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.
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.