The Best Travel Mug
The new Zojirushi Stainless Mug offers the best balance of heat retention and versatility. It’s very much an evolutionary improvement over its predecessor, which was our previous pick for the best travel mug, but in this case that’s all that’s needed. The new version is lighter and has a more svelte lid design. It’s more pleasurable to drink from, but retains similarly astounding insulating abilities. After a full 8 hours, coffee kept in the new Zojirushi Stainless Mug was nearly as hot as the coffee in the old version of the hardware and 20 degrees hotter than it was in the next mug down in our test group—just enough to make the difference between drinkable and lukewarm.
And let’s not forget that these things need cleaning every once in a while. That’s why we also have a bottle brush recommendation down below for when you need to clean the gunk out from time to time.
Table of contents
- Should you upgrade?
- How we picked
- Our pick
- Who else likes it?
- Flaws but not dealbreakers
- Long-term test notes
- Better for cupholders
- Care and maintenance
- What about cold drinks?
- Wrapping it up
Who’s this for, and should you upgrade?
The type of person who would buy one of these things is one who likes to make their own hot drink at home to take with them throughout the day—perhaps because of stingy office mates, or perhaps because of the horrible-quality coffee and tea out in the world. You usually want the coffee to stay hot at least through the duration of your commute, if not for several hours after you arrive at the office. You want the mug to be easy to use in the car or at your desk and so leakproof that you can toss it into your bag or briefcase without worrying about ruining your gadgets.
If you’re a big coffee nerd and don’t mind proclaiming it, this could be the factor that makes you decide against a travel mug.
We talked to 2012 U.S. Barista Champion Katie Carguilo and The Awl’s editor in chief (and the author of our coffee gear guide) Matt Buchanan. Both agreed that the true best way to enjoy a high-quality cup of coffee is to drink it out of an open-air container within 15-20 minutes of its being brewed. This is because the flavor of good coffee begins to degrade the minute it’s brewed, so the still-piping-hot coffee from your travel mug will taste different 6 hours later than it would if it were freshly brewed. If you care to know more about how travel mugs affect taste, read Footnote 1, but we won’t bore tea drinkers with the details.1
But we realize most average buyers just want a decent cup—probably something better than whatever your office buys from the local Save-a-Lot or whatever you can pick up on the road from Starbucks. In that case, you’ll likely be brewing your own at home using whatever coffee you like best and pouring it into a travel mug to be taken with you. That’s the target audience for this guide.
How we picked
Travel mugs tend to come in three basic materials: plastic, glass/ceramic, or stainless steel. According to previous tests performed by Cook’s Illustrated, all-plastic mugs can’t retain heat for more than an hour and all-ceramic for no more than 30 minutes. Good Housekeeping agreed, stating that plastic and ceramic mugs don’t retain heat for long and break easily.
That wasn’t acceptable to them or us, so all-plastic and all-glass mugs were out. Indeed, when you look at various other guides that have been written on the subject, including an extensive heat retention test performed by Tested, the ones that rise to the top are always stainless steel—double-walled, vacuum-insulated stainless steel.
Occasionally, travel mugs come with a stainless steel exterior and a ceramic or glass interior. This option tends to be better for those with sharp palates—people who can taste (and care about) a change in flavor when drinking coffee directly out of a stainless steel container.
As such, it would seem easy to assume that coffee experts would never use or recommend a container with an unlined stainless steel lining, but that would be wrong. The problem with glass or ceramic interiors is that they can still break easily—one wrong drop or bump and your minor investment is in bits on the floor.
This was a common problem among the ones we researched in this category, and few people are happy after spending money on something that breaks. Besides, a growing number of stainless-steel-lined mugs (including our pick) now come with electro-polished interiors, which makes the steel less likely to hold on to strange odors and flavors. That’s why our experts recommended sticking with stainless steel for its durability and insulating capabilities—and if you feel you can taste a metallic flavor, try pouring the coffee out into an open-air mug before drinking it.
Regardless of palate sophistication (or lack thereof), our experts and research agreed that a vacuum-sealed travel mug made entirely out of stainless steel (save for the lid) was the best choice for most uses. It retains heat the best out of all the available materials and is the least breakable, which is a double win.
