Best Thermos Flask in India - Reviews and Comparison 2021

The material of the flask is another crucial factor to consider as that decides the temperature retention. There is no shortage of the materials using which a flask can be made, but, amongst all, the double-walled stainless steel material has been proven to be the best—for example, plastic. There are manufacturers using plastic as thermal insulators. Due to being a bad insulator, plastic keeps the temperature intact only for a couple of hours. Also, it is fragile, and it is likely to break.

Metal flasks, especially stainless steel, is highly recommended due to their durability and features like resistant to corrosion, scratch-resistant, easy to clean and better heat retention. Moreover, indoor steel is capable of holding the vacuum isolation pressure inside the bottle.

Speaking of outer material, plastic is most common among manufacturers. It is lightweight and easy to carry. Some thermos flask has a metal outer casing as well. They offer solid construction and are corrosion-resistant too.

The best way to check a thermos flask's material is – a flask with an excellent thermal insulator will not get hot while pouring the hot beverage in it and won’t sweat when you pour a cold liquid inside.

Heat retention might have found the third spot, but this factor is no less important than the first two. After all, the factor defines the amount of time for which the flask can keep the drink hot or cold. A thermos flask made from the best material can retain temperature for one whole day!

Usually, a flask can retain temperature for as low as 4-5 hours and as high as 36 hours. The retention power can vary for hot and cold beverages. And typically, the capacity for retaining the temperature of a cold liquid is much higher than a hot beverage.

Get a flask with double-wall vacuum insulation as that prevents the conduction of heat. The reflective stainless steel interior prevents heat from escaping and maintains the temperature inside the thermos.

There are two types of insulation, i.e. vacuum and foam.

The vacuum insulation creates a vacuum in the inside wall and doesn’t let the heat transfer from the outside of the bottle. Moreover, there is no air; hence, the convection does not occur, and the temperature of the liquid is retained inside the bottle. On the other hand, in the foam insulation mechanism, the convection is prevented using foam. Foam doesn’t let air circulate easily; thereby, the heat cannot transfer from the outside of the bottle to the inside.

Thermos flask with vacuum insulation is preferred as it maintains the temperature for a longer time as compared to the flasks with foam insulation.

Vacuum insulated flask uses double-wall construction that creates a gap between the beverage and the bottle's exterior shell. This wall neither lets the heat or cool air escape from the flask nor enter it. So, the lid is the only medium for air to enter or escape. Hence, such a flask keeps your beverage hot or cold for long hours.

Durability is vital as you will not keep the flask in the cup holder of your car safely. There are chances that you will carry it for outdoor activities where it may accidentally fall and breakdown or get scratches. Similarly, if your flask is made using material that is not corrosion-free, its life will be over soon.

Basically, any flask which is not helping in retaining the temperature is not worth using. A thermos flask should be made of strong and durable materials keeping the vacuum intact and offering the best performance.

Stainless steel flasks are preferred as they are strong enough to hold the vacuum, withstands accidents or bumps for a long duration and are rust-free.

A good thermos flask has an insulated, strong and secure lid with a proper locking system that successfully prevents leakage from the bottle.

The lid should not easily come off, and at the same time, it should be easy to clean. Also, it should loosen and tighten easily while fitting the flask flawlessly. Thermoses that come with corks look attractive. However, they are often not as effective in preventing leakage. Screw caps keep in place and hence, often preferred.

The thermos flask must be made up using 100% food-grade materials. 304 food-grade stainless steel is considered the best material to make a flask as it is free of corrosion, BPA, and rust. Such material ensures whatever you are consuming is safe and free from chemicals or toxin elements. Moreover, the material is known for its durability and is also environmental-friendly.

We might have listed simple and classy looking flasks, but you can find beautifully painted and engraved images flasks for a bohemian or unique look. Such flasks feature vibrant colours, beautiful artwork and meet the purpose of those who want a break from monochrome looks. Moreover, there are touristy flasks, sports flasks, flasks decorated with funny images, and official RAF hip flasks.

Our top thermos flasks have copper coating as that helps in retaining heat. So, it is one of the essential things to consider when we talk about construction. Silicon powdered coating on the outside is another thing that should form part of a flask. Besides, the best thermos flasks are usually made with 304 food-grade stainless steel material.

Weight matters while buying a thermos flask because you have to carry it in your hands or a backpack. Also, you will hold it to pour liquid in the cup or drink directly from the nozzle. If it is a heavy flask, holding can be a bit cumbersome. Overall, a heavy thermos can be inconvenient in every manner.

The best flask is one that is lightweight and doesn’t take much space.

Not just flasks vary in shape and size, but their lids differ too. A flask can have a flip-open lid, narrow mouth, or a wide mouth lid with a cup-like cover. The narrow and flip-open top lets you drink directly from the bottle whereas, the wide mouth lid is about pouring your drink into the cup-like cover. In other words, you can use the lid/cover as a mug to drink your beverage conveniently. It is perfect for the outdoors and when you don’t want to carry an extra cup with you. Typically, a thermos cup is made using the same material as the flask to retain heat in much the same way.

Get a thermos flask or bottle which is easy to clean from inside. For this purpose, a flask with a wide mouth or adjustable opening is preferred as they offer easy cleaning. For a thermos bottle with a narrow mouth, you can use a soft bristle brush to get rid of the odour and stains.

There are various options to choose from when it comes to thermos flasks. They can be very cheap to surprisingly expensive. If you think that more price means that the flask is of higher quality, we would say think again because this is not always the case. A few cheaper flasks may function better than the higher-range flask. All-in-all, you can find a durable and well-performing thermos flask between ₹300 – ₹1500.

Any product coming from a manufacturer with a warranty proves to be reliable, even a thermos flask. Choose a flask coming with a reasonable warranty period, such as six months to 1 year. Moreover, if you are buying a flask online, it is hard to tell how well the flask will hold up despite reading the customer reviews. The warranty works there too, as you can send it back for a refund/exchange if it does not function as advertised.

• A flask with a carrying handle makes it easier to move around, especially if you are carrying a hot beverage in it.

• Look for a firm flask grip. Flasks with rubber grips or a powdered-coat finish are the best.

• If driving, choose a slim travel tape that fits into a cup holder for a car. 

• If you will take a thermos bottle while running or training, get the one with a carrying strap or clips on the bottle as they offer a comfortable grip.

• Flasks also come with carrying case to preventing leakage.