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Enjoy your favourite beverages piping hot while on the go with our range of premium thermoflasks.

Buy Thermoflasks Online in India|Nestasia

Introduction of Thermoflasks

A vacuum flask, a hot water flask, or a thermoflask is a type of storage container that keeps a material's temperature constant for a longer period of time unlike when it is kept out in the air. By keeping a consistent temperature and preventing the possibility of off-taste and odour, the hot water flask is primarily intended to lengthen the liquid's storage term. It is a device designed to hold the temperature of hot liquids like soup, milk, tea, or coffee for a longer length of time. Vacuum flasks are composed of double-walled, strong glass that has been coated in highly reflective nickel/cadmium. Before being sealed from the end, vacuum is applied to the vacuum flasks. 

The vacuum between the hot water flask's two walls serves as an excellent insulator, preventing heat from dispersing even for long periods of time. Thermos, tea thermos, thermosteel flask, etc. are now available in double-walled, unbreakable stainless steel bottles for increased longevity and durability. The thermoflasks are produced in both the organised and unorganised sectors. Nonetheless, the testing of vacuum flasks from the organised sector was scheduled for comparison by us so that we could test and provide only the best to our customers.

Over extended periods of time, thermo flasks/ thermosteel flask keep hot drinks hot and cold liquids cold. It is made out of a glass container or steel container with two walls. A metal or plastic cover is placed around the glass jar to prevent damage. As there is a vacuum in the area between the walls, less heat is lost by conduction and convection. Both the inside and exterior surfaces of the inner wall are silvered (shining). The reflective surfaces minimise radiation-related heat loss. The mouth of the vessel is sealed with an insulating stopper (cork). The vessel is stored on top of a cork cushion or in a small flask for tea. As a result, it has thermal insulation. As a result, heat cannot readily escape or enter the flask, causing hot liquids to stay hot and cold liquids to stay cold.

Up until recently, a vacuum thermos flask bottle filled with hot tea or coffee was typically brought along on a lengthy trip in a vehicle or coach. They were the companions of the traveller. But, the vacuum flask or thermos flask bottle was developed to maintain the cold. In the days before refrigeration, the vacuum flask or thermos flask bottle was a godsend, used by vendors to keep ice cream cold and fresh fish cool, but even when refrigerators became standard, the vacuum flask didn't lose its significance. Flasks/ thermos flask bottles of various sizes are still used to convey food and drink, as well as valuable cargo like plasma and even human organs for transplant, after the interior's fragile glass was replaced in 1978 by stainless steel.

But, the vacuum thermosflask's technology is now most commonly associated with the insulated cups we use to transport takeout coffee, which eliminates the need to dispose of single-use cardboard cups in landfills. Yet the ability to sip a hot beverage after a strenuous hike on top of a remote mountain is still one of life's minor pleasures. a symbol of comfort and science.

Collection of Thermoflasks Available at Nestasia

Our assortment of thermoflasks includes-

  • Smart Thermos
  • Smart Sleek Flask
  • Large Vacuum Flask
  • Stainless Steel Flask, 
  • Stainless Steel Water Bottle
  • Matte Thermos
  • Double Walled Travel Tumblers

Thermosteel Flask

The category of thermosteel flask/thermos flask bottle at Nestasia is divided into 2 sub-categories:

  1. Hot/cold water flask: including thermoflasks, hot water thermos, thermosteel flask, steel flask, steel thermos, small thermos flask, stainless steel flask, steel thermos flask- all without strainers or removable strainers.
  2. Tea thermos: thermos water bottle with strainer, small flask for tea, mini flask for tea or the range of hot water flask with strainers.

Cold/Hot Water Flask

The vacuum insulated thermos water bottle flask for tea or hot water flask was created specifically for this reason, so if you are wondering how to keep your water cool on a hot summer day while you are outside, look no further. These stainless flask/ water bottles/ hot water flasks are designed so that their interiors are totally isolated from the outside environment.

Insulated bottles or hot water thermos include two chambers: one holds water, and the other one is surrounded by vacuum to keep the inside from contacting the outside world. Hence, your water will stay cold all day in the water thermos.

An insulated thermos water bottle or hot water thermos/ hot water flask often weighs more than regular water bottles because of the way it is made. During the sweltering heat, a decent insulated water bottle may be your buddy. However, these are more expensive than other kinds of bottles, so for some people, the price may be the determining factor. Having said that, a one-time purchase in an insulated bottle or hot water thermos is well taken into account when you look into issues like the significance of being hydrated or the impact of single-use plastic bottles on the environment.

Tea Thermos

The first piece of equipment to keep tea hot is a tea thermos/ thermosteel flask. You can take your hot tea when travelling or at work with this insulated bottle, small thermos flask, or a mini flask for tea, which is made of glass or stainless steel. You must consider a number of factors in order to pick the right tea thermos. Significant factors are the material utilised, the weight, and the capacity. To enjoy your teas and hot beverages, pick a thermos water bottle flask for tea/ steel thermos/ small flask for tea with a design you like.

