Thermoses: specifications, types

— Thermos. Thermoses of a classic design: rather narrow and tall cylindrical vessels with a small diameter of the neck. They are intended mainly for a relatively pure liquid without impurities or with a minimum of impurities — tea, coffee, etc. Such vessels can be hermetically sealed, making them convenient for long hikes and trips. The average capacity of a classic thermos is from 500 to 1000 mL, but in general the range of such models is quite diverse.

— Thermos jug. A type of thermos designed mainly for home use and not intended for travel use. Distinctive features of such models are, firstly, rather large volumes (usually from a liter or more), and secondly, a spout for easy pouring of contents. Also note that it is among the jugs that the pump for liquid is most often found (see "Opening / serving"), in other types of thermoses such a device is practically not used. A thermos jug can be useful, for example, for storing a supply of hot water for tea parties during the day.

— Mug-thermos. Mugs with reinforced thermal insulation that allows you to keep the temperature of the drink for a long time. However, such vessels are designed primarily for ease of use “on the go”, and not for long-term storage of the contents (this is how thermo mugs differ from the thermos flasks described below). The design of thermo mugs often provides for valves or dri...nker lids (see "Opening / serving") that allow you to drink without opening the lid. Models with twist-on lids are somewhat less common — they retain heat more reliably when closed, but lose it faster when drinking. The capacity of all thermos mugs, of course, is small — usually up to half a liter.

— Thermos flask. Relatively small thermoses, shaped like "sports" bottles or camping flasks for water. The key difference between such models and conventional thermoses is that the contents of the flask can be drunk directly from the vessel without pouring it into a separate container (whereas it is difficult with a classic thermos, it is better to use a cup with it). At the same time, flasks are better suited for long-term storage of drinks than thermos mugs (see above), they can be used not only for drinking on the go, but also for transporting drinks on a long journey.

— Food thermos. Thermoses designed for hot food — soups, cereals, etc. A distinctive feature of such vessels is a wide neck through which not only liquid, but also rather large pieces of solid food can freely pass. In addition, the large neck width makes it easy to clean after use. And some models even come with containers for added convenience (see below). The volume of a food thermos can be up to several liters, although there are options for 400 – 500 mL.

— Children's thermos. Thermoses intended for children differ from "adult" models mainly in their reduced size and characteristic bright design. In terms of functionality, most of these models correspond to classic thermoses, however, there are other options — in particular, thermoses-flasks and food containers (for more details, see above).

— Automug. Specialized thermos mugs designed for use in a car. The key difference between such dishes and ordinary thermos mugs (see above) is the presence of a heating system powered by a car cigarette lighter. Auto mugs can be very useful on long journeys on roads where there are rarely cafes, gas stations and other places where you can get tea or coffee.

— The brew strainer allows you to prepare tea directly in a thermos. To do this, you just need to pour the tea leaves into the strainer and fill the thermos with boiling water. The tea strainer is a fine mesh, most often metal, that holds the tea leaves, preventing it from falling into the spill. Thanks to him, the purity and hygiene of the thermos, as well as the tea itself, increases. There are various options for the brew strainer. Often the sieve is simply built into the neck. In this case, the strainer acts as a coarse filter. Many thermoses have a strainer in the form of an elongated cylinder, with a deep immersion in boiling water. There are also other designs of the custard strainer.

— French press. A thermos with a French press allows you to brew natural ground coffee directly in a thermos. The French press itself is represented by a disc filter, which is pressed against the handle. When pressing on the handle, the disc filter presses the tea leaves to the bottom, thereby filtering out large coffee ground particles. The basis of the disc filter is a metal mesh. Under the grid it is recommended to put a special filter paper. Disposable paper filters are inexpensive. A French press performs two functions at once: pressing and filtering. The French press removes the bitterness of phenolic resin from coffee, which makes the coffee softer and more pleasant than ever.

The nominal volume of a thermos is the maximum amount of contents that it can be guaranteed to contain.

