If any is left over, store it in a thermos bottle - not on a burner or hotplate. If coffee is left on a heated surface for more than a few minutes, the aromatic compounds that make it taste good will begin to break down and the water in the coffee will evaporate, leaving behind a soup of bad-tasting chemicals. I take coffee black, Do not store coffee in the refrigerator. Coffee is to be kept in an airtight container and stored in a cool, dark, dry place. Putting beans in the refrigerator is not good, even if you use an airtight container.
Refrigerators tend to be both damp and full of odors.
There are many methods of brewing coffee. We will examine three of the best. The espresso method produces a very deep, rich coffee. Since it is so strong, many people assume it has more caffeine than coffee brewed by other methods, but it has about the same amount of caffeine per serving as other types of coffee. This is for two reasons.