Though there are a lot of options out there for an insulated thermos, the primary purpose, and the main selection criteria, should be how well they keep hot beverages hot, and cold beverages cold. Tim Schofield of Ritual Coffee Roasters in San Francisco also recommends considering the ease of cleaning the thermos, as well as making sure the material used in the thermos doesn’t change the flavor of the beverage. Annelies Zijderveld, author of the cookbook “Steeped: Recipes Infused with Tea,” takes it a step further and recommends keeping different thermos for different beverages like tea and coffee to prevent any sort of cross flavor contamination. Of course, I wanted to find out which coffee thermos comes has all the criteria: keeps the coffee hot, holds enough coffee to keep me caffeinated, is easy to use, and looks good. With these criteria in mind, here are our picks for the best coffee thermoses available. What We Don’t Love: Small narrow body makes it harder to clean inside, small locking switch can be difficult to use Deceptively small and thin, the Zojirushi vacuum insulated mug was the standout for its lightweight use and vacuum insulated heat retention. Unlike other travel thermoses, the Zojirushi not only maintains the heat of the beverage over an extended period of time but was easy-to-use with a simple flip top, and easy to carry around. During testing, the Zojirushi went from an initial hot 208 degrees to 185 degrees in three hours—a loss of just 22 degrees. Other thermoses were either bulkier and less convenient or lost significantly more heat within that time period. The Zojirushi lid also clicks shut, keeping spillage to a minimum, with a locking switch on the side to prevent accidents. The lid comes completely apart, making cleaning it easier than other thermos mugs, though the narrow skinny chamber inside can be more difficult to clean than other wider mugs. A simple cleaning brush can solve that issue, and that’s a small sacrifice for a portable commuter and travel mug that is so well insulated. Price at time of publish: $50 for 16-ounce sizeSizes: 12 fluid ounces, 16 fluid ounces, 20 fluid ounces | Material: Stainless steel and BPA-free plastic | Dishwasher Safe: No  What We Don’t Love: Reusable straws difficult to clean, gasket feels a bit cheap and may wear out faster With a sleek powdered coated painted metal exterior, that comes in a variety of trendy colors, the Iron Flask not only is appealing to the eye but keeps your hot beverages hot and your ice cold drinks cool. With a heat loss of only 20 degrees over 3 hours (from 208 degrees to 188 degrees) during testing, the insulated thermos functions surprisingly well for the price point. It also performed well with iced coffee. Two hours after making my iced coffee, the cubes were still in there, keeping everything cool. On top of that, the thermos comes with three different types of lids, effectively turning one bottle into three different types of bottles. One lid is a standard screw-on lid, perfect for drinking cold water or for going on a hike where you need a secure top. One lid has a flip-up built-in straw for easy drinking. And the other lid has a standard hole opening similar to other travel coffee thermos. Some consumers complained that the thin metal outside is easier to dent than other thermoses and the plastic and rubber gasket parts on the lids do feel a little flimsy, which may cause some concern for long-term usage and wear. But those who are on a budget should seriously consider this insulated thermos. Price at time of publish: $25 for 22-ounce sizeSizes: 14 fluid ounces, 18 fluid ounces, 22 fluid ounces, 30 fluid ounces, 40 fluid ounces, 64 fluid ounces | Material: Stainless steel and BPA-free plastic | Dishwasher Safe: No  What We Don’t Love: Big and heavy, limited old school colors selections Stanley is a much-beloved old-school standard for vacuum insulated thermos bottles. And their wide-mouth bottle stands up to their brand heritage. Holding up to 2.5 quarts of liquid, the vacuum-insulated bottle is a mammoth beast of a bottle. But it maintains the heat, dropping a mere 13 degrees from 208 degrees to 195 degrees over 3 hours when tested. Even more impressive, the temperature dropped down to 148 degrees in 24 hours. This means you can easily make and bring a day’s worth of coffee for a group outing and still enjoy it hot. Stanley bottles are also known for their durability, but that comes at a cost. Expect a heavy bottle to lug around with you. But know that it’s practically indestructible, taking drops and kicks and tumbles without damage. And if the off chance that it does get damaged, the lifetime warranty means you can get it repaired or replaced. It’s also one of the only thermos bottles on this list that are dishwasher safe. Price at time of publish: $52Capacity: 2.5 quarts | Material: Stainless steel and BPA-free plastic | Dishwasher Safe: Yes  What We Don’t Love: Thin edge feels sharp on the lip, fully removable lid means you need two hands to use If you’re the coffee snob that only grinds your freshly roasted single-origin beans in a burr grinder before making your pour-over or French press, you most likely want a coffee thermos that fits your coffee lifestyle. Enter Fellow, an innovative coffee product company, that designed the Carter Move Mug, with coffee enthusiasts in mind.  The Carter Move mugs come with a standard double-lined vacuum body that keeps the coffee warm, with a small drop in temperature from 208 degrees to 181 degrees in 3 hours. But it’s the other details that set this thermos apart. A ceramic-lined interior ensures that it doesn’t impart any metallic flavor and easily cleans up without residual odor or oil. Even better, the mug has a snap-in splash guard, which looks a bit like a sink catch drainer. This guard helps minimize splashes while the mug is in your car cup holder, so sudden stops and turns aren’t a coffee disaster. The one downside of this mug is the screw-on lid, which requires you to use two hands to seal the lid or leave it open for drinking one-handed. However, there is an optional open-top sip lid that you can purchase for one-handed drinking, if you wish to upgrade. Price at time of publish: $35 for 16-ounce size Sizes: 8 fluid ounces, 12 fluid ounces, 16 fluid ounces | Material: Stainless steel, BPA-free plastic, ceramic interior coating | Dishwasher Safe: No  What We Don’t Love: Expensive, small capacity for size If you’re looking to splurge on a travel mug, the Ember Temperature Control Mug is your new best friend. Unlike other mugs that use vacuum technology to keep your beverage warm, resulting in a slow drop over time, the Ember has an internal heating element to keep your beverage at a consistent temperature of your choice. When I tested it, it lived up to expectations, keeping the coffee at 145 degrees. The mug charges and will keep beverages anywhere from 120 degrees to 145 degrees, a gentle temperature that will keep your coffee warm without scalding it. The heating battery lasts for up to 3 hours, or longer if kept directly on the plugged-in charging platform. The outside of the mug has a digital touch display that allows you to adjust the temperature intuitively, though you can also use a mobile phone app as well via Bluetooth. The top is a push-to-open lid that makes it easy to drink from and the entire mug is a handsome addition to your work desk. You might be like me though, a little scared to bring this very pricey mug into the car or on your commute. It fits in my car’s cup holder, but I would be extra cautious carrying this around. Price at time of publish: $200Capacity: 12 fluid ounces | Material: Ceramic coated metal interior, soft-touch plastic exterior, internal heating elements, lithium battery | Dishwasher Safe: Body handwash, lid dishwasher safe

