The 6 best coffee thermoses to stay spill-proof and caffeinated

Pros: Lightweight, easy to clean, great heat retention

Cons: Not dishwasher-safe

Dependable, lightweight, and ergonomic, the Zojirushi SM-WR series of thermoses is our top pick. It suits most people's needs without becoming too cumbersome. Zojirushi offers some of the best thermal and pressure technology in the kitchen space, so it's no surprise that their thermoses offer some of the best heat retention and sealing technology we've found.

A two-step opening mechanism ensures that whether it's jostling around on the floor of your car or upside-down in your backpack, it's not going to open. It's also about as light as a water bottle. If you do decide to use it for something other than coffee, it won't weigh nearly as much as most of the other double-walled, stainless-steel, vacuum-sealed picks.

Zojirushi is a little on the pricey side, but the trusty lid, built-in silicone gasket for easy cleaning, excellent heat retention, and lightweight answer promptly for that.

The only downside we see with this model (among others) of Zojirushi's is that it's not dishwasher-safe. You also don't want to leave it soaking, which could cause the interior coating to react.

Pros: Automatically seals after engaging, dishwasher-safe, lifetime warranty

Cons: Not the most sanitary (mouthpiece always exposed), middling temperature retention

If you want what Stanley Classic Trigger-Action Mug devotee and Insider Reviews deputy editor Les Shu calls a "totally klutz-proof" mug, Stanley is your safest investment.

That's because this mug automatically seals after engaging; there's no forgetting to lock it or nominal drippage. To drink, you have to engage and hold the button to allow liquid to flow, which some might find annoying. However, therein lies its faultlessness, and to that point, you can also manage to drink from it one-handed.

Stanley's Classic Trigger-Action Mug held its own in our tests, especially among quick-pouring and flip-top models, which tended to lose heat much more quickly than more solid lids.

The only other potential disadvantage is that the lid is somewhat complex, and that means there are working parts and compartments that can invite mold. Disassemble and clean it regularly, and you won't have any trouble.

The Classic Trigger-Action isn't the lightest, but it's easy to hold and operate one-handed and far from the heaviest.

Pros: Nearly indestructible, great temperature retention

Cons: On the heavier side

Not only does Yeti's Rambler series of drinkware retain heat with the best coffee thermoses on the market, but you can do anything short of driving a truck over it with hardly more than a scratch.

True, they're heavy as heck, and you don't really want to go toting one around all day (at least not the larger-volume models). But whether it's keeping hot things hot or cold things cold, Yeti does its job and then some. The resilience of Yeti's line of drinkware may seem excessive, especially considering the weight. But that heavy-duty steel is precisely what keeps it from denting or shattering in rough-and-tumble situations. 

The Rambler is also BPA-free and dishwasher-safe, as is the series of lids that fit it. (In addition to the included Hotshot Cap, there's the 5-Ounce Cup Cap, the Bottle Chug Cap, the Stronghold Lid, and the Magdock Cap.)

Yeti's Rambler is the model for the intrepid outdoor enthusiast or the car-based commuter who doesn't mind the extra weight. This thermos will easily last a decade or more, but again, it's not for everyone.

Pros: Slim but sturdy silicone carry loop, comfortable edge, easy lid disassembly, lifetime warranty

Cons: Retains smells, loop may fail over time

A coffee thermos is only good if you're willing to carry it, and while there are plenty of models with clips and rings, none are as lightweight and low-profile as Hydro Flask's Coffee. Whether you hang it from a finger or two or strap it to your pack or messenger bag, it does its job without needing a big hunk of plastic. A carabiner can come in handy with this model since it doesn't come with a clip.

Apart from the loop, the Hydro Flask thermos is simple and effective. The lid twists open for drinking and disassembly, there are no funny mechanisms that require a pipe cleaner to sanitize, and the smooth rim is a delight to drink from.

We have found that Hydro Flasks vessels tend to retain some smell after repeated use. Avoid strange-tasting water by designating this as just your coffee thermos.

Do note that the lid system, while reliable and easy to clean, requires two hands to open, while other models we recommend can be engaged with one hand. Small spills will happen if you stumble or fumble while the lid is in the open position — which is not hard to avoid, thanks to a small red square that shows when the lid is properly sealed.

Pros: Good heat retention, sturdy, little stain or scent retention

Cons: Heavy

No US-based thermos company is so instantly recognizable as Stanley, and the brand was among the first to bring double-walled, vacuum-sealed technology to the industry. Stanley's Classic Legendary Bottle holds heat and cold just as well as other top thermoses while staying affordable and nearly as reliable as the higher-tech, modern-day competition.

The larger model has a much heavier-duty handle that inspires as much confidence as the lid latches Stanley is known for, but it might be cumbersome. In any case, it provides a sturdy grip and facilitates safe pouring — which becomes imperative when you're working with two quarts of piping-hot liquid.

