Last Updated on March 22, 2023 by David Michael
Hot Stuff! (and cold too): Best Food Thermos
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A thermos keeps food hot or cold for hours. They’re perfect for bringing lunch to work or school. Bring hot or cold foods on a picnic or road trip. Anywhere you don’t have access to refrigeration or a way to heat up food is the ideal situation for a food thermos. For years I would bring my own lunch to work and these are some of my tried and true recommendations.
What is a Thermos?
A thermos is a container that keeps food and beverages hot or cold. This is achieved through insulation. The best thermos are vacuum insulated. A vacuum insulated thermos is double walled, and the space between the walls has the air removed between them. This vacuum greatly reduces thermal conduction and convection – meaning your hot food stays hot much longer.
What Makes a Good Food Thermos?
A thermos used for food shares the qualities of a regular beverage thermos such as heat retention. Being leak proof is a necessity when tossing your thermos into your bag. Keeping cold things cold is another common quality.
A food thermos also should be easy to fill. The wider the mouth the easier it is to put food into. A larger opening also allows you to eat right out of the container. If a thermos isn’t well designed, the wide mouth will let the heat conduct away much faster.
A thermos used for food should also be easy to clean. They need more than a quick rinse before using them again.
To recap briefly, a food thermos should be:
Excellent at Heat / Cold Retention
Easy to Fill
Easy to Clean
If you’re looking for a hot and cold thermos for food, we’ve got you covered!
The Best Food Thermos – Our Recommendations
This is the thermos that I usually bring with me to work every day. It comes with a folding spoon that stores in the lid. The outer lid adds to the insulation and also can be used as a bowl to eat from. It keeps food hot for 7 hours and cold food cold for 9 hours. The size is perfect at 2 cups. For me, this is the best lunch thermos. I love that this now comes in a great assortment of colors, and brushed stainless steel also. I can vouch for the durability of this one – mine has lasted years.
The thermos also comes in a 24 ounce size. I use this one if I knew I had a really long day and needed more than the 16 ounce size. This size doesn’t come with a spoon, but makes up for it in insulation ratings. The Thermos 24 ounce keeps hot food hot for an impressive 9 hours, and cold foods cold for 12 hours. This is quickly becoming my everyday container, it’s easily one of the best hot food thermos around.
I have an earlier version of the LunchBots thermal food jar. I love this update. The lid is easier to grip, and the new venting feature releases any pressure. This makes it much easier to open. This will keep food hot for up to 6 hours. Not as good as the Thermos brand, but it will certainly keep your lunch hot. The LunchBots is available in a 12 ounce and 16 ounce version, I prefer the larger 16 ounce one.
Designed for kids, the Thermos Funtainer has all the quality of the larger ones. The 10 ounce size is perfect for smaller lunches. This keeps food hot for 5 hours, and cold for 7 hours. Just right for school. I love the fun colors and patterns this comes in. And they also come with a folding spoon. I would use this for an afternoon snack – a small ice cream sundae perhaps.
Stanley is a classic vacuum bottle maker. These are updated versions of their classic designs (no glass – all stainless construction). These are solidly built. Stanley doesn’t give information on how long they will keep food hot. Users report that the Stanley will keep things hot for about 12 hours. This is one of the best thermos for hot food available. The larger 24 ounce capacity is perfect for people that need a bigger serving. I love the hammered finish, but this is also available in a matte black.
How Long Does Food Stay Hot in a Thermos?
This depends on a the design of the thermos. Wider mouths mean faster heat transfer. This is usually addressed with thicker caps, and a double seal – like the Thermos brands have an outer cap. The outer cap not only helps to insulate, it doubles as a bowl.
All of our recommendations keep food hot at least 5-7 hours, some even more. To get the best performance out of your thermos, see our tips.
Tips for Using a Food Thermos
Preheat your thermos before filling it with hot food for the best performance.
I fill mine with hot tap water and let it sit while I heat the food up. Once the food is simmering hot just dump out the tap water and fill the thermos with the hot food. Preheating takes any chill off of the metal interior and really improves how long your food will stay hot.
If I take cold food I put a few ice cubes in the thermos and fill it with cold water first. I let the thermos sit for about 5 minutes before I dump out the water and ice. If I’m packing a chilled soup I’ll add a small ice cube to keep things really cold. By lunch time the ice cube has hardly melted and I just scoop it out with a spoon.
The best foods to use in a thermos have liquid in them. Think chili, soups, and stews.
Always clean your thermos out after you’ve eaten. Try to rinse them with water before putting them back in your bag. Wash them once you get home so they’re ready to go the next morning.
If you’re using your thermos for coffee, check out our post on Best Coffee Thermos for our recommendations.
You may also like our post on the Best Coffee Grinders for French Press and Cold Brew.
For something different, see our picks for the Best Cheese Slicers.