What Are the Other Options?

How We Tested

The first test was to simply pour hot coffee into the thermos, take the temperature, and let it sit. At the 2-hour and 3-hour mark, I retook the temperatures to see how much heat had been lost. The second test was with iced coffee. After two hours in the thermos, how much ice, if any, was still there. I also tested to see if the thermoses fit in my car’s cup holder, and checked how comfortable drinking from them was. Lastly, each was cleaned thoroughly.

What to Look for When Buying a Coffee Thermos

Heat Retention

The number one thing to look for in a thermos is how well it retains the heat of the beverage. Keep in mind that larger thermoses often will help retain heat more since hot water has a high heat capacity—the more water there is in the thermos, the slower it will cool down. Look for a double-walled vacuum-sealed thermos that will keep your hot beverages hot and your cold beverages cool.

Size

The size of a thermos is up to you, but keep in mind how you plan on using it. Larger thermoses are convenient, but they are bulkier and often weight more. Will you be drinking from the thermos at your desk or commuting? Do you need a thermos that fits in your car cup holder or will you be taking it on public transit? Do you plan on going camping or hiking with it? Do you drink large amounts of coffee or tea or do you only need a single serving? All of these should influence the choice you make.

Style

Thermos come in all styles as well as sizes. Depending on how you plan on using your thermos, you will want to select a travel thermos that fits your lifestyle. A smaller, more lightweight tumbler-style thermos might make more sense for commuting or light hiking, while a more robust bigger thermos with a screw-on top would be optimal for day-long adventures or overnight camping. Also consider if you’d prefer your thermos to have a handle, if you like using a tumbler, or if you want to splurge and get one that actually keeps the liquid at a steady temperature via heating elements instead of just a vacuum-sealed chamber. 

Ease of Use

Along with the style of thermos, is the consideration of how easy the thermos is to use. Some thermoses have switches and mechanisms to prevent spillage or use completely removable lids that screw on. This is great for throwing the thermos in your backpack or messenger bag as you don’t have to worry about accidents. But it can also be more cumbersome, as it requires two hands to use the thermos. If you aren’t accident prone and don’t need that security, or you want to drink your hot beverage using one hand, select a thermos that has a flip lid or a button release. And take note of the way lid is designed. Some lids comes apart or are easier to clean than other lids. 

How long is brewed coffee fresh to drink?

Ideally, you want to drink freshly brewed coffee within 30 minutes. After that, the coffee will start to oxidize and lose flavor. To prevent this from happening, you can pour the coffee into a vacuum-sealed thermos with the lid tightly sealed immediately after brewing. This will prevent air from breaking down the volatile flavor molecules in the coffee. Do not keep the coffee on the burner or heater. This will just burn the coffee and give it a bitter stale taste.

How do you get the coffee smell out of a thermos?

If you can clean the coffee thermos immediately after use with warm soapy water this will help prevent the coffee from staining or creating a smell. But over time, the thermos might start to develop an odor. If this happens, try adding a 1/2 cup of white vinegar to the thermos and sprinkling in 1 tablespoon of baking soda. The liquid will foam and fizz. Gently swirl or stir the liquid until the foaming subsides, and then fill the thermos to the top with hot water. Do not put the lid on but leave the thermos to sit for 10 minutes in the sink, in case more foaming occurs.  Then grab a bottle brush and scour the inside of the thermos to remove any oil and coffee residue. Empty and rinse thoroughly several times to make sure there’s no residual vinegar or baking soda. Make sure to give the thermos a good sniff to see if you can smell any more vinegar. If you don’t, you’re good to go. Let it dry completely before use.

Why Trust Simply Recipes?

This article is written by Irvin Lin, a cookbook author of Marbled, Swirled, and Layered and an ongoing contributor to Simply Recipes. He runs his own blog Eat the Love, is a professional recipe developer and worked as a barista at an independent coffee shop right out of college. He continues to be an enthusiastic coffee drinker, along with his coffee snob husband and has tasted and traveled all over the country and various different continents, sipping and sampling different beans and brews. Both his husband and he personally tested various different thermoses for heat retention, quality, and ease of use. Read Next: The Best Cold Brew Coffee Makers