Other models we tested didn't have such robust handles, if any. Once thermoses get up to the 1.5-to-2-quart size, a handle becomes appreciated if not required. The smaller model's handle sits more flush, folding almost flat on a series of small hinges. 

Finally, the Stanley Classic Legendary comes in the same 18/8 stainless steel and BPA-free plastic materials that pricier brands like Yeti use, but Stanley's product is priced about $20 cheaper. Plus, by our tests, it's every bit as leakproof.

Pros: 360° lid opens with one finger, touch-enabled LED temperature array and control, personalized monogramming available (at an extra cost)

Cons: No lid lock, charging plate required (not compatible with universal USB chargers)

For the tech-forward person on the move or someone office-bound, the self-heating Ember Travel Mug 2 might be worth the splurge. 

The built-in LED touchscreen controls the temperature of your beverage to the degree between 120 and 145 degrees Fahrenheit (50-62.5 Celsius). There's probably no other way to keep the temperature of your beverage so constant for so long.

Ember also maintains an application that allows you to create presets for your favorite beverages, if you like your latte at one temperature and your Americano at another. While three hours of battery life may not sound like a long time, it also has an "auto-sleep" function, and you can cheat by leaving the battery off at first while your beverage is freshly hot.

And while the thermos itself is not dishwasher-safe, it does withstand one-meter submersion in water, so spillage and wet counters need not be feared.

Pros: Little to no sediment, lightweight, easy to carry, BPA, BPS, and Phthalate-free

Cons: Only holds about 1.5 cups of coffee, doesn't entirely stop brewing

French-press coffee drinkers who like their coffee black might consider Espro's P1 Travel French Press. We have tried half a dozen of these types of models over the years, and this one is the most travel-friendly. 

There are two main drawbacks to this or any other model of travel-friendly French press. First, brewing doesn't entirely stop inside the P1, but thanks to the micro-mesh filters and silicone gasket, it comes pretty close.

Second, due to the plunger running through the lid, heat retention isn't generally as good as with lids that don't have holes running through their center. But four hours of hot coffee is still better than other travel french presses offer.

Cleaning the P1 is much more pleasant than it is with traditional coiled filters. Scrub the filters inside and out, and you're done: no hidden inner workings to harbor bacteria or mold exist. Overall, being leakproof, commuter- and day-bag-friendly, and admirably keeping out grit and mostly preventing over-steeping makes the P1 the most worthy investment in this category.

Coffee thermoses are meant to be used on the go and therefore need to be sturdy and reliable. No one wants to find their coffee cold during a long meeting or open their backpack to a massive spill. A good thermos retains temperature, doesn't leak, and is easy to carry.  

Temperature retention: A thermos should keep iced or hot coffee as close to the original temperature as possible for multiple hours. Double-walled or vacuum-sealed thermoses are the best at retaining temperature but can be heavy. 

Leakproof: Whether you're tossing it in a backpack or riding a crowded bus, your thermos should be well-sealed and virtually leakproof. The lid is often the culprit of leaks; look for a lid that automatically locks when not in use or has a latch instead of a slide that can loosen over time. 

Weight: Since they're meant to be traveled with, coffee thermoses need to be comfortable to carry around by virtue of a lightweight construction or a handy carrying loop. If your thermos doesn't have a loop, consider getting a carabiner clip.

Temperature: We tested temperature retention every two hours (previously, we tested hourly for our guide to best travel mugs) starting at 136 degrees Fahrenheit, the optimal temperature for hot beverages according to this study by the University of Texas. Once temperatures fell below 110 degrees, we stopped testing. Ultimately, the more you open your thermos, the faster it will cool, which will more likely be the determining factor regarding how long your coffee stays hot..

Leaks: We filled each thermos with water and flipped it, shook it, and rolled it around for at least 30 seconds. Any leaky bottles were immediately discounted.

Ease of use and cleaning: Even if a thermos offered great heat retention, if they required heavily involved disassembly and reassembly, and/or weren't dishwasher-safe, we took this into consideration. We don't want to spend our precious time disassembling thermos lids to rid them of bacteria.

Long-term testing: Working parts fail, smells develop, and gaskets get dingy. We are continuing to test our top picks over time to appropriately address any issues we encounter. We'll also be continuing to test other models that we were unable to test during previous rounds.

How do I clean a thermos?

Your thermos may or may not be dishwasher-safe. Warm water, dish soap, and a soft (non-bristled) sponge are best for handwashing, but check the manufacturer's instructions. There may be gaskets or other parts that require removal.

How do I kill bad smells in my thermos?

Water and baking soda will do the trick, but as with warm, soapy water, it's best not to leave it soaking for too long.

What can I put in my thermos?

Dedicate each thermos, mug, or water bottle for one purpose. They can take on the smell and residue of coffee, tainting your water, tea, or wine. Milk can leave a rank smell, and carbonated beverages can destroy the thermos lining.