Just like you I love my coffee and I hate it when my coffee gets cold before I get to finish drinking it. There are many different types of ceramic mugs to choose from but I heard stoneware mugs could keep coffee hot for longer.
But do stoneware mugs keep coffee hot?
I couldn't find a good answer online so I decided to look into it myself. The results were pretty interesting:
Stoneware mugs tend to keep coffee hot longer than porcelain and china mugs. Not because the material itself is more insulating but rather because stoneware is thicker than porcelain. It is the thickness that keeps the coffee hot longer.
What Is Stoneware and Why Does It Keep Coffee Hot?
Stoneware is a dense type of ceramic that is heated at high temperatures above 1,200ºC.
It's non-porous, dishwasher and microwave safe and gets its name from its stone like qualities. It comes in a variety of different clay colors and designs.
The main differences between stoneware and porcelain ceramics are their color, thickness and temperature the clay is fired at.
Stoneware is generally thicker than porcelain and china and is fired at lower temperatures. Porcelain can be more easily molded with finer details.
Both are non-porous and work great for coffee as they won't impart flavors.
How well something keeps heat is based on it's thermal conductivity and it's thickness. The thicker something is the harder it will be for heat to transfer through it.
Because stoneware is generally a fair bit thicker than other ceramics the heat of your coffee finds it harder to escape thus stays inside the cup for longer.
The thinner the ceramic the faster your coffee will lose temperature.
So of the different types of ceramic coffee cups stoneware is the best at keeping your coffee hot.
How To Keep Coffee Hot In a Stoneware Mug For Longer
If you're like me and want to keep your coffee at that perfect drinking temperature for longer there are a few things you can easily do to extend the lifespan of your hot coffee.
1. Pre-Heat Your Mug
At room temperature your stoneware mug is COLD compared to your coffee. When you pour your coffee into a cold cup the heat instantly transfers from the coffee to the cup which cools down your coffee.
As stoneware is thicker than porcelain a cold stoneware mug will steal more heat from your coffee than a cold porcelain mug.
A solution to this is to fill up your stoneware mug with boiling water and leave for anywhere from 15-60 seconds to completely heat up your mug.
Then discard the boiling water and pour in your coffee. As the cup is already hot (likely hotter than the coffee itself) it will not steal heat from your coffee and your coffee will be noticeably hotter for longer.
2. Insulated Your Stoneware Mug
People use tea-cosies on tea pots for a reason. The material is insulating and helps keep the tea hot for longer.
While not as a common a mug cosy or some kind of cover for your mug will do the same thing and keep your coffee hot for longer.
3. Use a Lid
Most stoneware mugs don't come with lids so this may not be possible but hot coffee gives off steam.
As the steam escapes your cup it takes a lot of heat with it cooling down your coffee. Using a lid traps the steam and thus keeps the heat in your coffee for longer.
Glass Keeps Coffee Hot Longer Than Stoneware
Apparently (if the cups were the same thickness) a glass coffee cup would keep your coffee hot longer than stoneware would.
According to Thermtest the thermal conductivity (or transfer of heat).
- Stainless steel – 14.3 W/mK
- Ceramic – 3.8 W/mK
- Glass – 1.1 W/mK
The higher the conductivity the faster heat moves through the material and escapes to the outside air, cooling down your coffee to room temperature.
Glass is slightly more insulating than stoneware so if both cups were the same thickness the glass cup would keep your coffee warmer for longer than your stoneware cup. But the difference is minimal.
Double Walled Ceramic or Glass Mugs Keep Coffee Hot Even Longer
One way to have your beautiful stoneware and hot coffee too is to get a double walled ceramic mug.
These have an inner and outer wall with air in between.
Because air is a better insulator than ceramic the heat finds it much harder to escape and it'll keep your coffee hot for longer.
There are a lots of different double walled ceramic mugs out there to choose from. I personally like the Mora double walled ceramic mug as it's beautiful, affordable, durable and dishwasher safe.
Vacuum Insulated Mugs Keep Coffee Hot The Longest
Where stoneware ceramic has a thermal conductivity of 3.8 W/mK the thermal conductivity of a vacuum insulated mugs is closer to 0.006 W/mK.
That's a HUGE difference and one of the reasons insulated coffee mugs are the type of cup that keeps coffee hottest the longest.
Where a ceramic mug might keep your coffee hot for 20-30 minutes a vacuum insulated stainless steel mug can keep coffee hot for UP TO 12 HOURS!!!
If you want to know which vacuum insulated coffee mug keeps coffee hot the longest check out my article on the best vacuum insulating mugs ranked by performance.