In This Guide
Lukewarm coffee is the only insult I regularly give myself. I get distracted by work and forget my mug until it cools down, only to find my once-beautiful coffee tepid and stale and tragic. The best mug warmers and temperature control mugs offer an elegant and tempting solution: What if my coffee never had a chance to get cold?
But it's a delicate balance between keeping my coffee appropriately warm and roasting the bottom of the cup until the coffee within begins to burn and turn bitter and acidic. Reheating cold coffee makes this bitterness even worse. Only the gentlest of mug warmers will do. I also—no offense to the most tech-forward solutions—don't want to require Wi-Fi and an app to warm my morning Joe. Maybe I also don't want my coffee warmer to be ugly.
Unless you're a terribly specific person, the Ohom Ui 3 Self-Heating Mug ($105) offers the simplest and most pleasant solution. It is a handsome ceramic mug with metal in its base, paired to an induction coffee warmer that could also, if need arises, charge your phone wirelessly. Among budget-conscious options, I like the simplicity of a Cosori Mug Set ($40) that can adjust temperatures to my liking (after only small trial and error).
But if I'm being honest about life, the best way to keep coffee warm is actually a good vacuum-sealed, insulated drinking vessel—which also works while on the go, without batteries. My most common solution is to drop a four-cup batch of coffee into my Fellow Carter Move Mug ($35). My coffee will stay warm for the entire workday and is insulated from oxygen that makes it stale or acrid. Check in on other WIRED-recommended travel mugs here.
Also see WIRED's other coffee coverage, including the Best Drip Coffee Makers, the Best Espresso Machines, the Best AeroPress, Best Cold-Brew Devices, Best Latte and Cappuccino Machines, and Best French Press. Stock up on beans with the Best Coffee Subscriptions.
Best Coffee Mug Warmer: Ohom Ui 3 Mug Set
Almost every self-warming mug set has some problem or another. Most are a little fugly. Many overshoot their target. Some are strangely complicated for a device whose main function is “heating element.” This Ohom mug set, with a warmer and paired mug, manages to do two things simply. It keeps your coffee heated to a pleasant 130 degrees Fahrenheit or above, the ideal temperature at which sweetness and aromatics find their most wonderful equilibrium.
It does so while remaining a pleasant cup to drink from: The Ohom mug is a classic and handsome 12-ounce ceramic mug, with a slight taper toward the top and a thin handle that's comfortable to hold. A lid is included but optional. And unlike some “self-heating mug” designs, you can wash it in the dishwasher or dunk it in the sink. After WIRED reviewer Simon Hill tried out hot plates and smart mugs and travel mugs for years, the Ohom Ui 3 was finally the solution that best mixed ease, functionality, and the little aesthetic niceties that make life pleasant.
The base of the mugset is a little induction hob, which heats up metal in the base of the Ohom mug. When it's not warming your coffee, the base can also wirelessly charge your phone, AirPods, and other Qi-compatible small devices at 15 watts. The pad will heat up a little (but not a lot) when in use. It pulses purple when it's heating a drink, blue when it charges a device. But especially, drinking from the Ohom feels just like drinking from the cup you would have chosen, even if you weren't using a warmer set.
But note you'll have to plug it in: It charges via a USB-C cable that’s about 5 feet long, with a power adapter. The charging base is less pretty than the mug. And there's no temperature adjustment: 130 degrees is my ideal temp, but it might not please people who want their coffee hot enough to inspire an immune system response. Mugs that are less full get a little warmer but never too hot or burnt.
If the Ui3 is too small for you, Ohom also has a heftier Ui+ model ($108) that holds 18 fluid ounces. A backup Ohom mug can be had for $36.
Best Budget Coffee Mug Warmer: Cosori Coffee Warmer and Mug Set
Lord, you can find a shocking number of bargain-basement coffee warmers. This should not surprise you. The base technology is slightly less complicated than your toaster. And yet most of the low-cost heating elements have the same flaw: They get way too hot, burning the bottom of your coffee while still conducting heat slowly up your (probably) thick ceramic mug.
This Cosori solves this problem by using a metallic mug that conducts heat more easily, atop a heating-element base that can be adjusted between 77 and 230 degrees Fahrenheit—accurate to about 5 degrees as measured by my infrared thermometer. For me, the Goldilocks temp setting on this Cosori is 170 degrees Fahrenheit, which keeps a full mug of coffee perennially above 130 degrees. I'm not sure why you'd need to keep any particular liquid at 77 degrees, but this is also possible. You do you.
The mug gets a little hot on its exterior but sports a silicone sleeve for insulation side and (alas) a plastic handle to keep you from burning yourself. But most important, the heat conductivity of metal will keep your coffee warm without subjecting the liquid within to burning hot temps.
The trade-off is, of course, that you're drinking out of a metallic mug, which does feel a little like a camping set. You can use a classic ceramic mug with the base warmer, but you'll then have to turn the heat up to 230 degrees, and your coffee will slowly develop that characteristic diner-coffee burn. I prefer the metal mug, and better-tasting coffee.
Best Thermal Coffee Mug: Fellow Carter
Let's be clear. The actual best solution to keeping your coffee warm and flavorful over a long period of time is probably not a warmer. There's some simple chemistry behind this. Exposing brewed coffee to air, in an open-topped mug, will slowly oxidize it and turn it to cardboard. Exposing coffee to heat—even low heat—will break down some of the acids in coffee into bitter quinic acid, the same stuff that gives tonic water its harsh, bitter tang.
