Best Thermoses and Thermos Flasks Reviewed and Rated
There is nothing handier than a reliable thermos. What makes these products fantastic is that they are the perfect companion to tuck into your backpack. What makes a thermos different than your average tumbler is that it has insulated walls and a tight lip to keep your fuel at your desired temperature.
The styles that we selected for our list can achieve a myriad of purposes. You can use them for warm lunches when backpacking or camping in cooler temperatures or they can keep your water cold of those super hot days. The brand of Thermos is the leading brand in the market, but there are a few other brands that are worth checking out.
In this guide, we have compiled a list of some of our favorite thermoses to make your next outdoor excursion as comfortable and fun as possible!
In a Hurry? The test winner after 6 hrs of research
Best Thermo Flasks Reviewed
1. Thermos Stainless King
No relief valve
Coming in at the very top of our list is this thermos design from the most the reigning champion- Thermos. The reason that we selected the Stainless King for our number one selection is that it has a sleek design that works for various occasions. It sports the classic design that is made to fit into just about anywhere without taking up all that much room.Read more
As with any Thermos product, you know that it is made from high-quality materials that won’t leak or drip all over your gear. In fact, it may be the last thermos that you will ever need to buy! It is made from durable stainless steel with a handle along the side for easy carrying.
Users love that this thermos can really keep beverages hot or cold for up to 24 hours of packing it! It can achieve this task by using a vacuum seal stainless steel double chamber that prevents that weather from the outside affecting the contents of your container.
If you are in the market for the most tried and tested thermo flask out there on the market, this design from Thermos is one of your best options. It has a basic bullet design that comes in midnight blue, black, and stainless steel.
2. Hydro Flask
Will not sweat
Hard to open lid
The great thing about this thermos is that it doesn’t actually have the standard look of a thermo flask. All of the internal components are the same to keep your food or drink cold or warm as you travel, but it has a sleek and modern look to it. Plus, it is offered in a lot of fun and bright colors that stand out from the rest.Read more
What we immediately noticed about this design is that it doesn’t have that standard look to it. It has a design that looks like a simple jar, but there is real magic happening on the inside. While the outside is made of fun colors, the inside has a double layer of stainless steel to keep your food hot or cold without being hot to the touch.
It is offered in a lot of fun colors that include bright blue, pink, red, green, silver, and black. There are no handles along the side and have a very simplified exterior. What’s great about the style of the Hydro Flask is that you won’t have to worry about the outside sweating over all of the gear in your backpack.
If you want something that is a little more simple and stylish over the standard classic designs out there on the market, this is one of your better options. We love the sleek bottle design that has a durable layer of stainless steel that really keeps your food or drink at the perfect temperature.
3. Stanley Adventure
Next to Thermos, Stanley is one of the most trusted names out there on the market. What we liked most about this thermos is that it has a few extra features that will help make your like just a little bit easier. It is made from high-quality materials you can rely on from Stanley, and it will be the last thermo flask you may ever need to buy!Read more
Simplicity is the name of the game when it comes to any Stanley product. They don’t want to bog their practical designs down with any gimmicky bells and whistles. That’s why users love the design of the Stanley Adventure thermo flask. It has a stainless steel double layer that keeps foods hot or cold for up to 12 hours.
It has a small and stout frame that makes it easy to pack into even some of the smallest spaces. What’s great about this design is that there is a spoon that is mounted along the side of the container so you will never be without the proper eating tools! Plus, it has a stainless steel loop along the side so you can attach it to the outside of your pack or even your belt loop.
If you are in the market for something that comes from a trusted brand that will keep your foods hot or cold, this is an excellent option. Stanly products may not have a lot of extra bells and whistles, but they are designed to last for years and years of outdoor adventures.
Average heat retention
Fijoo may not be a brand that you have heard of before, this thermos is worth a look! What users love about this style from Fijoo is that it is incredibly simple and effective. It has a long and slender design that fits just about anywhere, and it is made from quality materials that are built to last.Read more
What makes this thermos a little different is that it sports a little bit more than just a simple double layer of stainless steel. In between the layers of insulating stainless steel is an additional layer of copper. While stainless steel is the perfect insulator, copper just adds just a little bit more protection.
