Ember Mugs are designed to keep your coffee or tea at the perfect drinking temperature for hours at a time. But can they heat up cold water or do they just keep drinks warm? What about boiling water or cooling down drinks?
Whether you've just bought yourself an Ember Mug or you're considering it and have some questions in this article I'm going to answer some of the most common questions around the Ember's ability to heat or cool drinks and it's ability to keep drinks hot.
Will Ember Heat Up Cold Coffee/Tea?
Sometimes you've got cold coffee in the fridge and you want to warm it up to drinking temperature. Can you use your Ember to heat up cold coffee or cold tea?
You CANNOT use Ember to heat up cold coffee, tea or other drinks. The cup won't recognise liquid under 100ºF (38ºC) and won't turn on. Plus even if it did it takes AGES (30-60+ minutes) to warm up cold drinks and will drain all of the battery life of your Ember. It's designed to keep drinks hot, not make them hot.
You can use the Ember to heat up lukewarm or room temperature water but it may require manually adjusting the temperature using the app in order to get the mug to start working to warm up your beverage, and again it'll take a LONG time and use all the battery if it's not plugged in.
In my opinion this is one of the big limitations of the Ember cup and it would be good if in future generations they gave you this ability.
Even pouring in a drink that is 120ºF takes 20 minutes or so to heat up to 140ºF and uses the majority of the battery life in order to do so.
If you're looking for a travel mug that can heat up cold beverages and make them hot then check out my Ember Mug vs Cauldryn comparison. On there you'll find the Cauldryn which can heat up cold water and actually even boil water.
It also comes in at cheaper than the Ember, it's just not quite as sexy but definitely worth a look.
Can Ember Keep Drinks Cold?
The Ember is battery powered and able to keep drinks hot but can the Ember Mug keep drinks cold too?
No, the Ember Mug does NOT keep drinks cold. It only has a heating element to keep drinks warm and the insulation isn't that great so it won't keep drinks cold for a long period of time.
If you want to keep drinks cold then you'll want to get a vacuum insulated tumbler cup or a water bottle. I did a list of the best tumbler cups for ice retention where you can see which ones perform best or if you specifically want one like the Ember that doesn't leak then check out my list of the best leak proof tumblers.
There was a brand called YeCup that tried to release a battery powered mug that had the option to either keep drinks cold or make them hot.
Unfortunately the cooling element worked extremely poorly and it took around 3 hours just to lower the temperature of your drink by a few degrees.
I think they ended up giving up on the idea because they then release the YeCup H which only does heating. You can read more about it on my list of the best battery heated coffee mugs.
Does Ember Mug Heat While Charging?
If your Ember is running out of battery and you place it on it's charger will it continue to heat your drink while it's charging?
Yes, the Ember Mug will continue to heat drinks while charging. As long as the battery is below the regulated max temperature it'll both charge and heat your drink at the same time. Charging will be slower than if you were charging it whilst it was of.
It'll charge slower because power is being used to keep your drink hot, but it'll still continue to charge and eventually be fully charged and ready to take on the go again.
It's important to note that the Ember has a 2 hour shut off. If it's filled with drink and sitting on it's charging dock for 2 hours without being touched it'll go into sleep mode and will stop heating but will continue to charge.
To keep it awake you need to pick up your Ember Mug or tap it, you can also pick it up to wake it if it's gone into sleep mode.
Can You Boil Water With Ember Mug?
How hot can the Ember Mug make drinks and can you boil water with the Ember Mug?
Unfortunately you can NOT boil water with the Ember Mug. It's max heating temperature is 145ºF (63ºC) and it doesn't go any higher than that. It's also only really designed to keep drinks hot, not to heat them up to boiling temperature.
If you're looking for a mug that IS able to heat drinks up to boiling temperature of 212ºF (100ºC) then you'll want to check out the Cauldryn Heated Travel Mug.
It's cheaper than the Ember Mug but can heat drinks all the way up to boiling temperature. It also has a longer battery life so well worth a look.
How Hot Can Ember Mug Heat Drinks To?
If you're one of those people who like to drink their tea or coffee as hot as physically possible you might want to know how hot can the Ember Mug heat drinks to.
The Ember Mug can heat drinks to a maximum of 145ºF (63ºC) and won't go any higher than this. Keeping it at this highest setting will drain battery life faster than the recommended 135ºF (57ºC).
The lowest temperature Ember Mug can be set at to keep drinks warm is 120ºF (50ºC). If you want your drink to be colder than this then you'll need to turn off the power to your mug and let your drink cool down naturally.
Does Ember Mug Heat Water?
Ember Mug is designed for coffee but can it heat water too?
Ember Mug is designed to keep drinks hot and that includes water. It can heat water but it takes a long time and drains a lot of battery. Extremely cold water won't work in the Ember Mug.
This is because the Ember Mug will only recognise liquid above 100ºF (38ºC) and if it's below this temperature it won't turn on.
It's designed to keep hot drinks warm not to warm up cold drinks.
Can You Put The Ember In The Microwave To Heat Drinks?
If your Ember has shut off or your drink has cooled down too much can you quickly throw it in the microwave in order to quickly heat the liquid and help the Ember out?
No, you should NOT put the Ember Mug in the microwave. The metal and small electronics build up electrical charge and can spark and permanently ruin your Ember Mug.
Because it has a battery in it that can potentially catch on fire this makes it even more dangerous.
In my experiment on alfoil in the microwave I did find that smaller pieces of metal do spark and the Ember Mug has a bunch of small computer components that are close to each other and designed to run electricity.
This is the perfect storm for a microwave and can easily damage the computer, battery or heating element in your Ember and make it stop working.
So don't put your Ember in the microwave or you'll end up with a $100+ mug that isn't smart at all.
Will Ember Mug Auto Shut Off When Not In Use?
The Ember Mug is designed to keep drinks warm for hours at a time, but does it auto shut off when not in use?
Yes, the Ember Mug will auto shut off after 2 hours if it is not picked up or tapped. It will shut off even if it has liquid in it. This prevents that battery overheating and saves power. It also auto shuts off when it is empty.
If you want to keep your Ember working then all you have to do is pick it up or give it a tap and it will detect the motion and stay on for another 2 hours.
It's good that it auto shuts off because otherwise you could accidentally leave your cup of coffee at work or at home and go out and if it was on for too long the battery or components could overheated and break your Ember.
When charging the Ember Mug the charger will automatically switch off when the battery is completely full so no battery damage will occur.
More Ember FAQs
If you want to learn more about the Ember Mug then you can keep reading below: