Last Updated: 22-01-2020

10 Best Insulated Coffee Flasks 2021

Portable, reusable coffee cups are a brilliant idea to help you take your hot drinks on the go, but sometimes you need to take enough to fuel a few people, or so you have a supply throughout the day.

In this case, only an insulated thermal bottle or flask will do. You can fill it up, and the coffee will stay warm for hours so you can enjoy that hike or the full day at your desk.

Many will also accommodate cold drinks, so can be used for iced coffees and cold brews too (or for the rare occasion when you are taking a non-coffee drink with you).

These are our top picks of the best coffee flasks, thermoses and insulated bottles.

Our Top Picks

Image Product Details
Hydro Flask Water Bottle
  • Capacity: 0.35L, 0.47L, 0.6L
  • Size: Varies
  • Thermal Time: 6 hours
Check Price
Chilly’s Bottle
  • Capacity: 0.26L, 0.5L, 0.75L, 1.8L
  • Size: Varies
  • Thermal Time: 12 hours
Check Price
Stanley Unisex’s Legendary Classic Easy-Pour Growler
  • Capacity: 1.9L
  • Size: 16.4 x 12.4 x 29.3
  • Thermal Time: 18 hours
Check Price

The Best Thermal Coffee Flasks

Hydro Flask Water Bottle


  • Capacity: 0.35L, 0.47L, 0.6L
  • Size: Varies
  • Thermal Time: 6 hours

With a choice of colours from the dark and moody to the bright and vivid, as well as a pick of different sizes depending on when and where you are going, this bottle is the perfect companion for any eventuality.

The double-walled vacuum insulation will keep your hot drinks safe for up to six hours, which is likely plenty of time for any coffee addict to finish the lot off. It is made from 18/8 high-grade steel so is fabulous quality, and its also completely BPA free for anyone wanting to avoid plastic.

This also means that it won’t impart any funny tastes onto you drink no matter what you have in there. There is no absorption of odours either, and if you’re opting for a cold drink for the day, it will taste clean even 24 hours later.

With a powder matte finish, it will never look covered in condensation and will be hard to tarnish too. This also means you won’t have moisture dripping down your work shirt or leaving a puddle on your desk.

Reasons to Buy

  • Choice of colours
  • Choice of sizes
  • High-grade stainless steel

Reasons to Avoid

  • Larger sizes do get pricy

Chilly’s Bottle


  • Capacity: 0.26L, 0.5L, 0.75L, 1.8L
  • Size: Varies
  • Thermal Time: 12 hours

A travel cup just isn’t appropriate for your commute. You always end up with coffee over your bag, it isn’t as warm as you like when you reach the office, and it simply doesn’t hold enough either.

Chilly’s bottles are perhaps the most famous insulating bottles around. Mostly used for cold drinks by those who want something reusable, they can actually also keep your hot drinks hot for up to 12 hours.

The food-safe stainless steel will never rust or impart any odd tastes onto your drink, so it still tastes fresh hours after first making it. With a leak-proof screw top lid, it is easy to drink from and also easy to pour from so you can serve yourself all day, or the family when out on a hike. This is narrow so you won’t risk missing your mouth.

Two-ply construction means there is no condensation on the outer, so you won’t get dripping water or slippy cold hands. It’s lightweight and fits in most cup holders, making it an ideal travel bottle.

It is also the top pick if you are looking for the best small hot drink flask.

Reasons to Buy

  • Lightweight
  • Massive selection of colours and patterns

Reasons to Avoid

  • Larger size can be hard to hold

Thermos Stainless King Flask


  • Capacity: 1.2L
  • Size: 3.7 x 4.3 x 12.3 cm
  • Thermal Time: 24 hours

Thermos is a generic term which many people use to describe a thermal flask, a bit like when people refer to vacuum cleaners as Hoovers. So as you’d imagine, the brand is pretty good at what they do.

If you’re off on a road trip and overnight camping stayover, this generous capacity flask will keep your coffee warm for an entire 24 hours. This is two or three times as long as most of its closest rivals, which is very good going indeed. It makes it the best thermal coffee flask in terms of the time it can keep hot drinks hot.

The durable stainless steel will largely stay free from dents and scratches, and you also get a little serving cup on the top which is perfect for when the pit stop break arrives. With a twist and pour stopper, you don’t need to remove any lids to get the coffee flowing, and it stays leak-proof as well.

There’s a handle which makes it easier to pour from, and even though this isn’t fixed so it saves space and therefore rattles a little when carrying, it is still really safe and sturdy to hold which eliminated the risk of accidents.

Reasons to Buy

  • Large size
  • 50-year guarantee
  • Good value

Reasons to Avoid

  • Pouring stopper gets quite hot

Stanley Unisex’s Legendary Classic Easy-Pour Growler


  • Capacity: 1.9L
  • Size: 16.4 x 12.4 x 29.3
  • Thermal Time: 18 hours

Almost two litres of coffee can be held in this thermal flask, which is pretty astounding and will keep an entire group of caffeine lovers happy for the full day it stays warm.

