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When you're always on the go, it's easy to get into the habit of stopping for a quick-service meal, but relying on fast food can also add up—both calorie- and money-wise. With the right storage containers, taking homemade food along to the office, school, or on a road trip is a cinch.
The Thermos Stainless King Food Jar was the clear-cut winner after extensive testing. This thermos kept foods hot for a spectacular nine hours and cold for an astounding 14 hours. For a cheaper option, consider the Mira Vacuum Insulated Stainless Steel Lunch Thermos, which comes in multiple colors and is easy to clean.
To help find one that suits your needs, we researched top products suitable for packing up leftovers or make-ahead meals, as well as dishes to add to the kids' lunchboxes. We tested to see how long our best models would keep hot food warm and cold drinks chilled.
Here are the best hot (and cold) food thermoses for the whole family.
Best Overall: Thermos Stainless King 16-Ounce Food Jar with Spoon
Retains heat well
Firm seal prevents leaks
Includes full-size spoon
Plastic laminate gradually peels off
Thanks to an uber-tight seal, the Thermos King is touted as having maximum temperature retention for hot and cold food. That's thanks to the insulation from two walls of stainless steel. Another significant benefit is that the lid is designed to be used as a bowl in tandem with the included standard-sized stainless steel folding spoon.
Thermos states this can keep liquids hot for nine hours and cold for up to 14 hours, so we put that claim to the test in a home kitchen. Our reviewer filled all 16 ounces with freshly made mac and cheese and opened the thermos every hour to see if the temperature remained consistent. It wasn't until the ninth hour that the temperature dipped. Additionally, it excelled at keeping water ice-cold, with our tester still observing ice cubes after 14 hours in the thermos.
Our home tester intentionally dropped the thermos and noted that it wasn't damaged in any way. Also, its wide mouth is useful for eating straight from the container, and when you need to quickly hand-wash it. Each component of this model can safely be washed in the top rack of your dishwasher, allowing easy upkeep for busy professionals on the go.
Capacity: 16 ounces | Heat Retention: Up to 9 hours | Cold Retention: Up to 14 hours
"After our test, we were confident that the container would work well for soups and other foods that are even hotter to begin with." — Suzie Dundas, Product Tester
Best for Kids: Thermos Foogo Vacuum Insulated Stainless Steel Food Jar
Easy-to-grip rubber lid
Wide mouth is easy to eat from
Lid seal needs occasional deep cleaning
Ergonomically designed with kids in mind, the BPA-free Foogo is a favorite with parents, as its cool-to-the-touch 10-ounce body is the perfect size for a kid's lunch. The base and lid are made of rubber to make the jar easier to grip for smaller hands, too. Other perks include cost efficiency and a tough body resistant to scratches.
Our home tester liked the double-wall insulation and its compact size since adults can also use this for hot sides and drinks. But our reviewer focused on one of the most important aspects of a thermos: how long will it keep your food hot? Thermos claims that this keeps food warm for up to 5 hours, and it fell short in our tests. Mac-and-cheese only stayed hot for 2 hours, was still warm enough to eat at 4 hours, and needed to be microwaved (in a separate container) by 5 hours. When it came to cold liquids, it did live up to its 9-hour claim, with ice cubes still present after a full workday.
When it came time to clean up, our tester noted that though this is dishwasher safe, you might be better washing it by hand. There was food caught in the lid, gasket, and the container necessitating a scrub down with a sponge.
Capacity: 10 ounces | Heat Retention: Up to 5 hours | Cold Retention: Up to 7 hours
On hot days, Kate Bast, nature and forest therapy guide and founder of Shinrin-Yoku Madison, recommends hikers bring at least twice as much water as they think they need, even if that means bringing two or more thermoses. She also suggests adding hydration packets to water or filling a thermos with fruits that have high water content, such as watermelon, which can be frozen the night before to maximize coolness. On chilly days, Bast carries one thermos with room temperature water and another containing a hot or warm beverage.
Runner-Up, Best for Kids: Thermos 10-Ounce Funtainer Food Jar
Available in a variety of colors and themes
Wide mouth is easy to eat from
Hand wash only
Too small for older kids and adults
Kids will adore the array of colors and character themes the Funtainer comes in. More importantly, a wide brim makes eating less challenging for little ones getting the hang of using utensils, and the stay-cool exterior won't harm their hands. Best of all, it's lightweight and compact enough for little hands to open and carry in their backpacks.
It's imperative to strictly adhere to the instructions for use, such as warming the interior with hot water for five to ten minutes before adding any food that will be eaten later. Our home tester found that when you did, this kept hot food warm for 5 hours, even if it was opened every hour to test the temperature. It also kept cold beverages cool for 7 hours, with ice cubes still visible at the end of the test.
Cleaning this in a home kitchen was a little tricky for our tester. It can be put in a dishwasher, though the hot water and detergent might damage the exterior. Washing the interior of the lid does require a sponge and some detailing by hand.
Capacity: 10 ounces | Heat Retention: Up to 5 hours | Cold Retention: Up to 7 hours
"Think about the sustenance you'll need to match your exertion levels and what will be most digestible," Bast says. Her go-to hot beverages include apple or pear slices steeped in cider with maple syrup, white pine tea, and spruce needle tea. For hot food, Bast suggests bone broth, veggie broth, or other soup which you can add proteins to. For something heartier, she suggests a casserole or stew.
Best Budget: Mira Vacuum Insulated Stainless Steel Lunch Thermos
Comes with travel spoons
Easy to clean
May rust after frequent use
For a leakproof and sweatproof vessel on the cheap, look to MIRA’s Stainless Steel Lunch Thermos. It’s easy to clean by hand due to the larger opening at the top and the rubber ring inside of the lid can be removed for more adequate scrubbing to prevent mold accumulation.