Another thing that users really love about this design is that it has an incredibly slim and simple design. The tight-fitting BPA free lid will not leak on your gear, and it fits incredibly tightly. The outside of the bottle will not sweat and won’t feel hot to the touch, no matter what you fill your bottle up with.
For those that are in the market for something that is sleek and simple, this thermos flask from Fijoo is worth a look. It may not have the same initial brand recognition as some of the bigger brands, but many previous users will tell you that they are worth checking out.
5. Stanley Classic
Difficult to open
Stanley is making our list yet again with this classic design. If you asked a 10-year-old to draw a picture of a thermos, the Stanley Classic is what they would draw! It has all of the features that you want in your thermos flask, and it is made from high-quality materials that will hold up incredibly well over time.Read more
The exterior of the Stanley Classic has a retro green shell with a handle along the side and a stainless steel base and top. This high-grade stainless steel is rust-proof, so you don’t need to worry about getting caught out in the elements. The interior has a double layer of stainless steel that works overtime to keep your beverages hot or cold.
What we liked most about this thermos is that it is able to keep beverage hot or cold for an impressive 15 hours! While many brands only claim to keep beverages hot for 12 hours, the Stanley Classic goes just a little bit longer. Plus, the entire unit is backed by a lifetime warranty if any of the components fail on you.
If you are in the market for a thermos from a trusted brand that will keep up with you on years and year of fishing trips, this design from Stanley is one of your best options! Plus, it is durable enough to take with you on those long-distance runs. It has a retro design that will never go out of style, and it comes from one of the most trusted brands out there.
Many fun colors
Hard to clean
What we liked most about this design from MIRA is that it has a contemporary style that doesn’t look like your grandfather's thermos. However, do not let looks deceive you, it is made from the same high-quality materials as some of the bigger brands out there on the market.Read more
The exterior design of this thermos flask is fun and playful. It has a very sleek and modern design that fit’s easily into most backpacks or totes. It is offered in fun colors that include bright pink, blue, green, yellow, and purple. Plus, the exterior has a matte finish for easy handling that is sweat-proof as well.
The inside is constructed with MiraGuard Technology that helps keep hot foods hot and cold foods cold. It has a double layer of 18/8 food-grade stainless steel. This means that it will keep your foods at your desired temperature, and it also will not transfer flavors into your food or drink.
If you are in the market for something that is made from classic materials that boast a modern exterior look, this is one of your best options. Users love that it is able to keep foods at your desired temperature for up to 12 hours!
2 cups included
If you are looking for something to carry your water throughout the day that will actually keep it hot or warm, this is one of your best options. While it isn’t made to hold food, it is a great option to hold water or coffee while you are out camping or going for a long hike.Read more
The very first thing that we noticed about this bottle is that it has a modern and sleek finish, while still having all of the functionality of a classic design. It has a stainless steel top and bottom that is rustproof and has a unique shape that is easy to carry. It comes in two different colors which include a glossy black and a glossy white.
The inside is constructed of dual layers of stainless steel that are designed to keep cold beverages cold for up to 24 hours, and hot beverage hot for up to 12 hours! The lid is composed of plastic that is BPA-free, and stainless steel is free of any harsh chemicals. You can feel good about the eco-friendly materials used to make this sleek and modern thermos.
If you are in the market for something that is made from high-quality materials that are built to hold up well over time and keep your beverage at the ideal temperature, this is a great option. While it may look delicate, it is a great option to take with you to the office or camping!
8. Thermos Foogo
Easy to clean
Limited heat retention
Thermos is making our list yet again with this really clever Foogo thermo flask. While many of the Thermos options offers up that classic design, the Foogo has a style that is a little bit more modern. This design is perfect for keeping cold foods cold or warm foods warm for up to 7 hours.Read more
It sports a squat and stout design that is easy to pack into a tote or backpack to take with you on the go. The dual-layer of stainless steel will not sweat all over the contents of your backpack, and it will always feel cool to the touch. A layer of rubber on the top and bottle also keeps it from rolling around and will help you grip it in your hands.
The downside of this unit is that it only keeps foods cold or hot for a maximum of 7 hours. In comparison to over Thermos flasks, this is a much shorter period of time than most. This makes it a great option if you are simply packing a lunch or going to a walk in the park in the afternoon and want to bring along a snack.
If you are in the market for something that is a little more casual that comes from a trusted brand, this is a great option. What we loved most about this design is that it is made from high-quality materials that are resistant to rusting and denting- no matter how much you throw it around!
