle.
To test the performance, we poured water measuring 95.6 °C and it was 76 °C after 8 hours and 56.1 °C after 24 hours, which meant a 41% drop in temperature after 24 hours. Even then, it was fairly warm for a coffee or tea. Cold water measuring 5.5 °C was about 12.8 °C after 24 hours, which is also satisfactory.
The flask is fairly easy to clean, thanks to its wide mouth. But, as mentioned earlier, it has a tendency to leak.
Amazon Solimo thermos flask is available in capacities of 500 ml, 750 ml and 1 litre. It comes with a carry bag. However, the bag’s quality doesn’t seem as good as what comes with the Milton Thermosteel flask. The 750 ml flask weighed about 464 gm.
We noticed that the inner cap and outer lid seem a bit out of alignment. So you need to be careful while closing the lids, or else it may leak. However, once you properly close it, the lids are almost leakproof. We dropped the bottle from a height and though it was dented, the spout did not leak.
It retains heat pretty efficiently. After 8 hours, the temperature of the hot water we filled dropped by 18.5% and after 24 hours, it dropped by around 39%. Cold water of 5.6 °C was around 12.3 °C in 24 hours.
Price-wise, it is fairly competitive compared to Milton, making it an apt choice to consider.
Borosil Hydra Thermo vacuum flask is yet another top seller in India. It comes in capacities of 350 ml, 500 ml, 750 ml and 1 litre. You get a jacket for the flask which protects it from dents and makes it easy to carry.
The 750 ml thermos flask weighed 485 gm and the 1-litre flask weighed 543 gm, which was the heaviest among all the options we tried.
Compared to other options, we found Borosil Hydra a lot more prone to leaks. We had in fact personally bought a flask a few months back and returned it because it was leaking.
When it comes to retaining heat, the Borosil Hydra Thermo flask is almost at par with the other options. Water temperature by 20% in 8 hours and by 41% in 24 hours. The cold water temperature drop was also at par with the rest of the options.
Price-wise, it was the least expensive among the flask-type models.
How To Choose A Thermos Flask?
First and foremost aspect you need to consider is the type of flask- whether you need a conventional flask or a thermos bottle. As mentioned in the beginning, both has its own set of advantages and disadvantages. Thermos bottles are lighter, leakproof and have better heat retention. But, they are more difficult to clean. Thermos flasks on the other hand are easier to use as they come with a cup. But, they are often not leak proof. Its heat retention is marginally lesser than thermos bottles too.
Capacity is yet another important aspect you need to think of when buying a thermos flask. A 2 litre flask is apt for homes in cold regions and for hospital stay. A 1 litre thermos would be apt for one-day travels, while a smaller 300-500 ml bottle would be apt for carrying food/water for children.
Heat retention is of course one of the major aspects that determines the functionality of a thermos flask. Most thermos bottles and flasks lose about 20% of heat in first 12 hours and 30% of heat in the first 24 hours. So, if you pour boiling water in the flask, it will still be fairly hot after 24 hours.
From testing various options, we find most thermos bottles have a similar range of heat retention and likewise for thermos flasks. What we found is that after 24 hours, water in thermos flasks is generally 2-4 °C colder than water in thermos bottles.
Yet another interesting observation was that thermos bottles and flask lose most of the heat from the lid. Hence, having a thick lid is paramount. This is one of the main reasons why Borosil Hydra Trek loses heat quicker than other options.
Ease of Cleaning
Wide mouth is a key factor that determines the ease of cleaning a thermos flask. Generally, thermos bottles have narrow mouth than thermos flasks. This makes thermos bottles more difficult to clean. Hence, it is better to use them just for carrying hot water. For beverages, it is better to opt for thermos flasks, which are easier to clean.