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If you didn't have time for your overnight oats at breakfast or are trying to eat healthier or cheaper work lunches by bringing your own, there's likely a food thermos designed to meet your needs. Food thermoses, also called food jars or soup thermoses, are typically vacuum-sealed, insulated containers that keep your meals warm or cold at food-safe temperatures for several hours without the aid of electricity or microwaves. Many are designed to prevent leaks (so you can bring soups to work) and resist significant denting when dropped, making them ideal for on-the-go lifestyles.
There is a lot of variety among brands when it comes to how well each food thermos performs, so here are the best food thermoses on the market.
Best Overall: Thermos Stainless King Food Jar
Whether your job includes unpredictable meetings in the office or being exposed to the elements for hours on end, the most important thing about your soup lunch is that it is still hot when you want it. The Thermos brand's Stainless King Food Jar can do just that.
This insulated metal jar holds 16 ounces of soup—or any liquid—and will keep your food piping hot without the container ever being warm-to-the-touch. Available in green, blue, red, stainless steel, and black, the Stainless King includes a built-in spoon and a lid that works well as a bowl.
Best Budget: MIRA Vacuum Insulated Stainless Steel Lunch Thermos
If you want to keep your meals extra hot without breaking the bank, the Mira Stainless Steel Lunch Thermos does the trick quite nicely. Affordable without sacrificing quality, this stainless steel, triple wall-insulated thermos boasts a 17-ounce capacity, so it’s great for holding soups, hot lunches, or snacks of varying sizes. It’ll keep your food hot for up to five hours and cold for up to ten hours.
This premium, durable Mira Lunch thermos is free of lead, BPA, phthalates, and PVC, and it’s very easy to clean thanks to its wide mouth. Customers report that it’s the “perfect thermos for on-the-go” use.
Best for Kids: Thermos FOOGO Vacuum Insulated Stainless Steel Food Jar
The Thermos Foogo food jar provides all of the functionality of a typical thermos, but with the colorful flair and rubber edges that kids will love. The BPA-free container is made specifically for kids—it won’t sweat in the backpack, it won’t spill, and it’s durable. Resistant to scratches and slips, this food jar can even go in the dishwasher.
The stainless steel, insulated container includes a rubber-cover bottom and lid that comes in fun colors like blue and yellow, watermelon and green, or pink and purple. Perfect for hot or cold items, the Foogo can keep soup warm for five hours and fruit cold for seven hours—great for lunch or after-school activities.
Runner-Up, Best for Kids: Thermos Funtainer
When you search for the optimal thermos, you probably have a few criteria in mind, such as affordability, durability, compactness, effectiveness, and design. This simple, yet well-made and popular food thermos is sure to fit the bill and will be a purchase that anyone will enjoy.
The massively popular Funtainer features a stainless steel, insulated body and comfortable exterior. This inexpensive 10-ounce food thermos is compact and comes in vibrant colors with designs inspired by "Paw Patrol," "Pokemon," "Spider-Man," and more. It keeps food cold for seven hours and hot for five.
Best for Travel: Hydro Flask 12 oz. Food Flask
Possibly more fun than the Funtainer is the Hydro Flask Food Flask thermos. This brand’s well-known colorful, matte metal—available in several colors including lava, mint, and mango—insulates your food in a stylish container that doesn't retain or transfer flavors from today's soup to tomorrow's smoothie.
You can get your Food Flask in either a 12- or 18-ounce size. This thermos is designed to be durable and is small enough for nearly any bag, making it an excellent option for any adventure.
Best Stackable: Lille Home Stackable Stainless Steel Thermal Compartment Lunch Box
There are few lunch options better for both kids and adults than the Lille Home Stackable Stainless Steel Thermal Compartment Lunch Box. This set of containers is convenient and stylish. The compact tower looks like one traditional, large thermos, but is actually three individual containers stacked on top of one another.
The Lille Home containers come in stylish green, gold, gray, blue, or pink designs. Along with their appealing exterior, the interior is made with an easy-to-clean stainless steel. Each comes with a foldable stainless steel spoon or cutlery set and an aluminum foil-lined lunch bag for enhanced insulation. The leak- and spill-proof containers total 43 ounces of storage and will keep food warm for two to three hours.
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 to keep food safe 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 keeps contents warm surrounded by a partial vacuum that can’t conduct heat away from the flask. 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. Smaller amounts of food will cool down faster, but if there is excess air in the thermos, the contents will also cool faster. 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, a tiger seal for the lid, or other accessories, but they all will use the same stainless steel vacuum-sealed design.
Aside from skipping the microwave, there’s an important reason to keep your food insulated: Food safety. Bacteria can grow in the “danger zone” between 40 and 140 degrees. The USDA generally recommends keeping hot food hot and cold food cold if it needs to be left out for more than two hours. When looking at thermoses, consider how long you will want it to stay hot—many will keep food hot for up to seven hours. That also means it’s actually better to put foods like soups into a thermos when it’s a little too hot to eat. You can always let it cool with the lid off to get it to a pleasant temperature. Better that than a lukewarm (and potentially dangerous) soup at lunchtime.
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 lunch boxes.
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.