This parameter is directly related to the type (see above). So, a capacity of up to 500 mL is quite normal for a thermo mug, a flask or a baby thermos, but it is considered small for a classic thermos, and even more so a jug or a thermos for food. The "500 to 1000 mL" category includes most traditional and food models; for mugs, flasks and children's thermoses, this is actually the maximum volume. Among the jugs there are many more capacious options — from 1000 to 1500 mL. A volume of 1500 to 2000 mL is considered quite large, and the most solid models can hold more than 2 liters.

Anyway, a large volume allows you to hold more drink or food, but the downside of this is an increase in the size, weight and price of the thermos itself. Therefore, when choosing, you should not chase the maximum capacity, but proceed from real needs. For example, a model of 400 – 500 mL is quite enough for two cups of coffee, and for tea drinking at a halt for 3 – 4 people, it is advisable to have a model of at least 1000 mL. More detailed selection recommendations can be found in special sources; especially they will be useful to those who choose a thermos for long-distance hiking trips.

The type of main lid provided in the thermos. The main lid in this case is a device that directly closes the working volume of the vessel; an additional cap can be installed on top of it, which often also plays the role of a cup. In modern thermoses, there are such types of main lids: twisted (screw), valve, lid, hinged lid, drinker lid, pump (pump), cork. Here are the features of each.

— Twisted (screw). A solid (without holes) screw cap, secured with a thread. Such lids are very simple and at the same time reliable, however, you cannot drink or drain the contents through the classic twist — you have to remove it completely. There is also a more advanced design that allows you to drain the contents without removing the twist — just unscrew it partially; however, this is a rather specific variant, used infrequently. Anyway, twists are found mainly among classic and food thermoses (see "Type"), for which the mentioned nuances are not decisive.

— Valve. A lid (most often threaded) equipped with a valve through which the liquid contents of the thermos can freely pour out. Such lids are more complicated and more expensive than “deaf” twists (see above), however, to access the contents, you do not need to u...nscrew the twist every time, just open the valve. This not only provides additional convenience, but also reduces heat loss. Thanks to these advantages, valves are extremely popular in classic thermoses, and they are also often used in thermo mugs (see "Type"). The disadvantages of this option include the fact that the valve opening is usually made quite narrow and easily clogged with impurities (for example, tea leaves or coffee grounds). Therefore, the valve can only be used for liquids without such impurities (this also applies to food thermoses, which can also be equipped with valves).

— Lid. Covers in this case are devices that are not threaded (unlike the twists described above) and are held in place solely by friction or a latch. The design of the lids can be different: some cover the neck from the outside, while others are pressed inward when closed; there are also more specific options. Anyway, the lids can be easily removed and put back on, but they are not very reliable — for example, it is not recommended to turn such vessels over. Therefore, this option is found mainly in thermo mugs and thermoses for food (see "Type"), for which the mentioned disadvantages are not critical.

— Hinged lid. A variation of the covers described above, which, when opened, is not completely removed, but leans to the side on a special mount. This reduces the likelihood of loss: in fact, you can only lose the lid along with the thermos itself; and a latch, spring, or the like is usually provided to hold the lid in the open position. On the other hand, the mount somewhat affects the price and dimensions of the vessel. This disadvantage is the least critical for flasks and mugs (see "Type"), and it is among these types that hinged lids are most often found.

— Cover-drinker. Lid (plain or threaded), supplemented with a special hole for drinking. This design allows you to drink from the vessel without removing the lid; and in "non-working" hours, the hole is covered with a damper or other similar device. Drinker lids are extremely popular in insulated mugs and automugs (see "Type"): they allow you to comfortably drink from the mug while minimizing heat loss and spillage.

— Pump (pump). Lid (classic or threaded) with built-in pump. Most often, this pump is activated by a special button: when you press this button, a portion of liquid comes out of the spout, while the thermos does not need to be tilted. However, such devices are quite complex and cumbersome, so it makes sense to use them only in thermoses-jugs (see "Type"): the size and weight of the pump is small compared to the dimensions of the jug itself, and tilting such a thermos can be difficult — it is easier to use the pump.