It is primarily a growler, used to transport beer from breweries, but is just as effective at keeping coffee hot as it is keeping beer cold and crisp. And we would imagine that there is more demand for a huge coffee flask than for a beer transporter out there.

Environmentally safe and natural, it can be used over and over again and there is never a metallic or plastic taste in your drinks. A nice grip handle will allow you to serve it all out, and the clip lid is sturdy and easy to fasten and undo for one-handed pouring.

More of an iced coffee fan? It can keep drinks cool for 24 hours and iced drinks icy for up to four days. Pretty phenomenal.

Reasons to Buy

  • Huge size
  • Keeps drinks maintained for a long time

Reasons to Avoid

  • Have to be careful with lid as it can leak slightly

T2 Tea Insulated Flask


  • Capacity: 0.5L
  • Size: 7.1 x 7.1 x 22.9 cm
  • Thermal Time: 6 hours

You don’t want tea, you want coffee. We hear you. But it doesn’t mean we can’t use some of their products, because after all, we all do come together in the search for a hot drink.

The idea is that you pop loose tea leaves into the diffuser and the taste stays strong over time. This could be good for anyone who wants their coffee granules to develop in order to make a flask of cold brew, or you can leave it out altogether if your drink is already perfect.

Screw the top on and then place it into your bag for coffee on-the-go. It won’t leak everywhere, so running for the train is no longer a difficult process. It can keep drinks warm at 60°C for up to six hours which will get you (almost) through a working day.

It would make a great flask for anyone who sometimes loves tea, sometimes needs a coffee, occasionally tries a green tea when on a health kick and sometimes adapts their hot drinks for the summer months.

Reasons to Buy

  • Leakproof
  • Can be used for any hot drink

Reasons to Avoid

  • Can be hard to grip and pour if you have small hands

SIGG Switzerland Unisex’s Hot and Cold Insulated Water Bottle


  • Capacity: 0.75L
  • Size: 8.2 x 8.2 x 29 cm
  • Thermal Time: 18 hours

When you are travelling, how long a bottle will keep your drink warm for is really important. But as is how you drink the coffee and how the bottle can be carried. All of that makes this one the best flask for travelling.

This one is slim and convenient, with a practical screw cap which also doubles up as a carry handle. It can be hooked onto a bag, a waist belt, around your neck or simply carried by hand (although it is on the heavier side so maybe best in a bag for long periods). The integrated mug is handy as it takes up no more space, yet is always there when you need it.

Able to keep hot drinks for 18 hours and cold for 24, it will see you through the day no matter the contents. It is made from stainless steel and avoids BPA, pollutants and phthalates.

Reasons to Buy

  • Comes with a cup
  • Handle to carry

Reasons to Avoid

  • A little heavy

Tefal Senator Vacuum Flask


  • Capacity: 0.35L, 0.5L, 0.7L, 1L
  • Size: Varies
  • Thermal Time: 12 hours

Tefal is a big name in the general kitchenware world, continuously making products which revolutionise lives.

They’re perhaps best known for their pans and air fryers as opposed to their vacuum flasks but as you would expect, a brand with so much knowledge has made a very good product here.

The safe lock lever ensures no leaking and that it pours precisely, and the lid on the top can also double up as a small cup. It is virtually unbreakable, so even the most active of adventurers will struggle to make a dent on the outer layers.

You can buy it with a stainless steel finish or with a black or red silicone wrap, which would be best for anyone who will be carrying it for a while.

Reasons to Buy

  • Very sturdy
  • Easy to hold

Reasons to Avoid

  • Underwhelming design

Klean Kanteen Classic Stainless Steel Water Bottle


  • Capacity: 0.35L, 0.6L, 0.95L, 1.8L
  • Size: Varies
  • Thermal Time: 20 hours

A really popular brand and bottle across the pond, Klean Kanteen is also a best seller in the UK and the glowing reviews are perfectly understandable.

The large 44mm bottleneck opening is large enough to fit in ice if you are opting for a cold drink instead, and will also make it easier to fill the flask with water and pour from it. It can keep a drink hot for 20 hours, making it one of the best picks for heat duration if this is your main concern.

We love how you can buy other caps and lids for the bottle, from a sippy cup or a classic water top to a wider loop cap or cafe cap which you can pour from. It comes with the traditional leak-proof ring cap, which is perfectly fine for general use.

There are also matching reusable straws, cups and tumblers to buy, and they sell a brush which can help you to get it sparkling clean inside again.

Reasons to Buy

  • Long heat time
  • Large opening

Reasons to Avoid

  • Could be easy to dent or mark

Bodum Bistro Thermo Jug


  • Capacity: 1L
  • Size: 12.1 x 18.1 x 24.1 cm
  • Thermal Time: Six hours

A Bodum product makes it on to pretty much every coffee accessories list we do. And it is no surprise, given their popularity and quality.

This Chambord is a jug, so best for anyone who will be taking a large serving of coffee on a picnic, to a work meeting or in the car for a drive. It pours without dripping and most importantly keeps the hot drinks warm for hours.

