Corelle Country Cottage

I would prefer an answer based on a cup of coffee Corelle Country Cottage.

Depends on temperature. the air around you. If you're outside and it's cold, it will get cold quickly. Every cup will cool w / in a short period of time, no matter what.

It depends on the temperature of your coffee when put in the mug. They do not seem better than others I have. The sandstone of good works.

5-10 minutes. 1 minute if you really want is hot hot hot.

hot as a glass mug would be, if you want to keep it hot, use an insulated travel mug

for about 10-20 minutes. at least mine.