We dropped each flask five times from 90cm to mimic a dropped flask. Those with large dents that inhibited function or ability were rated low. Also called catering flasks or thermos pump pots, airpots are well-insulated, as well as being easy to transport, and are very simple to use for all your members of staff. They can be used for a variety of purposes, including, but not limited to; buffets, cafes, restaurants, events, parties, meetings and even outdoor events. This is because airpots are able to keep either coffee, tea, or other types of hot beverage at a high temperature, for a number of hours. Airpots are also a simple alternative to making your hot drinks fresh every time. Airpots are very portable and can be used on any sort of flat surface. This means that they cannot only be used by your members of staff behind a counter or other type of service space, but they can also be used by customers at a self-service area, provided they are supervised by staff of course. They can also be used at various parties, meetings or events, depending on what your individual business provides. Insulated cup: Good flasks also pay attention to the insulation of the detachable cup, if they have one. This is so your drink stays warm while you’re drinking it. Meanwhile, the outside stays cool, so you don’t risk burnt hands.

Without cleaning your airpot properly, the left-over residue from previous heated hot drinks can contaminate your new pot of hot drink. This is not only a health and safety issue which can potentially harm your customers, resulting in food poisoning or other stomach complaints, but it can also taint the flavour of your fresh pot of hot drinks too. Therefore, cleaning your airpot frequently is a necessary requirement for all businesses.

Our pick of the best Thermos and vacuum flasks will keep your brew hot and your lunch cool all day

Leave this vinegar and hot water solution to sit inside the airpot overnight - approximately 10-12 hours, or less, depending on how dirty your airpot is. Stainless-steel also provides a corrosion resistant layer, which means it will not change the flavour of the hot drink contained in the airpot, no matter how many hours it sits there. Additionally, it is also a long-lasting material, that cannot be easily scratched, scuffed or marked. So, even when faced with the most vigorous of pot washing or handling, which will occur on a day-today basis in busbusy environments, it will not be damaged. Rinse your airpot with hot water, which is usually dispensed from an attachment above, or other hot water source. Make sure that most of the dirt and grit is removed by swilling the water around and removing the bits which you can deal with manually. This should be repeated as many times as necessary, depending on how dirty the airpot is. A Thermos King will last years but it’s not officially dishwasher-safe, and you’re not even meant to submerge it in water (if you do, you kill the manufacturer’s 50-year guarantee). Inquisitive users report that it does survive the dishwasher intact, albeit with peeling colour.

Add whichever dish detergent your business usually uses and, again, swill this around the airpot. Much like the step above, repeat this as many times as necessary to initially clean the airpot so that it looks clean. Below is an easily followed step-by-step guide on how to clean your airpots, no matter how small – or large - they might be: Flasks are more 'smell prone' than 'stain prone' – none of the flasks we tested had any staining after cleaning, but some retained a faint coffee smell. We examined each flask and its pouring mechanism and attachments for faults. We penalised flasks that had faults affecting their usability.

The best flasks to buy in 2023

Run the hot water through the spout - if it is a lever airpot - to make sure that the grits and any other residue is thoroughly rinsed out. When it has been sat for the appropriate time, rinse out your airpot with hot water once more and clean out any residue which might be left over from any previous hot drinks held inside.

Multi-wall insulation: Double-wall insulation creates a vacuumed layer, which is vital for keeping hot drinks hot and cold drinks cold. Some flasks include more layers for even better insulation. The 100% stainless steel construction of today’s flasks means there’s no risk of inner walls shattering when dropped.As a result of the small, and often very intricate areas in airpots, they can unfortunately be troublesome to clean. Unlike espresso machines, and other forms of hot drinks dispensers, airpots can be quite difficult to clean by hand. Therefore, they have a tendency to retain some of the coffee grits, or other contaminating materials from other hot drinks in the crevices of the inside pot. However, glass lined airpots are much more likely to break than their stainless-steel counterparts, simply because glass is a much more fragile material. This means that, although they are cheaper than stainless-steel and better at insulating too, glass-lined airpots may have to be replaced more frequently than stainless-steel models, and may therefore be more expensive in the long-term.