Gret heat retention
Smaller than most
What we liked most about this thermos from Isosteel is that it is made from high-quality materials that are great to take with you on all of your outdoor adventures. It has an exterior design that fits perfectly in any backpack or tote, and a tight-fitting lid that holds in heat and will not leak.Read more
What we liked about this design is that is is made from food-quality stainless steel that keeps for beverages tasting fresh. It is also made from materials that are chemical-free and FDA approved, and the plastic lid is BPA-free.
The exterior shell of this design makes it a cinch to take with you on the go. It has a long handle along the side that allows you to carry it by the handle, and the long and narrow design fits great into any backpack or tote. Plus, it comes with a built-in cup that is mounted to the top so that a hot cup of coffee is only a pour away.
If you are in the market for something that is made from high-quality materials that hold up well no matter where your travels take you, this is a great option. It has a sleek and simple frame that makes it packing it into a backpack a breeze.
10. Stanley Classic Legendary
Great heat retention
If you want all of the quality from a Stanley product, but you want it to be just a little bit more modern and slim- this is one of your best options. It is made from high-quality stainless steel that boasts a lifetime guarantee if anything goes wrong with your product.Read more
The very first thing that we noticed about this design is that is has a narrow and sleek design that makes it easy to pop into a backpack or tote bag. Weighing in at 1 pound, it is a little heavier than most. However, this extra weight is due to the extra layer of steel found on the interior.
A double layer of stainless steel keeps a cold beverage cold for up to 4 days, and warm beverages hot for up to 20 hours! If you are heading out for a long hike in the woods or if you are going on a camping trip, this is one of the best options to bring along with you. It is just important to note that it may weigh you down a little bit.
If you are in the market for something that is made from high-quality materials that will hold up quite well over the years, a Stanley product is the way to go! What we loved most about this thermo flask was its simple design and the quality of steel that is used.
Criteria Used for Evaluation
The end goal here is to keep warm things warm, and cold things cold.
No matter if you are carrying a container of soup or just ice water, it is important that these products actually do their job! There were a few things that we kept in mind when determining whether or not a product is effective or not.
The most reliable method to determine effectiveness is to read previous user reviews. We combed through hundreds and hundreds of user reviews to determine if a product can actually keep food hot. From what we gathered, most products hod true to their claims of keeping food hot or cold. There were just a few products that fell short, and we did not include them in our list.
Another way that we determined whether or not a product would be effective was to look at what is found on the inside of the container. It was an absolute must that each and every thermos has a double layer of stainless steel. If it doesn’t have dual layers for insulation, it is a tumbler and not a thermos!
The lid is another point of contact that we considered for determining how effective a product is. While we can gain a lot of information from the materials used for the lid, we can also gain a lot of insight when reading user reviews.
Many users complain that the top is incredibly difficult to open and report this as a negative feature. While it is frustrating not to be able to open your lid, this means that your thermos is actually working! In order to keep your contents hot or cold, the lid needs to create a vacuum seal. If it is difficult to open, it means that it is actually working!
High-quality materials make all of the difference.
When selecting products for our list, we wanted to make sure that we found products that were made from the best materials. When it comes to thermoses, stainless steel is the way to go! In fact, we made sure that each and every design on our list was made from stainless steel because it is the best at retaining heat or cold.
We chose to select products that were made from food-grade stainless steel. What makes it food grade is that it isn’t made with harmful chemicals that may seep into your food or beverage and affect the taste.
On the inside, we liked products that used two layers of stainless steel to create a barrier between your hands and the contents of the thermos. Some products even add an additional layer of copper in between layers of stainless steel. Copper is a great conductor of heat and cold, so it holds the temperature to keep it hotter or colder for longer periods of time!
As far as the lid is concerned, most products out there on the market use plastic lids. Plastic is better because it grips to the stainless steel base a little better than a steel lid. Plus, it is a little bit more pliable that makes create a vacuum seal a little easier.
When selecting plastic lids, we wanted to make sure that we selected plastic that was BPA-free and free of any harmful chemicals. This allows you to use it and wash it over and over again without the lid releasing harmful chemicals into your food or beverages.
Above all else, we wanted to ensure that all of the materials used were chemical-free and safe to use over and over again. That’s why chemical-free stainless steel and BPA-free plastic lids are incredibly important.
