The thermos test: who can keep me warm the best??

Summer dreams of coolness and fresh air came true, and we happily plunged into winter pleasures: skiing, skating, ice sledding – all in the good company of friends, kids and loved ones.

You may get warm anyway, just from positive emotions, but it is more likely that after an hour or two you will want to warm up, of course, with hot tea from a thermos.

And so that you can drink really hot and delicious tea all winter long, we… have been testing thermoses all fall.

Consultants: Alesya IVLEVA, “Technologies of cold 2000”, Margarita NECHIPORUK, JSC “Ashinskiy metallurgical works”, Fedor ZAKHAROV, “Arctic”, Davlat SULEIMANOV, Regent INOX, Maria SEMENIKHINA, Vitesse.

Six Brave

We conceived the test of thermoses in anticipation of winter and wanted to cover as many models as possible, but from very many brands we will not say that the manufacturers, rather their dealers-sellers received a polite refusal to provide models for testing. That’s why you won’t see here some of the widely available thermoses, both domestic and imported. We hope that the uncovered comrades will have the courage for the next test. In the meantime, let’s introduce the participants:

1. ARCTIC 205-1000

2. THERMOS FBB-1000 VS-Midnight Blue

3. THERMOS 2590 Floating

4. VITESSE Lusile VS-1400

5. AMET “TURIST” type “K”, 1c55

6. REGENT INOX 93-TE-U-1-1000

What we tested

Iron! – material and its properties

The most reliable, from the experts’ point of view, are thermos flasks, the body and the bulb of which are made of stainless steel they often use vacuum technology as well . These appliances were tested for a number of reasons.

For a very long time thermoses with flasks made of stainless steel were considered, firstly, heavy, and secondly, not as hygienic as those with glass flasks. But in the last decade, modern technology has allowed most major manufacturers to eliminate these shortcomings.

It was interesting to find out which of the manufacturers really succeeded, and which use grandfather’s methods. That’s why all of our thermoses and we have them of the same volume, which will be discussed below , we weighed and tested for hygiene and safety.

If with the first there were no difficulties, with the second everything is much more complicated. Only a laboratory can give a conclusion about these parameters, but we only test for a few attributes and share our observations. So, we tested:

INFORMATIVENESS. This is what the manufacturer is obliged to provide the consumer, this is what will warn the buyer against improper use of the thermos, which, oddly enough, can be a potentially dangerous object.

It is important that there is information about care, storage, use for certain products and that the flask is labelled with the material used for the flask on the appliance or the packaging. For the flask that comes into contact with food only stainless steel of high quality should be used – so-called food or medical stainless steel.

MATERIALS. It concerns first of all the chrome-nickel alloys marked “18-8” or “18-10”, which are the guarantee of the high degree of corrosion resistance and, therefore, safety for the health of consumers.

We also paid attention to the presence of a voluntary certification mark “RosTest. Going through this procedure is also a demonstration of respect for the consumer and a guarantee of confidence in the quality of the goods.

Inertness neutrality of the material of the bulb in contact with hot food. This is a sign of both safety and hygiene at the same time.

Material flask should not be loose, easy to wash, does not allow any chemical reactions with the products, in fact, in addition to unpleasant taste sensations eg, tea with a taste of chicken broth and bad washable walls, this thermos can “reward” the user allergic reactions, poisoning, and with systematic use – the accumulation of harmful substances in the body.

How we tested it

We have chosen the most consumer way of testing: with organoleptic indicators of safety and hygiene. We put each flask to the test:

– inner surface smoothness absence or presence of burrs, roughness, dents and other defects . Only visual inspection and tactile sensation could help us, so we used a flashlight and examined the lit “insides” of each thermos as much as possible, and then, deciding that the most sensitive tool was our own fingers, we conducted a smoothness test by tactually examining the inside of the flask about 9-10 cm deep

– the ability of the flask to get rid of all the flavors and smells of beverages poured into it earlier, indicating the inertness of the material. To do this, we studied the care instructions for each appliance if any and followed them when washing the thermos, and then had a multi-day tasting of drinks from all the thermos.