Despite limiting our focus to all-stainless models, there were still hundreds of options to consider. So, we turned to a number of publications to see what they liked the best and which criteria they used. The three best guides on the subject are the previously mentioned ones by Tested and Cook’s Illustrated, plus another one from Good Housekeeping, which all took a slightly different angle to evaluating travel mugs. We also considered the most highly rated ones from Amazon. From there, we focused on models that were highly ranked for heat retention and ease of use, taking extra care to select ones that would be easier to clean as well.
In the end, we were faced with six travel mugs to test ourselves: the Zojirushi Stainless Mug, Zojirushi Tuff Mug, Thermos Nissan Backpack Bottle, Thermos Vacuum Insulated Travel Mug, Contigo Autoseal West Loop, and the OXO GoodGrips LiquiSeal Travel Mug. Then we took the updated version of the Zojirushi Stainless Mug for a spin as well.
How we tested
According to Carguilo, and supported by the findings at Cook’s Illustrated, coffee (and black tea) is typically brewed at about 200°F and the best temperature to drink is at roughly 145-155°F. There’s some debate over the technical ideal when it comes to the temperature for coffee drinking, but we used Carguilo’s guidance to perform our tests. Subjectively, when it came to drinking temperature, 155°F came off as a little too hot for our liking (but was still drinkable), while coffee seemed quite pleasantly hot down to about 140°F. Anything below that started to feel lukewarm.
Our tests themselves were very similar to those performed by Tested: I poured freshly brewed coffee into each of the mugs and measured their temperature using a candy thermometer. Then I measured the temperature in each of the bottles every hour for 8 hours.
To measure leaks, I poured hot, green water (thanks food coloring!) into each of the mugs and set them on their sides in a messenger bag overnight, and I performed the same tests again while setting them completely upside-down on a white towel overnight. None of the mugs leaked by any discernible amount.
I also dropped them all several times with no major explosions or breaks, though stainless steel has a tendency to dent if you drop it too much over time.
Another important criterion that’s not easy to measure objectively is one-handed ease of use. If you’re going to be using it while driving or biking (not that we recommend it), you’ll definitely need at least one hand free and probably both eyes. A good mug should be easy to both open and close, as well as lock and unlock, with one hand without having to look down at it.
The locking mechanism is another crucial part of the mug because if you’re carrying it in the same bag as your computer, the last thing you want is for it to spill everywhere when you hit a pothole or bump in the road. Not all the models we tested had this function, but among the ones that did, some were definitely better designed than others.
As far as cleaning goes, none of the mugs we tested were recommended for dishwasher use because dishwashers introduce heat and water pressure to the vacuum seal, which can degrade the bottle’s ability to retain heat over time. Really it’s a question of which mug is easiest to clean by hand; bodies are not a huge problem, but the ability to disassemble the lid matters.
Like the original Stainless Mug (our previous pick), the new version has sturdy leakproof seals and a simple locking mechanism that I can trust if I want to throw it into a bag, and it’s easy to use one-handed. It didn’t leak, it didn’t spill, it’s pretty tough, it can take a bit of a beating, and it has an attractive design that’s minimalist, yet eye-catching in its simplicity. While the new mug hasn’t been available for long enough to accrue a significant amount of user or professional reviews, the old version had the best overall Amazon reviews of any travel mug out there and came recommended by several trustworthy publications.
In the 2013 version of this guide, among the six mugs/bottles that met our testing criteria, the original Zojirushi Stainless Mug won the number one spot by a landslide when it came to retaining heat: The temperature of the boiled water we poured into it only dropped by about 37°F over a period of 8 hours, which was a full 26°F better than the second place Thermos mug.
While the older version of the Stainless Mug provided marginally better heat retention than the new version, it weighs 1.6 ounces more (about the weight of two AA batteries). While this might not sound like much, ounces add up to pounds, and for someone commuting with their travel mug in a bag along with their laptop, lunch, and perhaps a change of clothes for the gym, heft matters. After consulting with a number of our editorial staff on the issue, we decided that the new Zojirushi Stainless Mug’s lighter weight was worth trading off a few degrees of heat retention for.
Unlike most of the competition (save for the Thermos Nissan), the Stainless Mug also has a secondary locking mechanism that allows you to keep the seals extra secure when needed. But the secondary lock isn’t necessary if you’re actively drinking from it; it’s easy to feel for the button and pop it open, take a sip, and pop it closed to put back into a cup holder.