I prefer just not letting the coffee get cold in the first place. Double-walled, vacuum-insulated mug technology has only gotten better over the years. There are plenty of wonderful travel coffee mugs out there that can keep your coffee at ideal drinking temps for literal hours, maybe even the entire workday.
A lot of these travel mugs tend to take the form of a sippy cup. But when sitting at home, my ideal pick is the Fellow Carter, which sips like a normal drinking vessel and is stainless steel—not plastic. It's ceramic-lined on its interior to avoid coffee-oil buildup or any hint of metallic tang. If you like sippy cups, Fellow also offers a nice 3-in-1 lid system ($57) with straw and slider lids.
What I tend to do is drop a four-cup batch of coffee into the Carter, and screw the lid off and on when I take a sip. Sixteen ounces of coffee can stay warm for hours without introducing a lot of oxidation or heat. The coffee in a thermal-insulated drinking container tends to taste better, longer, than any coffee that's been subjected to the heat and air of a coffee warmer.
This said, while the Carter is prettier than most travel mugs, it's never going to be my favorite mug (which, for the record, is a Grinderman tour mug from 2010.) The Carter also doesn't release aromatics quite as well as a more open-topped mug. I could, technically, keep coffee warm in the Carter and then pour it into another mug I am more sentimental about. But in practice, I don't. I just drink out of the Carter. It's still a good morning.
Other Coffee Mug Warmers We Recommend
Ember Mug 2 for $150: Oh, the Ember. It is likely the most sophisticated and technologically advanced of self-warming mugs. It has an app. It'll light up a little LED or even notify your phone when your coffee is ready to drink. Honestly, one can go back and forth on its virtues and excesses. It'll “wake up” when you pour coffee in. It'll go to sleep when you're not around. And unlike other picks here, it's a true self-heating mug with a battery, and it can travel with you on your dog walk. But after using the Ember for years, WIRED reviewer Simon Hill turned instead to the Ohom Ui 3. Why? In part, it's that the Ember only works with a proprietary mug that's not dishwasher-safe or dunk-proof. Replacement mugs and heating elements are expensive. But mostly it was a yen for simplicity: Not everything needs an app, and thermal mugs are now good enough that I sort of prefer them while on the go. Still, the Ember mug has had fervent fans at WIRED, it's a nifty device, and its makers are continually working to improve it. Arguably, the people at Ember are thinking harder about coffee warming than anyone alive, and I'll always happily test the next and the next version to see what's up their sleeve.
Bestinnkits Mug Warmer for $26: This utilitarian little mug warmer turns on when you have a mug atop it, and turns off when you don't. The scale is its only “smart” feature. No Alexa, no Siri, no app. This is a nice feature, and great for safety. This said, it does mean the warmer doesn't start warming till your cup's atop it, vs a warmer like the Cosori or Mr. Coffee that can preheat before your cup is there and thus keep temp immediately. It's a decision, and it's yours to make. The cost difference is somewhat negligible among them all.
Mr. Coffee Mug Warmer for $20: If you plan to just use your own mug, and your mug is a good old-fashioned ceramic mug, this bare-bones, $20 coffee warmer will keep 10 ounces of coffee at 130 degrees Fahrenheit. It'll do this by heating up its element to 230 degrees. This, over time, will make your coffee a little bit burnt and bitter. But it won't be as gross as if it got cold. This Mr. Coffee is unapologetically plasticky and hardly pretty. But this is maybe the lowest-cost warmer on the market that keeps temp well and doesn't have serious flaws. Also note that you will need to remember to shut this thing off, or it'll just stay (very) hot.
Not Recommended
House Gem Mug Warmer for $30: Most warmers either try to be unobtrusive, or are obnoxiously ugly. I give House Gem credit for this wood-grained plastic design that looks pleasingly like an old turntable. There's automatic shutoff after two hours, extendable to 12 hours. So what's the problem? It doesn't just warm, but flat-out scorches your coffee. Even the lowest “130 degree” setting launched well above 300 degrees Fahrenheit. The highest setting went above 400. I like my coffee hot, but I don't want to set it on fire.
How I Test Coffee Warmers
Coffee warmers are a relatively simple technology, and I ask relatively simple things. I want the coffee to be kept in an ideal drinking range, between 130 and 160 degrees Fahrenheit. If a warmer promises a specific temperature range, I use an infrared thermometer to verify that it achieves this. I test how long it takes each warmer to heat up, when relevant. Ideally, this is not longer than it takes to brew the coffee I pour into it.
Especially, I taste continually for signs of burning, acridity, and tonic bitterness that arrive when coffee is overheated and reheated and begins to break down into ugly flavors. It's not just about the surface temperature of the coffee. It's about whether the liquid on the bottom of a mug is overheated, leading to off notes and a worse life.
Otherwise, I also make sure to use each warmer over time, during normal workdays, to see how convenient it is or isn't—and whether it makes my morning better. I tested each mug for at least a full workday. And each of my top picks has been in use with a WIRED reviewer for weeks—or even years, in the case of the Fellow Carter and Ohom Ui 3.
.png){kind=logo}
