Ammunition Designs Ember, The Perfect Travel Mug

It won’t just keep your coffee hot for hours. It’ll cool it down to the perfect temperature, then keep it there.

All travel mugs are pretty much the same. You dump some tea and coffee in it, you slap the cover on, and it slows down the process through which your hot drink becomes room temperature. Ember is different. It’s an intelligent, high-tech travel mug, immaculately designed by Ammunition, which not only keeps your drink at a specific temperature for hours, but will even actively cool your scalding coffee down to a more drinkable temperature.


A smart, Bluetooth-connected travel mug sounds like parody—the Internet of Things gone mad. But if you saw the Ember in someone’s hands, you’d never know. The Ember looks a little sleeker and more sophisticated than an ordinary travel mug, true, but it’s most definitely of the same species. Yet unlike a regular travel mug, the Ember contains insulated walls filled with a proprietary phase-shifted material, which allows the mug to both warm and cool liquid precisely. It also pairs with a smartphone app over Bluetooth, allowing you to quickly dial in preset temperatures: brewed coffee at 140˚F, lattes at 134˚F, green tea at 148˚F, and so on.

The most critical aspect of the Ember’s design, though, was that all of these high aspects are hidden away. Though the Ember contains a built-in screen which shows the temperature of your drink, this display seamlessly blends in with the surface of the mug, so that it’s invisible when off. Nor does the Ember have any buttons: to adjust your drink’s temperature, you just thumb the secretly capacitive Ember logo and twist a dial on the bottom of the mug. Even charging the Ember seems analog: you just rest it on a special coaster at your desk when you need to recharge the internal battery.

Keeping all of this sophisticated technology stealthy in the final design was integral, says Clayton Alexander, the founder of Ember. “I wanted it to have a very human interface,” he tells me. “My earliest prototypes had a lot of buttons, switches, and screens, but I knew that if wanted it to be adapted by the masses, we’d have to do what Apple does: take that great technology and cover it in a beautiful, human design. That’s why we went to Ammunition.”

“The idea that every object in our life should be a richly featured piece of computing is absurd,” agrees Ammunition partner Matt Rolandson. “We’re all for designing a mug and adding technology to that, but only to augment what people expect. Mugs, cups, glasses: these sorts of objects don’t have buttons, and we don’t think they should. They should feel familiar, meet consumers where they already are, then help lead them somewhere new. That’s our prime principle: we want to help design everyday things, without messing up everyday things.”

But even without all of its secret technology, it was important for the Ember to just be a great mug. One design innovation Ammunition is particularly pleased with is the Ember’s cover. Most travel mugs have covers, but they suck. They are usually small little slits you have to twist open, and which press up against your nose while you’re drinking. Ammunition’s industrial designer Martin Gschwandtl says that it was important for the Ember’s cover to be designed so that it has the mouthfeel of drinking out of your favorite ceramic mug. So instead of twisting the cover on the Ember, you push down on a vacuum seal button in the middle of a deep well. Not only does this design have the perk of being easier to open and close than your standard twist cover, but it feels like a normal mug, with no nose touch.

Now available for preorder starting at $109, Alexander says temperature adjustable mugs are just the beginning for Ember. “Ember is a platform,” he tells me. “Anything in your kitchen you can imagine benefiting from being temperature adjustable? We want to do.” Today, Ember might be keeping your coffee warm: tomorrow, it might be in your soup bowl or dinner plate.