The sliding lock (the secondary locking mechanism) is meant to prevent accidents from happening should you throw it in a bag with your gadgets. Just flip a switch and you’re guaranteed that there’s no way it will pop open when you don’t want it to. I would feel very comfortable putting it into a bag and letting it roll around on its side or upside down without any consequences. The Thermos Nissan has a similar mechanism, but it requires you to manually click a metal loop onto the latch. While it isn’t “difficult,” it isn’t as convenient as just flipping a switch on the Zojirushi.
It’s also durable. It did show a few scuffs when doing drop tests, but not any worse than the other options. None of them broke, though, so it’s really a six-way tie in terms of durability. Oh, and if you do happen to drop it, the Zojirushi Stainless Mug’s vacuum insulation is protected by a five-year limited warranty.
Unlike most of the other companies that we looked at, Zojirushi offers their travel mugs in a number of sizes. In addition to the 12 oz. and 16 oz. sizes that the last generation version of the Stainless Mug was available in, the new iteration of the hardware can also be had in a 20 oz. capacity. That’s enough for it to pull double duty as a day-to-day water bottle as well.
After the latest update to this guide was published we were contacted by a reader who was concerned about the fact that the latest iteration of the Zojirushi Stainless Mug uses a non-stick flourine (which amounts to fluoropolymers of the sort used in Teflon coating to help repel stains and odors from the interior of the mug. This is contradictory to what we were told by Zojirushi’s PR on several occasions while researching the guide.
A lot has been written about the potential dangers of eating or drinking from vessels containing non-stick coatings. Some outlets, like Cancer.org feel that as they have the potential to leech chemicals, those who use them could suffer long-term health problems (a stance supported unofficially by the EPA.) Others look to the fact that so long as a non-stick coating like Teflon is not overheated (the chemical bonds in Teflon start breaking down between 400 and 500 degrees Fahrenheit ) it’s a safe technology to use, provided you use it properly.
If you believe the latter is the case, like we do, then the SM-SA48 Stainless Mug is for you. If drinking from a mug with a non-stick coating makes you uncomfortable, then consider going with our runner-up, the Zojirushi SM-KHE48AG Stainless Mug. While it’s heavier and less compact than our main pick, it proved to be a slightly better insulator, and doesn’t come with a non-stick coating.
Who else likes it?
An older version of the Zojirushi Stainless Mug was Tested’s choice for Best Thermal Mug, and Smith told us he continues to use a newer version of the mug today. In Tested’s tests, the Zojirushi didn’t retain heat quite as well as heavier-duty bottles that come with separate cup tops, but those are generally bulkier and require you to keep track of more parts—not quite so good for the everyday commuter.
Good Housekeeping also named the Zojirushi an “outstanding performer at keeping drinks hot or cold,” and said it was easy to open and that it won’t obscure your line of sight when drinking.
When it comes to Amazon reviews, it’s pretty hard to argue against the Zojirushi Stainless Mug. At the time this was written, the previous version of the mug had earned a 4.5 average from a total of 1,077 reviews. Of those 1,077 reviewers, 915 had awarded the mug a five-star rating. More than this, the hardware had only earned 23 one-star reviews as of this writing, two of those concerning the fact that the bottles are made in Thailand.
It’s hard to find one single review that encapsulates the overall feeling about this mug, but this one is pretty close: “[A]fter making some very hot tea that I planned to take with me the next day, I filled up my [mug], sealed it, and placed it in the fridge for over twelve hours. Got up the next morning, took my shower, went to have a small sip of my delicious tea and damn near burned my tongue. You just can’t beat that!” While the new version of the mug hasn’t been around for long enough to produce as many reviews (there were only two for it on Amazon at the time this piece was written), we feel safe, based on the stellar editorial and user reviews the last two generations of Zojirushi Stainless Mug has received, in recommending it to you.
Flaws but not dealbreakers
Our only major complaint about the Zojirushi is that it’s actually a bit too good at insulating sometimes. I find that if I make a very fresh pot of coffee and pour it directly into the travel mug, it ends up staying mouth-burningly hot for hours. I’ve learned to let it cool a little before closing the lid—a piece of advice echoed among many other Zojirushi owners. Alternatively, you could add an ice cube before heading out the door.