We tested each thermos separately from the others, so that the approbants are not confused and can be more objective. We kept the beverage in the thermos for at least 16 hours, simulating the situation when the thermos washed of the remains of the poured beverage only the next day we hope you do not doubt that after each drink the thermos took water procedures, and then also dried without a lid .

So, the first test – the usual black tea from a thermos. Since we never poured anything in a thermos before, the tasters were just asked to evaluate the taste of the drink for its extraneous odors and flavors.

The second test was an herbal tea with chamomile, lemon balm, mint and honey very fragrant ! . That is what we expected to “flavor” and stain the flask properly, so we brewed herbs directly in the thermos.

The third stage – coffee. We didn’t want to use an instant drink, we wanted something more aromatic and we chose a finely ground natural dark roasted coffee oriental style .

The fourth and final stage – no, not mulled wine although it would be nice! – normal boiling water, which in theory should not smell bad, given the hygiene of the flask.

Neither two nor one and a half – the volume

We opted for 1 liter thermoses. We proceeded from the fact that in winter we want to take tea with us directly to the rink, on the slide, in the park, and, of course we remember you, fans of winter fishing ! , on a river or lake.

One liter of tea is enough for 4 cups of 250 ml or 5 cups of 200 ml – quite enough for a standard family of two or four people or a small company for a small tea party, it is not heavy to carry, convenient to place in the bag.

It was getting lukewarm? – Ergonomics and… safety again

Where the thermos – there is boiling water, so it is very important to eliminate the risk of burns when you open the lid and check its tightness. We looked at the lid designs and the features they provide, and we checked to see if the thermos opens when you flip it over or shake it vigorously. Let’s say right away that none of the participants leaked when the cork was properly and tightly screwed on. It’s a good thing.

Trivia of Life – Usability

Neck, cap, handle, lid – all thermoses have different size and construction, and it is these features that make up the full quality picture of the thermos. It can keep warm just fine, but you’ll be tortured by the cork, or it can be beautiful, but easily overturned..

We’ll tell it like it is and you’ll think about which design flaw can be tolerated and which can’t. And one more important point: the most vulnerable place of any thermos is the neck. It is through it that such valuable degrees gradually go away.

Consequently, if you compare the temperature readings of a thermos with a narrow neck and a thermos with a wide neck of the same class and quality, the first “by default” will give higher temperature readings than the second.

It is thrown from the fiery crucible into the freezing cold… – the ability to retain heat

And “in this repeated torture” we had the answer to the question posed in the title. To check the ability of each thermos to retain heat two experiments were conducted with each of them: storing the thermos in a refrigerator +4 ° C for 24 and 12 hours.

For each test, we poured boiling water into the thermos immediately after boiling the kettle at least +99 °C , closed the lid, and held at a given temperature. We preheated each thermos with boiling water: poured it up to the neck, sealed the cap, and kept it on ice for 5 minutes – this is what almost all instructions recommend, and we took it as a general rule for the test. All the results are in our summary table.

It is interesting to compare them with the temperature specifications listed in the instructions and on the websites of manufacturers although all the standards are given for testing at room temperature, but we did the test is much stricter .

By the way, the official representative office of THERMOS in America told us that the manufacturer’s specifications on keeping the heat in the watch should be oriented to the threshold of 70 °C in European standard and 50 °C in American standard.

Thus, the temperature of the hot beverage can not be less than 50 ° C after the manufacturer’s stated time interval 12 hours . There is no officially accepted standardized concept of “hot” temperature in America yet.

What we didn’t check?

– We consciously did not test the ability of flasks to retain heat at room temperature. Unlike refrigerator and freezer temperatures with electronic thermostats, the temperature in the test room is naturally not the same every day.