The plastic outer doesn’t get too hot to touch, which is great for when multiple people will be using it. Available in black, off-white and bright green, the jug has managed to retain the classic Bodum handle styling which makes their other products so famous, which is a nice touch.

Reasons to Buy

  • Nice style
  • Easy to pour from

Reasons to Avoid

  • Can suffer from a bit of condensation when the drink is really hot

Brushed Steel Insulated Vacuum Flask


  • Capacity: 1L
  • Size: 31 x 8.5 x 8.5cm
  • Thermal Time: 4 hours

Personalised coffee products make really nice gifts. The ability to add custom text to this plain yet great quality flask will appeal to anyone who knows somebody who is always complaining about the cost of coffee at their work/in Starbucks and needs it to stay warm.

Or maybe, you need to put your own name on a flask because Jennie from the office is always pouring from your flask ‘accidentally’. Or because your other half is always getting your coffee flask mixed up with their fruit tea one and then complains that your coffee has stained slightly.

It looks deceptive as it can actually hold one litre of drink. The screw-on lid doubles as a cup, while ensuring no spills escape into your bag.

The engraving will last a lot longer over time compared to a print, especially when it is washed and carried all day. For the price, you get a very good product indeed, and it is the best personalised flask we found.

Reasons to Buy

  • Can be engraved
  • Holds a surprising amount

Reasons to Avoid

  • Engraving may not be clear enough for some people

Hot Drink Flask Buying Guide

Thermal Time

When you are looking for a flask which can keep your hot drinks in perfect condition, you will probably be concerned with how long they can do this for.

Some people will need to keep theirs warm for just a few hours, whereas others may need something which will work overnight on a camping trip. The thermal time can range anywhere from around four hours up until 24 hours.

It is worth bearing in mind that how hot the drink is in the first place could affect this time, as could how long the lid is left off. The addition of cold milk can also bring the temperature down a few degrees.

Many thermal flasks can also keep cold drinks cool. This will usually be for a lot longer than they can keep hot drinks warm, which is understandable but can also be worth looking at if you will be making your flask multi-use.

If you are a full hot coffee aficionado, you may even want to keep the milk in a separate cold bottle.


This can range from around 300ml to almost two litres for these flasks. Which size you will need will depend on how many servings you will be making.

A cup can usually hold between 220ml and 340ml of liquid. Check how big your travel cups are if you’re using some, and work out how many cups you will need out of the flask.


This is a guide on the overall dimensions of the flask. You may be restricted over where the bottle can fit, such as in a bag, or simply don’t want to carry a huge flask around all day.

Pour Spout

There are various options here. You can remove the entire lid and pour from the jug or bottle as normal which is good if you will be pouring into a mug. You can press down on openings to have a more restricted flow which may be better for controlled pouring or drinking straight from the flask.

Remember that larger spouts could be easier to get the water and coffee into the flask, but can be less controlled to get it back out again, so it is all about finding the balance which is right for you.


This is down to personal preference. You can opt for the traditional screw-top stainless steel bottle or something a bit more bulky with handles, extra cups and which is easier to carry. Many offer a choice of colours or designs.

How We Have Picked Our Best Thermal Flasks

First of all, we looked for a capacity of at least 500ml. This gives you two cups of coffee on average, or enough to sip at for a few hours until it starts to do cold. There are a few on our list which holds less than this, but depending on your circumstances this may be all you need.

We looked at the time for which the hot drinks can stay warm, aiming for a range between six and 24 hours so everyone is happy. We also wanted products which are easy to carry and transport, hold when pouring, and which won’t leak in your bag nor pick up condensation.


Are Coffee Flasks Easy To Clean?

Usually, no. Which is a given with their design really. This makes it important for you to know how to clean them before their first use.

You can’t stick your hand in them and it would be difficult to get a washing-up sponge inside, but you have to try and clean them ASAP so the coffee doesn’t stain and the taste doesn’t stick around.

You can now buy bottle brushes which will get right into the bottleneck and down to the bottom. If cleaning is not something which you are keen on, you may wish to opt for a larger flask with a wide neck which is easier to get into.

You can get the smell out of a bottle by using some vinegar and hot water and allowing it to steep before air drying. Bleach should never be used, and flasks should always be dried fully after use to stop the growth of mould.

Do I Need A Handle?

Many of the larger flasks come with handles. This makes it easier for you to pour from them, especially if you have smaller hands. It isn’t necessary, and indeed a handle could take up valuable carrying space, but do remember you will be working with hot drinks so safety is key.

What Is The Optimum Temperature For Flask Coffee?

Around 80°C is said to be best for serving coffee, but some experts say that something more around 40°C to 50°C is optimum to ensure the coffee does not burn and the taste isn’t damaged.

For this reason, the majority of flasks will be able to hold your hot drinks at around 60°C. You also don’t want it being too hot in case you have a spillage when pouring, or it leaks.


Share on facebook
Share on google
Share on twitter
Share on linkedin
Share on pinterest
Share on print
Share on email
Scroll to Top