When we talk about capacity, we are talking about how much tasty goodness each thermos can hold.
Size is important, but bigger isn’t always better. Below, we have gone into a little bit of detail about what size is right for you.
From our research, most standard sizes measure to carry about 24 ounces. This equates to about 2 cans of soup with a little extra room at the top. Users love this size because it is the perfect size for a good meal, or a good portion of coffee to share with your friends.
On the lower end of the size spectrum is those that carry about 10 ounces, like the Foogo from Thermos. Smaller sizes may not carry as much food or coffee as the larger sizes, but they are great for packing into small space. If you have limited room in your backpack or tote, the 10-ounce options are one of your best options.
The size that you need boils down to a matter of personal preference. If you are away from civilization for extended periods of time, a larger 24-ounce option may be your best bet. If you just need something to get you through to lunch, the smaller 10-ounce design is better for your needs.
It is also important to keep in mind that dual layers of stainless steel are not light! The larger options that you select mean the heavier it will be. For reference, the larger Stanley Classic weighs in at about 1 pound when it is completely empty
A few key features help make your life just a little bit easier!
We wanted to select options that not only keep your food and drink at the right temperature, but also that made it easier to tote around. Below, we have gone into a little bit of detail of some of our favorite additional features.
Belt loop: A mounted loop just below the lid makes it just a little bit easier to carry around. Whether you are on a really long hike or just camping with some friends, a loop makes it easy to affix to your pants or backpack. Some users even attach a lanyard to their thermos and hand it around their neck.
Copper lining: A copper lining between the dual layers of stainless steel is a great feature. While it may increase the weight of your thermos, it serves an excellent purpose! A layer of copper is a great way to keep your food or drink hotter for longer periods of time.
Utensils: We love products that have built-in utensils! How many times have you been out camping, only to find that no one remembered to bring a cup or a spoon? Many of the food jars out there on the market have spoons mounted right at the side so that you always have it on hand.
We also liked thermoses that had a cup built right onto the top of the unit. This allows you to really enjoy your piping cup of coffee instead of drinking it right from the container.
Ease of Use
When we discuss how easy it is to use, we are talking about how easy it is to clean.
A thermos is like a portable dish, and you have to wash dishes after every use! The bad news about a thermos is that cleaning it can prove to be a little difficult. The last thing that you want is the ghost of your previous coffee haunting your chicken noodle soup!
That why we made sure that we selected designs that were considered to be easy to clean. The shape of your standard thermos can prove to be a little challenging to get into all of those little nooks and crannies, but there are a few things to make your life just a little bit easier.
The first thing that we looked out for was whether or not each design was considered to be dishwasher safe. Life just gets a little bit easier when you leave the hard work to the cleaning robots in your home!
One important thing to note is that a large majority of these products aren’t considered to be dishwasher safe. Even some of the higher-end Thermos brand models aren’t safe for the dishwasher! Brands such as Stanley, however, are fine to toss into your dishwasher!
Another thing that made these designs just a little bit easier to clean is a wide mouth. When they have mouths that are a little more narrow than most, sticking a sponge down into the bottom is a little bit difficult. When the mouth is wide, it is a lot easier to get into all of those nooks and crannies to really clean it with a sponge.
It is incredibly important that you are able to really get your thermos clean before each and every use. To keep every subsequent meal tasting like the coffee you carried on day one, it is important that you really get it spotless between uses!
Expert Interviews & Opinions
The great thing about a thermos is that you can use it for just about anything! You can use it for coffee on one day and soup on the next. However, to avoid the unpleasant coffee-flavored soup, be sure you clean it regularly! We suggest a mixture of vinegar and baking soda with a generous amount of piping hot water.
The original thermos wasn’t designed by an unhappy camper, but rather a scientist studying cryogenics. Scottish scientist Sir James Dewar invented the vacuum-sealed convection container in the late 1800s to conduct chemical experiments.
A thermos isn’t something reserved for campers and boy scouts, they are also perfect for daily use as well. Fill it up with your daily helping of water and sip on it all day long, because staying hydrated is important! The seal will ensure it is just as ice cold at the end of your day as it was in the beginning.
