October 18, 2020

Review: Ember Mug

Ember mug with coffee
Ember mug with coffee

I was gifted an Ember mug for xmas 2018. For those unfamiliar with it, the Ember mug does one thing, and it does it well: it keeps whatever you put into it at the temperature you specify, for about an hour or longer. Want your coffee kept hot at 145°F (63°C)? It’ll do that. Want your tea kept warm at 125°F (52°C)? It’ll do that too. In fact, it’s so good at doing what it does, that I bought a second mug because the original one was too small1, and I couldn’t live without it.

The Ember mug that I received looks like, and is roughly the same size, as a standard coffee mug. However, it’s heavier and only holds about 10 ounces of liquid because the bottom one-and-a-quarter inches are taken up by the electronics. When you first get your mug you need to pair it with the Ember app on your phone via bluetooth, and from then on, depending on how you use your mug, you may never need to use the app again. The app is used to set the temperature you want your mug to maintain, but if you never change it, you never need to use the app. The mug is smart enough to detect when there is something in it, turns on automatically, and maintains that temperature until it runs out of battery or until it is manually turned off.

Ember mug in charging cradle
Ember mug in charging cradle

The mug needs to be charged and the charging time varies depending on how much the battery was depleted the last time it was used, but in my experience, it takes about 1.5 hours to fully charge it. However, the charging cradle can also be used as a coaster, and if it’s plugged in, it will keep the beverage hot indefinitely. Before COVID, I would keep the mug on the charging cradle near my coffee machine and use the battery to keep my second cup of the morning warm. However, since I’m now working from home a lot, and since I bought a new mug, I’ve set up a charging cradle on my desk and it keeps my second cup of the morning warm until I’m done with it2.

It’s hard to believe that this little mug, with its lack of bells and whistles, can make me so happy each morning. Of course, it’s not perfect, but what product is? The only thing that would improve my experience would be if it could detect the amount of liquid in the mug and reduce the temperature as the amount of liquid reduces. Since detecting the amount of liquid might be difficult, perhaps reducing the temperature based on time would work? I like to keep my coffee at 132°F (56°C) until it’s about half gone, then I reduce the temp to 125°F (52°C). To do this, I have to open the app and select the new temperature, and if I don’t remember to bring it back up to 132°F before turning it off or when starting a new cup, the next time I use it it will maintain the last used temperature of 125°F automatically. But that’s a minor quibble.

When evaluating a product, I like to think about what I would do if it were to be lost…would I immediately go out and get a replacement, would it take some time before I missed it, or would I not really care at al? For the Ember mug, I love it so much that I bought a second one simply because I couldn’t continue living with trying to juggle getting my coffee into it, and it was just easier to get a larger one.

Rating: 9/10


  1. I use a Nespresso Vertuo as my coffee maker, and I pour the milk in before the brew, so the crema gets a little extra “frothy”.
  2. I generally drink the first cup while it’s still quite warm, but the second cup I tend to nurse for a while.