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We have added long-term test instructions to Zojirushi stainless steel food cans.

Whether you pack peppers for lunch or oatmeal after commuting in the morning, an excellent food thermos can keep hot food at a safe temperature for several hours without leaking into your bag. After comparing 22 food thermos bottles and testing 10 of them, we are sure that Zojirushi stainless steel food cans are the best for most people. It has excellent heat retention, is durable and easy to clean, and is available in three sizes ranging from 12 to 25 ounces. We like the 10-ounce Thermos Funtainer food jar, which is used to pack lunches for children or those who prefer smaller portions.

This container can keep the food hot for several hours and is easy to disassemble and clean.

Why we like it: In our tests, Zojirushi stainless steel food jar is one of the products that can keep the soup hot. The 12-ounce thermos keeps the tomato soup above the food-safe temperature (140°F) for a full 6 hours, dropping from 193°F to 144°F. The only thermos flasks that do better are the 17-ounce Stanley Classic (larger volume of liquid takes longer to cool) and Black and Blum Food Flask (with a clumsy belt around it). Zojirushi said that its thermos can keep food at a safe temperature for about 6 hours. We are happy to see that for liquids, the thermos exceeds estimates (it can also keep food refrigerated for 6 hours, although we did not test this). I use Zojirushi stainless steel food cans several times a week to transport my morning green smoothie to work, and I also use it for chili, soup and oatmeal. It continued to maintain the temperature of the food and survived multiple commutes. Zojirushi's travel mugs have been our first choice for more than three years; the company produces the best thermos and thermos bottles we have found.

When shaken or turned upside down, Zojirushi did not leak (although none of the thermos bottles we tested leaked). The screw-in cap is easy to pick and place, and the narrow container can be easily held in one hand, unlike the wider and bulky Thermos stainless steel King or Stanley Classic. Zojirushi is also very durable and was unscathed in our drop test. Other metal cans dented when impacted, and the plastic caps on the IKEA thermos also shattered. In addition, Zojirushi's thermal performance has a five-year limited warranty.

Zojirushi has a detachable four-piece lid that allows you to deeply clean all crevices. We like it more than the one-piece caps on most other thermos bottles we have tested, they have hard-to-reach threads that look like they will trap sticky substances. After long-term testing of this thermos, I eventually lost a small rubber stopper inserted into the top of the lid. This did not affect the insulation, but sometimes food leaks into the lid of the thermos, so I give priority to unscrewing all parts of the lid to make sure I can get it clean. Although there was a slight leak due to the missing part, Zojirushi never leaked outside of the container itself. I have also seen it go through the dishwasher without clinking, even though Zojirushi recommends hand-washing hot water bottles. We also like that Zojirushi comes in a variety of sizes, including 11.8, 16.9 and 25 ounce jars, and a range of colors including pink, aqua blue, dark brown, cream and stainless steel.

Defects but not spoilers: We found that the cold milk in Zojirushi rose to 46 °F after only 2 hours (52 °F after 6 hours). The tuna rose to 49°F after 2 hours; after 6 hours, the temperature was 63°F. However, none of the thermos bottles we tested did better, even after pre-cooling with ice water (Zojirush recommends filling the thermos with cold water for one to two minutes before filling with food). Putting a thermos in a bag or lunch box with an ice pack can help keep the food cold, but in the end we found that these thermos are best for keeping warm (apologies to our readers who asked to use thermos to keep ice cream cold while hiking).

Although we like that Zojirushi's multi-part lid is easy to clean, it is a bit difficult to reassemble afterwards. Rubber gaskets are difficult to learn, and tracking the four small parts requires effort. In addition, unlike some larger thermos bottles, the lid of Zojirushi cannot double as a cup, so you may eat directly from the jar.

The regular pasta in Zojirushi also cools faster, dropping from 178°F to 82°F in 6 hours, but all the thermos we tested gave similar results. Solids like pasta cool faster than liquids, so any vacuum flask is most effective when used with soups, stews, oatmeal, or other liquid foods. In order to keep the food at a longer temperature, we recommend preheating the thermos.

We tested a can with a stainless steel surface, but have read several Amazon reviews and pointed out that the coating on the blue, pink and tan versions of the food can will scratch. We also found that the surface of the Zojirushi travel mug will show small scratches and wear over time, but this wear will not affect performance. We will continue to carry out long-term testing of the jar to see how it can withstand it.

The 10-ounce Funtainer is durable and easy to open with small hands. In addition, it has a variety of colors and prints.

*At the time of publication, the price was $13.

Why we like it: In our tests, the 10-ounce Thermos Funtainer keeps food hot, does not leak, does not break when dropped, and is easy to clean. Compared with the 12-ounce Zojirushi, we prefer children to use it because it has a series of interesting prints and colors, and we think the smaller size is easier for children to use. The cost of the thermos bottle is also lower if it is lost and needs to be replaced. Funtainer can fit neatly into smaller lunch boxes like our first choice, and can hold 10 ounces of noodles, vegetable peppers or hot cereals. Although the Funtainer can keep the food hot, it is not as effective as Zojirushi: After 4 hours, the soup in the Funtainer cools from 193 °F to 147 °F, and after 6 hours, the temperature is 130 °F. In contrast, Zojirushi kept the soup at a higher 144°F after 6 hours.