Other Factors to Consider
A good thermos should be a staple of every home. It is a great tool to have on hand when you go on outdoor adventures on cool fall days or hot days in the middle of the summer. What we love about a good thermos is that the dual layers of stainless steel keep prevent the container from sweating. This means you can load it up with ice water, pack it into your backpack, and not have to worry about your gear getting wet from condensation.
Plus, a thermos can be used for just about anything. If you are on a long hike in the woods, it can prove a perfect place to store a snack or a coffee break. Smaller designs are great for packing a light lunch before heading into the office.
If you don’t like the happy camper designs of many of the classic options, more modern designs like what we saw from Hydro Flask is a great way to bring a little bit of style to your day.
No matter where your travels take you, it is important to always be prepared!
Frequently Asked Questions
q: Why do I need a thermos flask?
If you ever found yourself in a situation where you longed for a hot cup of coffee while fishing or on a camping trip- you need a thermos! The great thing about these products is that they do a great job of keeping cold things cold and hot things hots for hours at a time.
The versatility of these simple containers makes them something perfect to use all year-round. Plus, many offer modern designs that make it something that you will want to use to simply pack your lunch or extra coffee before you leave for work in the morning. Plus, due to the fact they keep water cold, they are a great companion for those brutal CrossFit training sessions to cool you off!
If you are the skilled outdoorsman or just someone that loves to carry hot coffee with them all day, a good quality thermos is a great product to have on hand. You never know when you will need it!
q: Are they easy to clean?
For the most part, they are pretty easy to clean. There are some designs out there on the market that are much easier to clean than other designs. If you don’t want to be bothered with difficult to clean options, there are a few things to consider.
For super-easy cleaning, we suggest selecting an option that is dishwasher safe. There are few brands out there that boat dishwasher safe options, however. Stanley is one of the only brands out there on the market that is safe to put into the dishwasher.
Another thing to keep in mind if the wideness of the mouth. Keep in mind that you will want to it be large enough to fit a sponge into in order to really clean out all of the nooks and crannies.
It is really important that you give it a good cleaning after every use! If you don’t, your next meal may taste like the coffee you packed the day before.
q: How do they work?
It’s pretty amazing how well these containers keep hot food hot and cold food cold, even in extreme weather. So, how exactly do they work? The answer to this question is pretty simple.
Most designs use a combination of vacuum seating and convection heating and cooling to keep your drink at the ideal temperature. Lids that fit incredibly tightly keep your liquid from moving around. The more it moves, the quicker it will cool.
Another feature of a good thermos is a dual layer of stainless steel. The interior layer is designed to reflect the heat to keep it from escaping to the outside of the bottle. Not only will it keep your beverages hot, but it won’t make the outside of the bottle hot to the touch!
q: Can I pack them into my backpack?
Absolutely! One of the things that we love most about these thermoses is that they are great to toss into a backpack or even in your gym bag for when you need it. Other bottles such as tumblers will sweat on the outside when filled with ice water. This ice water will get all of your gear in the side of your pack damp- which is bad news!
The dual-layer of stainless steel is great because it keeps your bottle from sweating. Feel free to pack it with some of the coldest ice water you can find and don’t worry about the status of your gear in your backpack!
q: Do they have to be made from stainless steel?
Yes, all thermoses need to be made from stainless steel in order to be effective. Bottles that use plastics may be heavy-duty and durable, but they do not offer the same level of convection that stainless steel can offer.
If you find a thermos that isn’t made from stainless steel, run away! It means that it is a product that cut corners to come in at a lower price point that will not be effective.
However, many of the modern food jar designs have a plastic coating on the outside. Brands such as MIRA use a matte plastic coating on the outside of their containers. However, the inside of each bottle is composed of a dual-layer of stainless steel to provide excellent convection.
q: Why is it important to be BPA-free?
Since the 1960s, BPA has been used in the manufacturing of many plastics products used for food consumption. While the FDA found it to be completely safe to use, recent studies have changed how science views BPA.
Recent studies have found that as users wash their plastic products, BPA will slowly start to seep into the food that the container fills. Over time, exposure to BPA over long periods of time have negative effects on blood pressure, children, and reproductive health.
Due to the fact that the research is so new, there are few laws that ban the use of BPA in many products. States like California have initiated a ban, but other states have yet to jump on the bandwagon. This means that consumers must use their due diligence to find out whether a product is BPA-free or not.
The good news here is that the products that we selected for our list all use plastics that are considered to be BPA-free!