For those who enjoy tea, coffee, or herbal tea, a tea thermos/ steel thermos is one of the most important items. Take your favourite beverages with you everywhere you go with this isothermal bottle or a mini flask for tea. Unlike a gourd or a traditional water bottle, a small flask for tea allows you to maintain the temperature of your tea.

The tea thermos is indispensable when travelling and useful for consuming your plant-based beverage at work. Your insulated bottle may be safely stored in your bag. The tea thermos's lid keeps your drink from leaking while you're travelling.

Several materials can be used to make a tea thermos or an insulated bottle, small thermos flask, or a mini flask for tea. Stainless steel was our choice because it is frequently the material used for this kind of product. A thermos made of stainless steel is particularly resilient. Hence, steel bottles are ideal for travel or travel that involves a danger of shock. Furthermore, a stainless steel tea thermos is lightweight and simple to clean. The stainless steel thermos container will be absolutely devoid of the flavours of the various teas used after washing.

Sizes of Thermoflasks available at Nestasia

Nestasia’s thermo flasks, water thermos range from 23 cm to 28 cm height with 6.5cm diameter and capacities of 500-800ml. We have stainless steel water bottles of 1000ml capacity for daily activities like travelling to office, school or college, as well as hiking, camping. 

How To Use Thermoflasks?

Although the majority of our products may be used on the top rack of a dishwasher, they do prefer a kinder approach. Hand cleaning is advised to keep your thermo flask/ water thermos in peak condition because dishwashers use stronger detergents and hotter water that could degrade the look of your thermo flask.

Wash all parts of the thermos water bottle thoroughly before first use with warm soapy water, rinse and allow time to dry. However, it's advised not to use abrasive cleaners or cloths as they may dull the finish, or use bleach or cleaners containing chlorine on any part of your thermo flask/ thermos water bottle. Immersing or soaking it in water for prolonged periods of time is never a good idea as residual contents may become trapped between product components.

Our goal is for you to view your Nestasia's thermoflask/ steel thermos flask as your dependable travel buddy, ready to accompany you wherever you go. Yet, you must treat it well if you want it to remain your buddy. For best thermal efficiency, fill the steel thermos flask with hot or cold water immediately before use, then attach the lid and let it stand for five to ten minutes. Please don't overfill the flask; allow room for the lid at the top to prevent spillage. Wash the container as soon as you can after each usage if the contents have been left in it for more than 24 hours.

Before using your stainless steel flask for the first time, please make sure to fully rinse it with clean water after cleaning it with warm water and dishwashing liquid. Steam and hot liquids may be dangerous! While filling, make sure the flask is level, kept at arm's length, and away from children and pets. You should also avoid looking straight into the flask while filling. Pre-cool your stainless steel flask by filling it with cold water for chilled drinks and pre-heat it by filling it with warm water for hot beverages to get the best results. Rinse your flask with warm water if it hasn't been used in a while.  If your flask has not been used for some time, rinse with warm water to remove any residual odour. 

Here are some pointers for keeping your Thermo flask bottle clean and prepared for use:

  • After each use, wash your bottle by hand with warm water and a non-abrasive dish soap. Bottle brushes help get into the corners properly. Avoid using cleaning products that include strong chemicals like chlorine or bleach since they might damage the container. Now, you have the choice of washing your bottle in the dishwasher. Lids are placed on the top rack!
  • If your thermo flask has an O-ring, remove the O-rings from the lid and soak it in a 50/50 mixture of water and vinegar for a thorough cleaning. Pull the tab carefully to remove your huge O-rings. Use a toothpick, an unfurled paper clip, or a fork to carefully pry the Little O-ring from the drinking spout cap. Use the flat side of a toothpick to gently press the replacement O-Rings back into place after placing them flat side down into the exposed locations. Make sure the silicone O-Rings are installed on your lid by checking it. To keep the cold inside, the O-Rings will form an airtight seal.
  • Prior to reassembling after cleaning, make sure that every component is thoroughly dry.

Why choose Nestasia to buy thermoflasks?

Craftsmanship and finish

Thermoflasks should be produced using proper manufacturing procedures. They should not have any manufacturing flaws, such as a wobbling bottom, jagged edges, an uneven neck and brim, or an unintended shape or size, and that’s what Nestasia is the most careful of. All of our flasks have excellent construction and finishing, with the mouths of all glass-type flasks having a smooth finish to avoid any sharp edges. The construction and polish of our stainless steel flasks are also aesthetically pleasing. All flasks in the stainless steel category can easily fit in lunch bags, making them easier to transport.