Another small complaint is that it’s a bit skinnier than your typical travel mug, which means it doesn’t fit super snugly into cupholders or bike water bottle cages. But if that’s a priority, we have an alternative pick below.
On a similar note, the Stainless Mug has a notably narrow opening for liquid to come out of. This is good for preventing burns from potentially scalding coffee or tea, but makes it less than ideal for use as a day-to-day water bottle or for people who like to really gulp down beverages. You could always take the lid off entirely, but that kind of defeats the whole purpose of the mug’s ease of one-handed use.
Finally, at more than $30, the Zojirushi is on the higher end of the price range, but it’s worth the handful of extra dollars over the competition because of the container’s superior construction and performance. After all, the entire point of a travel mug/bottle is to keep your drinks hot and not spill them everywhere, so it’s worth the extra cost to make sure you’re carrying a high-quality product.
Long-term test notes
After consistent use for almost a year, our previous pick still retains heat just as well as the day we got it. Although not advisable for double-walled stainless steel (see our “Care and maintenance” section below), it has survived several accidental trips through the dishwasher without any noticeable decrease in performance. It has traveled around in many bags and purses along with other gadgets without leaks.
Better for cupholders
That’s why, if you’re someone who spends a good amount of time in your car and you like to drink your freshly brewed coffee while driving to work, something like the stainless steel OXO Good Grips LiquiSeal Travel Mug is a better choice. This $20 mug is more geared toward the person who is actively drinking from the container, meaning it’s designed to fit your hand and your car’s cup holder a little better.
The OXO doesn’t retain heat nearly as well as much of its competition—somewhere between 1 and 2 hours after brewing coffee at 200°F, the liquid temperature falls into lukewarm state, so you’ll definitely want to drink it within the first 1.5 hours after pouring.
Care and maintenance
As mentioned earlier, none of the mugs we tested were recommended for dishwasher use. Dishwashers introduce heat and water pressure to the vacuum seal, which can potentially degrade the bottle’s ability to retain heat over time. So it’s a question of which mug is easiest to clean by hand.
It comes with a large bottle brush, a skinny straw brush, and a looped detail cleaning brush, all kept together by a handy ring so you won’t lose any of the parts. The set is dishwasher safe, and after 96 separate reviews it doesn’t have a single one-star review on Amazon, so it’s a pretty good bet for anyone looking to get gunk out of their hard-to-clean items. We bought a couple sets to confirm their quality and they are as good as we thought they would be.
The competition offers similar products for a similar price point—the OXO set is $12.99—but there are downfalls. A $9.99 set from Contigo generally serves the same purpose, but some users think the bristles are too soft and that the entire set is difficult to store, especially since it isn’t held together by anything. There is another bottle brush kit for just more than $14 from Camelback, but it doesn’t come with a detail brush and users generally feel the quality isn’t as high as the brushes from OXO.
What about cold drinks?
Although we didn’t place much emphasis on keeping cold liquids cold—check out our water bottle review for what’s best for that—we did find that the Zojirushi Stainless Mug retained cold better than all six of the other mugs in our lineup.
Over a period of 8 hours, it only allowed our icy cold 33°F water to rise by four degrees, while the others in our lineup allowed the temperature to rise considerably more during that time. So if you’re looking for a dual-use container that can preserve both hot and cold well, the Zojirushi Stainless Mug can hold its own—especially now that it’s available in a larger 20-oz. capacity. Just be aware that its aforementioned narrow opening is less than ideal when you’re trying to quench an undying thirst after cresting a tall hill while hiking.
As we mentioned earlier, there’s plenty of competition out there—it’s all over the map and extremely similar at the same time. And truth be told, most will do a halfway decent job of keeping your coffee warm. Like smartphones making phone calls, insulated travel mugs can (mostly) perform their basic function, but the devil is always in the details.
We also considered the Zojirushi Tuff Mug, which is very similar to the Zojirushi Stainless Mug in its design and functionality. The Tuff Mug performed exceptionally well in our heat retention tests (it was basically tied with the last generation Stainless Mug) but got the boot because of usability issues. The Tuff Mug mysteriously has a completely removable top lid and a difficult-to-understand drinking mechanism; we gave it to several very technical friends to mess with and no one could figure out how to make the liquid come out upon first blush. Separate parts mean more things to lose when you’re out and about, and confusing usage means murder for someone trying to keep their eyes on the road. You also can’t completely disassemble the top, meaning it might harbor smells or gunk later on.