— Cork. A classic cork that fits tightly into the neck of a thermos and is held in it without threads or other similar devices. The stoppers differ from the lids described above by their large thickness, and also by the fact that they are inserted into the neck from the inside (whereas the lid can cover the vessel from the outside). Plugs are very easy to use, but they have low reliability, which decreases even more as they wear out. As a result, this option has practically fallen into disuse.

The material from which the flask is made is the inner container of the thermos, which usually comes into direct contact with the product inside. Among the most popular modern materials are stainless steel, glass, plastic and ceramics; here are their main features:

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— Glass. The main advantage of glass over stainless steel is complete chemical inertness: such flasks do not oxidize and do not acquire an unpleasant odour over time. This makes them perfect for products where flavor matters a lot, such as herbal blends. In addition, this material retains heat better. On the other hand, the strength of glass is significantly lower, and such therm...oses are rather poorly suited for hiking — mostly glass flasks are placed in models that are not designed for difficult conditions.

— Plastic. This material is characterized by low cost and relatively low thermal conductivity (which helps to retain heat). On the other hand, the plastic surface does not tolerate prolonged contact with hot liquids: it can release unpleasant odours or even harmful substances. Thus, plastic flasks are relatively rare — mainly in thermos mugs, which, by definition, are not designed for long-term storage of hot drinks, as well as in inexpensive food thermoses.

— Ceramics. A material that is in many ways similar to glass: ceramics do not react with the contents of a thermos, do not affect its taste and smell, but are afraid of strong blows. At the same time, the reliability of this material is somewhat higher than that of glass — on the other hand, ceramics are more expensive. Therefore, this option has not received much distribution.

The material from which the body is made is the outer part of the thermos, inside of which the flask is placed.

— Plastic. One of the main advantages of this material is its low cost. In addition, it can be given any colour, and low thermal conductivity contributes to better temperature retention. On the other hand, plastic cases are noticeably inferior to steel cases in terms of strength and reliability, and scratches easily appear on their surface, due to which the product loses its presentation as it wears out. Therefore, plastic is used mainly in inexpensive models of thermoses.

— Stainless steel. Steel is somewhat more expensive than plastic, but much stronger and more reliable. In addition, the steel surface has a stylish appearance that is long-lasting thanks to its scratch resistance. Among the shortcomings of this material, in addition to the price, high thermal conductivity can be noted; manufacturers usually compensate for this moment with various tricks that further increase the price. Nevertheless, in general, steel is a very favorable material in terms of price and quality, and it is from it that the cases in most modern thermoses are made.

The main property of a thermos is to maintain the temperature of the liquid poured into it. Accordingly, the key parameter of efficiency is not so much the case material or some of its heat-insulating marketing chips, but the value of the water temperature after a certain period of time. So manufacturers, confident in the quality of their products, are happy to share their achievements. The temperature value after 6 hours shows how many degrees the boiling water poured into the thermos (98 °C) will cool down at an ambient temperature of about 20 °. And values of more than 80 ° can be considered very worthy.

The main property of a thermos is to maintain the temperature of the liquid poured into it. Accordingly, the key parameter of efficiency is not so much the case material or some of its heat-insulating marketing chips, but the value of the water temperature after a certain period of time. So manufacturers, confident in the quality of their products, are happy to share their achievements. The temperature value after 12 hours shows how many degrees the boiling water poured into the thermos will cool (98 °C) at an ambient temperature of about 20 °.

The main property of a thermos is to maintain the temperature of the liquid poured into it. Accordingly, the key parameter of efficiency is not so much the case material or some of its heat-insulating marketing chips, but the value of the water temperature after a certain period of time. So manufacturers, confident in the quality of their products, are happy to share their achievements. The temperature value after 24 hours shows how many degrees the boiling water poured into the thermos will cool (98 °C) at an ambient temperature of about 20 °. And with values of more than 50 °, a thermos can be considered one that keeps the temperature for a long time.