Leak Proof

At Nestasia, we have fabricated an experiment to check whether all our flasks are leak proof. In this experiment, the vacuum flasks were half-filled with cold water and secured with the stopper. They were then shaken vertically for one minute. The test's criterion required that there be no flask leaking either during or following the test. All of the flasks we evaluated were confirmed to be leak-free and hence passed the test.

Heat Storage

According to the Indian Specifications, all the different types of vacuum thermoflasks must pass the tests to determine their ability to retain heat after 1, 5, and 24 hours in various degrees of temperatures, both hot and cold. As a result, some of the superior quality flasks survive the test; Nestasia’s flasks are undeniably amongst them. At Nestasia, we have ensured all our thermoflasks have passed the test to deliver the best for you.


In order to facilitate easy handling and prevent loss or damage during transportation and storage, our thermo flasks are packaged carefully. The flasks are all securely wrapped in sturdy paperboard boxes.

Frequently Asked Questions

Is thermoflask and hydro flask the same?

A thermoflask and a hydro flask, both are well-insulated bottles that offer the luxury of very cold, chilled drinks or a warm beverage like tea or coffee- saviors when it comes to a long trip, hiking or camping. So, if one's about to choose a new stainless steel water bottle, it's essential to buy one that's durable and reliable. Crafted from high-quality stainless steel, thermoflasks and hydro flasks are constructed with double-wall vacuum-insulation. Both BPA-free flasks have an inner wall and an outer wall with a vacuum in the middle. Both of them are non-slippery, and have a wide mouth-filling. But what makes them different is the leak proof attribute. The thermoflask comes with a leak proof straw lid, so now you can walk and have a sip of freshly poured juice or tea which the hydro flask doesn't allow.

What is a thermoflask?

Thermoflasks from Nestasia's collection are stainless steel vessels that keep hot and cold liquids hot or cold for long hours. They consist of a glass vessel, enclosed by a metal cover for protection against damage. It's thermally insulated and hence, the heat doesn't leave or enter easily and hot liquids remain hot while cold liquids remain cold inside the thermos. 

Is thermoflask good for hot water?

Nestasia's premium quality stainless steel, BPA-free thermoflask keeps beverages hot and cold for up to 12-24 hours with double-wall vacuum insulation. The insulated water bottles or thermoflask at Nestasia are of a convenient size that fits in most cup holders, backpack pockets, and in your hand when adventure calls if one's planning to store hot water during the journey. 

Can I use thermoflask for coffee?

The assortment of thermoflask at Nestasia includes stainless steel flasks with and without strainers, both of which are absolutely perfect to take coffee hot or iced in them. A reliable thermos will keep the beverage at its ideal temperature for hours, and that's what Nestasia has ideated while making the thermos. The leak proof, handy thermoses are crafted keeping in mind the century-old vacuum technology, which was originally invented to keep liquids cold or hot, especially for populations of campers to commuters. 

How do I choose a thermoflask?

Mostly, the criteria to choose a thermoflask depends on the purposes for which you want to buy a new one. However, our stainless steel thermal flasks are one of the great choices if one's looking for a thermos that can keep the liquid hot or cold for up to 24 hours. The flasks are also leakproof, BPA free,  and live to the assurance of premium quality material, durability, and proper insulation. They also come with secure and effective lids which can also be used as cups while serving.

Which thermos keeps tea hot the longest?

Thermos, made of 304 rust-proof stainless steel, ranging from 500-800ml capacity, 100% leakproof, can keep the tea or any other liquid hot or cold for upto 24 hours which is recorded to be the longest period of time. Nestasia's thermosteel flask has passed this test and is successfully qualified to be your travel partner as well as a companion for going to office or college, without worrying about your favourite cup of tea. The lid can be used as a cup so you can take a sip while journeying.

How long will tea stay hot in a thermos?

Our vacuum-insulated, stainless steel thermos is tested to keep the liquids hot upto 24 hours. While a common range one can find while searching for thermoflask online is somewhere from 5 to 12 hours, Nestasia's thermoses can successfully guarantee a period of time higher than that, if not exactly 24 hours.

Can a stainless steel thermos go in the dishwasher?

Our thermos is made of stainless steel, an alloy that makes it dishwasher-safe and rust-proof. But it's still recommended to wash the thermos by hand to keep the beautiful, shining finish looking great for a longer time with any cleaner which doesn't contain bleach.

What materials are commonly used in a thermos?

The excellent quality thermos built at Nestasia is made of stainless steel. One of the most common materials used in a thermos is stainless steel because of its attribute of being a corrosion-resistant and durable material perfect for people who like to use their thermos in less-than-ideal environments like going camping or trekking. Glass or borosilicate glass can be used in thermos flasks. It protects the food items from the cold and warm by absorbing heat and holding it inside. It's easy to clean and does not require special treatment before use. 


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