The container that was the most like the Zojirushi Stainless Mug was the Thermos Nissan Stainless Steel Backpack Bottle. The design is almost exactly the same: a double-walled, stainless steel bottle with a screw-on top that has a button you can push to pop it open and a separate locking mechanism for throwing into a bag. It did a pretty good job of keeping our coffee hot, too—it came in third place after the three Zojirushis and was the only other bottle in our lineup that kept coffee at barely-above lukewarm temperature after 8 hours. The main reason it lost out to the Zojirushi is that the secondary locking mechanism, which is just a metal loop that fits over the front of the lid, can be finicky for those who have ham hands (such as myself) or anyone who might be fiddling with it while driving. Plus, the Nissan is only about $5 less than our top pick, so why go with second best?
We also tested a Thermos Vacuum Insulated Travel Mug (with tea hook), arguably the only container we tested that is actually shaped like a traditional mug. While we liked the look of it, the heat retention was just so-so—it was only able to keep coffee at or above optimal drinking temperature for about 4 hours—and we found the tea hook to be unnecessary. (There are people who use these containers for tea, and most of the time, they just plop the tea bag into the bottle without any problem.) The Thermos Mug has a push-button interface just like the OXO discussed above: There’s a button on the top that you press in when you want to drink and press again to seal it back up again. Again, it can be confusing to determine whether the button is in the up or down position just by looking at it, meaning you may find yourself pressing it over and over again to figure out whether it’s open or closed. When there are better options out there, no thanks.
And finally, we tested the 16-oz. version of the Contigo Autoseal West Loop. Like the OXO, the Contigo is clearly designed more as an active drinking vessel than something you’ll throw in a bag to drink later at work. It’s wider, so it fits more securely in a cup holder, and it has a one-button interface so you can easily take a sip without having to look at it. The downside here was that it had about the same level of heat retention as the OXO (which is to say not very much). The Contigo was only able to keep our coffee above lukewarm for between 1 and 2 hours, which might be fine if you make your coffee at home and drink it while driving to work, but it’s not particularly versatile for other situations. In this case, we just happened to like the OXO’s drinking button better than the Contigo’s, though in reality, the two could almost be used interchangeably.
There were several others that we considered but didn’t place into our final tests. For example, there’s the Contigo Extreme Mug, which Good Housekeeping says can obscure your view when drinking—bad for drivers—and can be uncomfortable to sip from.
Bodum also makes a combination French press and travel mug that sounds appealing because you can literally brew your coffee inside the mug as you take it with you. In reality, though, it’s not much different from brewing the coffee first and pouring it into the mug (in fact, it might be worse because the Bodum will keep your coffee grounds in contact with the hot water for much longer, therefore changing the flavor and making it more acidic). Additionally, as those familiar with French presses know, it could leave you with coffee ground bits floating around in your coffee.
We got some requests to look at the Hydroflask, so we did. It’s not as good as the other options, let alone our pick. It only maintains heat at a drinkable level for a handful of hours (4 or less) and the drinking lid can’t be locked so it’s at risk of flipping open, potentially spilling everywhere. I would definitely not risk putting it in my bag, and I would be very careful about even dropping it or knocking it over.
Wrapping it up
If you want a reliable travel mug/bottle that you can either drink from directly or pour into a separate mug, the Zojirushi Stainless Mug is the top of the tops. It retains heat for an obscenely long time, allowing you to brew your favorite coffee at home and take it with you to work, school, or on road trips without having to reheat it all day. And it definitely won’t leak in your bag and ruin your gadgets.
Travel Mugs, Cook's Illustrated, October 1, 2011
Thermal Coffee Mugs Tested, Good Housekeeping,
Tested: Six Insulated Bottles to Keep Your Coffee Hot, Tested, June 7, 2011,
Our Favorite Tech of 2011: Zojirushi 17-oz Thermal Mug, Tested, December 28, 2011,
The Best Thermal Coffee Mugs, Good Housekeeping
Originally published: August 4, 2014