In our test, none of the thermos bottles, including the Funtainer, leaked. In the drop test, the Funtainer also outperformed its competitors. Its plastic lid did not break, while the lid of the child-friendly Contigo Food Jar cracked, exposing the Styrofoam under the plastic outer layer. The Funtainer's lid does not become slippery when wet, and it is easier to unscrew and unscrew than the convex triangular lid on the Contigo. Funtainer has a uniform cylindrical shape and can be easily fitted into all our lunch boxes. It also offers a variety of prints and colors to attract children of different ages (adults can choose the solid color option). Thermos provides a 30-day warranty for defective products.

Defects but not spoilers: All the thermos bottles we tested were unable to keep cold food at a food-safe temperature during the test, including the Funtainer. After 2 hours, the tuna salad that started at 40°F rose to 49°F; after 6 hours, the measured temperature was 63°F. If you are nervous about this, putting a thermos in a bag or a lunch box with an ice pack can help the food stay cold for longer.

The Funtainer has a detachable rubber ring to seal the thermos bottle, but since it is not completely separated, the lid has more back corners than the Zojirushi Food Jar, so it is a bit difficult to clean.

This container can keep the food hot for several hours and is easy to disassemble and clean.

The 10-ounce Funtainer is durable and easy to open with small hands. In addition, it has a variety of colors and prints.

*At the time of publication, the price was $13.

In this guide, we read six reviews and articles on thermos from publications such as Good Housekeeping and Popular Mechanics, and blogs such as A Well Pced Life and Mighty Nest. We also looked at the best-selling models in kitchen and home furnishing stores such as Amazon, IKEA, Target, Wal-Mart, Container Store, and Storables. Then, we carefully studied the products of well-known brands such as Thermos and Zojirushi. We considered models designed for children and general audiences. We prefer thermos bottles in a variety of sizes and colors, and tested smaller size options (from 10 to 13.5 ounces, and some 16 and 17 ounces) when possible, because we wanted an easy We select the best lunch box or bag for carrying and suitable thermos.

A good thermos should keep food at food-safe temperature for a long time-cold food below 40°F and hot food above 140°F. Thermos flasks are used to hold liquid foods such as soups or stews, and they should not leak. Because of an accident, they should not break or show obvious dents when dropped. Most companies recommend hand-washing thermos to maintain vacuum insulation, but the lid and jar should be easy to remove and clean.

In our tests, we considered how long thermos flasks can keep soup and regular bow tie pasta warm, how long they can keep milk and tuna salad cold, whether the thermos leaks, durability, and how difficult they are to clean. We heated the tomato soup to a boil, then added it to a thermos, and checked the temperature over 6 hours in 2 hour increments, and we did the same for the pasta. However, our pasta test is not conclusive-it takes longer to fill a thermos with wider bow noodles after tightening them than it takes to scoop out in piping hot soup, we think the pasta may be in Cooled down during this process.

We also tested each thermos with cold food, filling them with milk first, and then 4 ounces of tuna salad at 40 °F. Then, because the milk and tuna in all the thermos had risen above the food safe temperature after 2 hours, we repeated the tuna test after pre-cooling the thermos with 40 °F ice water (some brands, such as Thermos and Zojirushi, It is recommended to pre-cool the thermos, but we initially skipped this step because in real life, we would never take the time to do this). Even after pre-cooling the thermos, no one kept the tuna within the USDA's safe temperature guidelines after 2 hours.

After filling the thermos with soup, we shook them in our backpacks and then turned them upside down to check for leaks. We threw thermos bottles from a height of 4 feet onto the sidewalk to see if they were damaged after the fall. In order to understand the cleanliness of the models, we took them apart and washed them by hand. We also make sure that the thermos we tested fits the best lunch box we picked.

In order to keep the food at a longer temperature, Thermos and Zojirushi both recommend pouring a thermos into hot water to preheat it for 5 to 10 minutes, then pour it out and add the food. You can do the same with ice water, pre-cooling your thermos before adding cold food.

Like most thermos bottles we have seen, Zojirushi is not dishwasher safe and needs to be washed by hand. Putting it in the dishwasher will reduce its holding capacity. The Funtainer can be cleaned in a top dishwasher, but Thermos still recommends hand washing, because "stronger detergents and hot water may affect the appearance." To clean the hard-to-reach places on the Funtainer lid, we recommend soaking it in a warm Soapy water.

Although the Hydro Flask Food Flask's lifetime warranty left a deep impression on us, the thermos can only keep the food hot for three hours, and it will visibly dent when dropped.

In our tests, the Thermos stainless steel king 16-ounce food jar and folding spoon made the soup hotter than most competing products. But compared to our choice, it has a wider circumference and a larger ridge shape, making it more difficult to hold and put in a lunch box.

The smooth curves and brushed steel of Black and Blum Food Flask are very smooth, and the artificial leather strap and spoon attachment fascinate us. But this flask is not as widely available as our choice, and the device with a spoon does not work-the spoon will be exposed to the bacteria in the bag, and the strap can easily get dirty.

The 18-ounce Stanley Classic Thermos vacuum food jar can hold a lot of food and has a separate lid for consumption. But it does not offer a range of sizes as we chose, nor is it suitable for lunch boxes or tote bags.

We like the affordable MIRA Lunch Food Jar, but its insulation is not as good as most other thermos bottles we tested. The company also seems unable to maintain an inventory of MIRA jars in multiple colors, so we are worried about future availability.

Anna Perling is a full-time writer covering kitchen appliances at Wirecutter. During this time, she covered various topics, including sports bras, board games, and light bulbs. Previously, she wrote food and lifestyle articles for Saveur and Kinfolk magazines. Anna is a mentor of Girls Write Now and a member of the Online News Association.

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