So, why is reheating coffee such a no-no?
Is there a way to do it without wrecking that special, first-taste buzz?
Simply speaking, warming up coffee just isn’t a good idea.

Some things just don’t work to reheat, and coffee is one of them."
The longer a cup of Joe sits out, the worse it’s going to taste.
Plus, coffee that’s been left sitting will taste more sour due to an increase in acidity.

Warming it up in the microwave won’t reverse the problem.
In fact, it could actually speed up the process.
Coffee is a finished product that gets worse with each attempt to revive it.