Rob bought me one of the electric tiny hotplate kind of thingy to keep my coffee warm one Christmas. The problem was the gadget made the coffee too warm, and then the coffee tasted burnt.
I checked the price of this little modern keep coffee warm jewel, and it was $99. Nope, that is not going to be on my desk anytime soon! Plus, as someone said, it does tip, so that is another nope.
All that being said, I am a coffee snob. I worked as one of the first baristas in my small town 30 years ago, and I soon learned to tell good coffee from not so good coffee. No Folgers in my cup, although if I am visiting someone and that is all, there is on hand, I will drink a cup of it. As for instant! Nope, I do not like that stuff at all! Although I did go through a phase where a guy named Raz introduced me to INKA loaded with brown sugar and cream. Yummy, but oh my, I did gain a lot of weight that winter! So now, Inka is a nope for me.
My favorite coffees are Costa Rica and Kenya’s whole bean. However, I have fallen under the Keurig spell of making coffee one cup at a time, and I now drink a decaff French roast as I like my coffee strong.
To keep my coffee hot, I use a stainless steel Copco coffee mug. Yep, these are my two colors. They sell them at Costco for half the price that the mugs sell for in the retail stores.
I also have a Hot Pink Hydroflask mug. For some reason, when I drink out of it, I think of @KissMyPeach I was lucky to find it on a 50% off sale.
Both do a great job of keeping my coffee hot because when I use my regular mug, my coffee gets cold like many others here have indicated. Then I use @weeyin’s microwave method to warm my coffee up.