The exterior color selection includes muted hues, such as pearl blue, Hawaiian blue, and light pink, which gives this product line a similar aesthetic to more expensive brands currently on the market. It has an average heat retention of approximately five hours and a cold retention of up to 10 hours.
Capacity: 17 ounces | Heat Retention: Up to 5 hours | Cold Retention: Up to 10 hours
"If you happen to be in a snowy situation after you've consumed your hot thermos items, fill it with clean snow. The residual warmth will help melt it ensuring you have more water at the ready." — Kate Bast, Nature and Forest Therapy Guide and Founder of Shinrin-Yoku Madison
Best for Travel: Hydroflask 12-Ounce Thermos Food Jar
Limited color selection
The leakproof Hydro Flask Insulated Food Jar is just as sleek as the company’s beverage-only models. The durable exterior was crafted with outdoor adventures in mind, so it's quite popular with nature and camping enthusiasts, and the 18/8 stainless steel interior ensures no flavor transfer or lingering odors.
Available in multiple sizes, start small with the 8- or 12-ounce container, and then upgrade in size over time if an expanded collection for a family is needed. Just keep in mind that the 20- and 28-ounce versions have higher price points. That said, this should keep your food warm for at least four hours. Some reviewers have even reported excellent heat retention for up to 12 hours.
Capacity: 12 ounces | Heat Retention: More than 4 hours | Cold Retention: N/A
"Always have another thermos or two [in the car] of what you brought into nature with you. You'll be glad to have it and be more likely to consume what you need on the trail knowing there's more waiting at the trail's end." — Kate Bast, Nature and Forest Therapy Guide and Founder of Shinrin-Yoku Madison
For a decently sized thermos that will keep foods, such as soup, stew, and pasta, warm for up to an impressive nine hours, look no further than the Thermos Stainless Steel King Food Jar. Kids, on the other hand, will love the fun colors and cool touch of the wide-mouthed Thermos Foogo Vacuum Insulated Stainless Steel Food Jar.
What to Look for When Buying a Hot Food Thermos
Food thermoses tend to be shorter and wider than drink thermoses. This is so you're able to pour contents, such as soup, into the flask—and eat out of it as well. Most have a twist-on lid, which helps prevent spills. Some thermoses will have additional seals or interior lids for further spill protection.
Stainless steel is the preferred material for thermoses. It won’t absorb color or scent from hot food that is stored in it for a long time and cleans easily. An inner flask is surrounded by a partial vacuum that won't conduct heat away from the flask, keeping the contents warm. An outer case, usually also steel, allows you to hold the container without condensation or burning your hand. The outer case may also be treated with a coating or surrounded by plastic.
Even inexpensive models tend to be vacuum-seal stainless steel. However, the vacuum-seal method can be used with other materials like glass and plastic. Because they are not as durable as stainless steel, they are not recommended.
The size of a thermos largely depends on what you want to use it for. Most thermoses for adults tend to be around 16 ounces, and ones for children are a little smaller. The food will cool down faster if there is excess air in the thermos, so if you want your food to stay hot for several hours, you'll want to use the best size thermos for the amount of food you're putting in it. If you just want the option for a small soup bowl at lunch, you can go with 10 ounces or smaller. If you want to carry a hearty meal in your flask, 16 ounces is likely the better fit.
Thermoses tend to be fairly affordable, and you can typically expect to get a long-lasting one for somewhere between $15 and $30. The more expensive models may boast more fun colors, an extra-strong seal in the lid, or certain accessories, but they all will use the same stainless steel vacuum-sealed design.
Thermos is synonymous with the product it produces—thermoses. But unlike Kleenex and Tupperware, Thermos has not been able to maintain the trademark on the term "thermos." The Thermos company, first started in Germany, was the first to figure out how to take industrial vacuum-sealing techniques and apply them for home use. Today, Thermos makes a wide range of insulated containers, from flasks and mugs to coolers and lunchboxes.
Designed for the outdoors, Hydro Flask’s powder-coated flasks and containers are designed to stand up to heavy wear and tear. Available in a wide array of colors, they also come with a lifetime warranty.
A stainless steel thermos is relatively easy to clean up. Because it won’t absorb scent or color from your food, you can treat it like you would any other dirty dish and wash it with soap and water. Many thermoses are dishwasher safe but not all. This isn’t because of the material but the construction: Dishwashers may mess up the vacuum seal. Interior lids and other accessories, like collapsible forks, may also require additional hand-washing to get rid of built-up grime.
How do I choose what type of thermos to get?
Before purchasing a thermos, narrow down a preferred size and what it will most frequently be used for. This could range from beverages, like coffee and tea, to meals that need to survive a long day and transport to after-school clubs and sports practices. Perhaps durability is the top concern for long outdoor treks. Check customer reviews to read common raves and complaints about each manufacturer’s products.
How does a thermos work?
Using a stainless steel vacuum-sealed design, an inner flask maintains contents at a consistent temperature, since warm or cold air cannot easily penetrate or escape from the flask. The outer material, usually made of hard plastic or steel, allows the thermos to be comfortably held and transported without liquid leaking out.
How long do thermoses keep contents hot or cold?
High-quality thermal flasks can keep food and beverages warm for as long as a full 24 hours. More economical brands will typically retain the original temperature of contents for four to six hours.
Why Trust The Spruce Eats?
Rachel Werner teaches culinary writing through Hugo House and has been selecting food-based businesses for editorial coverage for over six years. Her product and restaurant reviews, food styling, and photography have appeared in a variety of regional and national publications including Fabulous Wisconsin, BRAVA, and Hobby Farms Magazine. For this roundup, she interviewed Kate Bast, nature and forest therapy guide and founder of Shinrin-Yoku Madison.