But the instructions for the thermos, as a rule, contained the declared norms of temperature, which should show the thermos during the tests exactly at room temperature we also put this information into the table – for clarity .

– After conducting experiments in a refrigerator we decided to abandon the idea of putting the thermoses also in the freezers: the results of the first tests showed the quality of the devices, and the standards specified by the manufacturers, should be measured at room temperature.

– It is not possible to fully test the effectiveness of vacuum technology outside of a laboratory setting. We were only able to judge its effectiveness in preserving heat.

– We have not tested the ability to keep warm even though all thermoses are designed for this purpose: Firstly, it is irrelevant in winter, and secondly, if the device keeps warm well, it means that the cold will be kept for two or three times longer.

– We have not crash-tested or attempted to mechanically damage the thermoses or negatively affect their ability to retain heat. There is an opinion that this quality suffers when the casing especially of vacuum thermoses is dented or mechanically damaged, but the experts of the leading companies assure us that in this case it does not suffer, but loses it completely.

Handle with care, no matter how unlikely the damage to the stainless steel can be.

Conclusions

1. All participants meet or exceed the heat preservation parameters declared by the manufacturers. The best thermoses that passed the test were those using vacuum heat preservation technology.

2. We had no complaints about hygiene and safety – as long as the instructions and safety precautions were followed, everything would be fine.

3. In terms of ergonomics, the differences are quite noticeable: even the two seemingly identical models – “Arktika” and REGENT INOX – are slightly different in terms of convenience.

The shape and size determines whether you can take the thermos with you and in which bag the stability determines whether it can be used for traveling e.g. on a train or if it can be used on an uneven surface e.g. camping .

One of the most important indicators of convenience is the pliability of the cork: no one wants to break their nails and call for help if they can’t open a tight or uncomfortable cork.

Did you know that?

Designation “18-10” historically comes from the times when the trendsetters on stainless cookware market were German and Italian manufacturers who manufactured cookware of German steel X5CrNi18-10 according to the German DIN standard , which was abbreviated as “steel 18-10”.

But now it is accepted to put such marks on the products made not only from German steel, but also from steel of Finnish, Swedish, Brazilian and other manufacturers according to ASTM standard and domestic steel 08X18H9-10. These materials are chemically similar to “18-10” and differ only in the marking indicating the manufacturer of the material, since each country may have its own standards.

According to American normative and technical documentation, goods made of corrosion-resistant steel, similar to “18-10”, produced in America, are marked with a material marking “stainless steel”.”No other usa GOSTs.

Test results of thermoses with bottom diameter 110-120 mm

Model name	Weight, g	Volume lids, ml	Company info (at 20 ˚C	Water temperature after 24 h cold. camera	˚t of water after 12 h cold. chamber	ergonomics (of 10 points
ARCTIC 205-1000	670	340/200	6h – up to 70-80 ° C, 12 h to 60-70 ºC	42 ° C d = 120 mm	63°C	7
AMET “TOURIST” type “K”	1139	380	24 h – to 49 ° C	48°C d = 110 mm	63°C	5

Test results of thermoses with bottom diameter of 80 mm

Model Name	Weight, g	Volume lids, ml	Company data (at 20 ˚C	˚t of water after 24 h in a cold. chamber	˚t of water in 12 h in cold. chamber	ergonomics (of 10 points
THERMOS FBB-1000 VS-Midnight Blue	530	160	12 hrs over 50 ºC	58°C d = 80 mm	67°C	9
THERMOS 2590 Floating	775	160	12 hr – more than 50 ºC	58°C d = 80 mm	68°C	8
VITESSE Lusile VS-1400	670	280	12 h – 76 °C, 24 h – to 64 °C	44°C d = 80 mm	64°C	9
REGENT INOX UNIVERSAL 93-TEU-1-1000	655	300/200	24 hours to 40-48 ºC	52°C d = 80 mm	61°C	8