The temperature indicator shows the degree of cooling or heating of the contents of the thermos in real time. It can be represented by a display, a thermometer or other sensor to visually display the temperature. So, there are thermoses, in which the temperature indicator is a chameleon coating that changes colour depending on the temperature. Thermoses with an indicator are especially convenient for long trips, hikes and travels. Temperature control allows you to properly plan the time of eating / drinking and organize timely replacement of the contents of the thermos.

Own heating system built into the tank. This function is found mainly among car mugs (see "Type"), to use it, you need to connect such a container to the car's cigarette lighter. Note that heating is not a full-fledged boiler; however, in many models, it is able not only to maintain the temperature of a hot drink, but also to heat the liquid in a mug to fairly high temperatures.

The presence of a spoon in the scope of delivery of a thermos. This function is usually found in models designed for food storage (see "Type"); the purchase of such a kit will save you from having to look for a spoon separately. In addition, set spoons are sometimes multi-purpose camping cutlery (for example, a combination of a spoon and fork) and themselves can be more convenient than usual ones, often equipped with thermos mounts, etc. However, there are different opinions about the convenience of the entire thermos + spoon set. Therefore, if you are considering such an option, it makes sense to clarify the design features of the spoon, its attachment, etc. and, based on specific data, determine whether the kit will be more convenient than a regular thermos.

This feature means that the thermos is equipped with two cups or bowls at once (depending on the type, see above).

Many modern thermoses are equipped with a drinking cup or a food bowl; in the stowed position, such a container usually plays the role of a lid. In some models of cups / bowls, there can be two at once, which is useful if the thermos is used not only for yourself: you do not have to carry additional dishes with you separately.

The presence of containers for food in the design of the thermos.

This feature is found exclusively in food thermoses (see "Type"). Most often, such products have several food containers placed inside a common flask. This design is especially convenient in two cases: when you need to divide the contents into separate portions and when you need to load several different dishes into a thermos without mixing them. In addition, the size of the containers usually allows them to be used as deep bowls.

The number of containers can be different, depending on the size of the thermos; most often there are models for 2 – 3 containers. Also note that thermoses with this feature are usually not designed to be used without containers — in other words, it does not make sense to remove the containers and fill the contents directly into the flask.

The special handle for convenience of carrying of a thermos. The design of such a handle can be different: for example, in ordinary thermoses and thermo mugs (see "Type") it is usually installed on the side, in food thermoses and jugs — from above (and is made collapsible). The handle can be a structural element of both the thermos itself and its cover (see below). In addition, the small carrying strap that some models are equipped with is also considered a handle in this case (but the shoulder strap does not count, see below).

Anyway, holding a thermos by the handle is usually more convenient and safer than by the smooth body, especially when it comes to a large-capacity model.

The presence in the design of the thermos of a special belt, which allows you to comfortably carry the container on your shoulder. This function is usually found in large-capacity models, primarily food ones (see "Type"): it is much easier to carry a weighty thermos in this way than in your hands, and it's more convenient — your hands themselves remain free. Most often, the shoulder strap is attached to the thermos itself, however, in some models, it may be part of the complete cover (see below).

The thermos has a carabiner — a quick-release latch in the form of a loop with a spring lock. Thanks to it, you can easily fasten a thermos, for example, on a special loop of a backpack, or, during parking, on an awning stretch or even a tree branch. Carabiners are often found in "extreme" models, designed for long trips and difficult conditions, but they also come across in household thermoses. In some cases, this part may not be an element of the thermos itself, but a cover for it (see below).

The presence of a cover in the scope of delivery of a thermos. The cover performs two main functions: it protects the case from dirt and scratches, and also slightly improves thermal insulation. In addition, additional equipment — handles, straps, etc. — in some models is placed on the cover.

Note that the case can be bought separately or even made by yourself, but it is most convenient to purchase a thermos immediately equipped with a case.