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The rose gold Ember mug sitting on a desk next to two copies of BBC Science Focus magazine

Ember Mug² review: Is this smart mug worth £99.95?

We tried the smart Ember Mug² to see if it's worth spending just shy of £100 on – after one month of testing, here's the verdict.

Our rating 
3.5 out of 5 star rating 3.5

Our review

For forgetful tea-drinkers like me, it's certainly done the job. But I'm not sure I need my phone to remind me that my cup is half empty (or half full).
Pros: – Keeps beverages at a precise temperature
– Nice to hold and drink from
– Can be personalised to your drinking preferences
Cons: – Not useful if you regularly switch between offices
– Relies on using the charging coaster daily to keep battery high enough
– Doesn't reheat cold liquids, just keeps hot drinks hot
– Not microwave- or dishwasher-friendly

I am used to drinking lukewarm tea. It’s not by choice – I fully intend to finish my cup, but then my work phone rings or I get stuck into a good book. Before I know it, I’ve half a mug of cold builder’s brew left and must decide between microwaving the remains or making an entirely new cup and throwing the old away (which, at the thought of such waste, I can hear my British grandmother gasping).


It’s a minor, albeit daily, annoyance, and one that I could resolve by using an insulated thermos perhaps, or by cutting my caffeine intake. Or, I could spend nearly £100 on a smart mug that promises users beverages at the perfect temperature. But is the Ember Mug² worth it?

Drink to your pleasure

On first use, I was pleasantly surprised by my Ember. I opted for the new metallic design (available for an additional £30) and really do like the look of my rose gold mug and coaster. It’s lighter than I expected, though I should have opted for the larger 414ml (14oz) size, as the smaller 295ml (10oz) option doesn’t quite match up to my ceramic mugs. It’s not a real problem – I’ve just upped my daily dosage to three cups of tea, not two.

The mug comes pre-set to keep beverages at 57.3°C, which was way too hot for my liking, especially for that last drop at the bottom of the mug which felt like it was burning my tongue. But, to change the temperature, you need to use the Ember app, and thus have to have a smartphone. More on the app further down, but it might be useful to know my preferred temperature is 53°C. I only discovered this after playing around for a few days with different options.

One hand holding a rose gold Ember mug next to an issue of Science Focus magazine

It’s important to note that the Ember Mug² is designed to keep things hot, not to reheat drinks that have gone completely cold. You can’t pour in cold coffee from your cafetière and expect the mug to make it drinkable. Nor can you leave your Ember off the coaster, let the battery run down and then expect that putting it back on the coaster will bring your drink up to temp. According to one reviewer, the mug won’t register anything under 37.8°C, but the app won’t let you programme a temperature below 50°C.

For a smart device, it does require some analogue actions. Of course, you can’t microwave the Ember Mug², nor can you put it in the dishwasher. Maybe the next iteration of the Ember Mug could be designed so that the bottom section, which holds the rechargeable battery, could be disconnected?

After about a month of use, I’ve found the mug doesn’t really suit the post-pandemic flexible working set-up that our office has adopted. At home, I can keep the mug on its charging coaster, and if I need to move to another room for a call I can be confident that the battery will keep my drink warm for at least an hour and a half. But when I come to the office, I either need to bring the mug and its charger with me, or purchase a spare coaster for an extra £39.95.

Of course, I could just use a regular mug in the office. But switching from the Ember to a plain old china cup is actually quite difficult. I’m now used to a perfectly-warmed drink at any time of day, so my colleagues now see my unpleasantly surprised grimace when I pick up my mug mid-meeting.

Using the Ember app

The Ember app is available on Android and Apple devices, but due to differences in Bluetooth capabilities Ember say that not all phones will pick up the mug’s signals, so it’s worth checking their list of compatible devices.

Within the app, you can create different presets for all your favourite beverages. If you like your tea precisely 1.5°C warmer than your coffee, well, you’re using the right device for that. You can also link the app with a health app, if you’re particularly concerned about monitoring your caffeine intake. However, having all these different presets can feel a bit like overkill. I don’t want to have to scroll through my phone to make sure I’m logging a flat white, not an espresso, or that this particular drink is caffeine-free. I also can’t access the app without my mug nearby, so I can’t edit settings while out and about (then again, why would I?).

It is fun to see little push notifications asking me ‘What’s in your cup?’ or ‘A software update is available for your mug’. Next thing I know, my toaster will be telling me that it’s the perfect time to pop-up my crumpet and my iron will be reminding me that I haven’t pressed creases into my trousers since 2019.


Ember also make a travel mug than can keep your drinks warm on the go © Ember
Ember also make a travel mug than can keep your drinks warm on the go © Ember

I really like my Ember Mug², but I’m not sure I can quite justify the cost. That being said, I do miss my Ember when it’s out of battery or I’m in the office. Without having tested the first generation, I can’t say whether there is a tangible difference between it and the Mug², nor could I comment on the travel mug that is currently £179.95.

If the mug could work with my coffee machine, or could heat up water, milk and a teabag so that I don’t need to boil the kettle, I’d be more convinced that it’s worth the investment.

But, if you’re going to be drinking three hot drinks a day, every day for the rest of your life, why settle for lukewarm?


If you’re not convinced that the Ember Mug is worth the price tag, check out these options for keeping your drinks warm.

Yurnero beverage warmer


This hot plate keeps mugs, bowls and small plates at temperatures between 40-60℃. It automatically turns off after eight hours, although you can turn it off at any time with a click of a button. It’s powered by mains, like the Ember coaster, and works best with flat-bottomed cups or dinnerware.

Lembeauty USB wood grain coaster


Alternatively, get this attractive-looking coaster and simply plug it into the USB port on your laptop. Amazon reviews are positive, although some say that their mugs have a large footring (thanks to The Great Pottery Throwdown for telling me what those raised bits on the bottom of cups were called) which means the heat actually doesn’t travel enough to warm their drinks.



Or, go it old school with this ThermoCafé from Thermos. It won’t keep your drink hot forever, but it will stay warm longer than in a traditional mug or takeaway cup.

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