The Ember Mug 2 is a smart coffee mug that uses your smartphone (via Bluetooth) to control beverage temperature. It’s another technological solution to a real-world problem.  With the goal of helping coffee and tea lovers drink on their own time rather than racing against it, the Ember Mug is a hot commodity every holiday season. But for $129, is the smart gadget worth the hype? Also: This $39 water bottle can hack your taste buds: Is it worth it? 


For starters, the Ember Mug 2 doesn’t try to stand out on the design front. It doesn’t have to. The sleek design and saucer-shaped charger remind me of any other coffee set that’s tucked away in your kitchen. I received a matte white version to test, but aside from the more traditional matte colors, Ember also offers a metallic collection for a more modern, sophisticated look.  Aside from the temperature-controlling technology, the one major difference between the Ember Mug and all else is that it’s not dishwasher safe. Instead, the best (and only) way to clean the mug is by gently washing it in the sink with soap and water, and towel-drying.  Also: How to clean your Keurig coffee maker inside and out 

How it works

The Ember Mug 2 can heat up drinks due to the electronic boiler in the base of the mug. And no, the cup doesn’t get too hot to the touch, even if the steam from the fluids within suggests it. So if you’re a fan of using a mug as a natural hand warmer, I’m sorry to disappoint you. The mug comes with a coaster charging station and blinks with an LED light to signal how much battery it has. You can also check the battery on your phone, which is ultimately the mug’s control center.  With the Ember app downloaded, you can adjust the mug’s temperature anywhere from 120°F (50 °C) to 145°F (60 °C). Keep in mind now that this is just a “temperature-controlled” mug, meaning it won’t boil a drink from cold to hot, but simply maintain the heat of what’s already inside. Ideally, you’d start with anything as hot as 170°F, and the smart mug will keep things warm enough to drink throughout.  While the piping hot coffee that I typically get from Starbucks already does a tasteful job of staying warm, I always find the initial minutes too hot to drink, so I don’t mind the Ember Mug’s 145°F limit. 

Battery life and sizing

The Ember Mug 2 comes in two sizes: 10 and 14 ounces. While my tester came in the 10-ounce size, I’d recommend paying more for the larger option, given how effective the drink heater actually is. As advertised, my drinks always stayed warm until the last drop, so I was more inclined to finish them. If you often find yourself drinking less as your coffee or tea cools off, then you won’t have such problems with the Ember Mug.    With a 90-minute battery life for the 10-ounce mug and 80 minutes for the 14-ounce, the mugs are great for slow sippers but certainly not built to last throughout your day without needing a charge here and there. For the most efficient use, I’d recommend trickle-charging the mug between sips using the included coaster.  More: 12 useful smart home gadgets to gift this holiday season

Bottom line

As advertised, the Ember Mug 2 works. It’s reliable, easy to control, and doesn’t feel like a techy eyesore that will render your other kitchen appliances useless. As a slow sipper myself, I’ve definitely reaped the benefits of enjoying hot coffee for longer periods without having to waste another, precious, expensive Nespresso pod or feel the disappointment of a lifeless cup of Joe.  If you’re someone who likes your coffee scorching hot, don’t expect the Ember Mug 2 to keep things sizzling. But if you’re tired of losing the heart-hugging comfort of warmer drinks to Father Time, then this should be at the top of your holiday wish list.