Is a $180 smart mug really worth the price? We put the Ember Mug 2 to the test

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I hardly ever go a day without coffee. Yes, it helps me wake up in the morning, but I also really like the taste of a good brew and enjoy sipping a cup while I work. Therein lies my problem: I drink quietly and often take a cup to be disgusted by the bland, lukewarm liquid that awaits me.

So when I heard about Ember, a self-heating mug that promises to keep your drink exactly as hot as you want it, I knew it might be the answer to my (admittedly very minor) problem. I recently tested a 10-ounce Ember Mug 2 from the Metallic Collection ($180,, and this is what I found.

It’s easy to use. Ember mugs are Bluetooth enabled, so you can connect to an app on your phone and set your ideal temperature between 50°C and 62.5°C. But even if you don’t have a smartphone, you can still use the cup. Out of the box, it’s set to 57°C (considered an ideal average), so it’s ready to go after an initial charge, which takes around two hours. It’s also perfectly safe to wash by hand, and an indicator light lets you know when the cup is working or needs another charge.

The technology is impressive. The Ember Mug 2 is equipped with four precision sensors that can detect when coffee or tea is poured into it and regulate the temperature, while a built-in battery and heating system provide the actual heat – and they do. I drank a single cup for almost three and a half hours, and my coffee stayed perfectly hot and fresh tasting the entire time.

I don’t like my drinks to be very hot and I found the default temperature of 57C to be a little too high, so I lowered the temperature a few degrees. After a few minutes the app alerted me that the desired setting had been reached and I could feel the (more palatable) difference when I took a sip.

The battery lasts 90 minutes, which means you can leave your desk for a quick meeting, cup in hand, without worrying about losing heat. When you’re not on the go, you can simply place the cup on the coaster-shaped charging disc.

Sensors can be, well, sensitive. The first time I used the mug I made a latte and had no issues. The next day I made a cup of regular coffee and added a splash of cream. But after putting it aside, I realized the light was off, which meant my drink wasn’t being kept warm.

Confused, I turned to the Ember site and found a few possible reasons: pouring liquids colder than the set temperature can lead to false detection, and adding honey can block the heater if it sinks to the bottom. In my case, those weren’t the issues.

But pouring in cold cream or milk can cause a drink’s temperature to drop too quickly, fooling the sensors, so it’s best to slowly stir in any cold liquid. I also found that the temperature setting on the app turned it on and my coffee was hot again in no time.

It’s a nice splurge to have. The original mugs and metal collection are sleekly designed, and the Mug 2 charging coaster has been streamlined to be smaller and more attractive. Yes, that’s a lot of money for a cup (the the masts go for a little less, $150), but it’s rare for something this technical to work exactly as advertised. Definitely worth considering if you are ok with the expense. For a slow drinker like me, I don’t know how I’ve been able to work from home for so long without it.


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Eleanor C. William