Waking up is hard to do. Eyes are heavy, the air is cold, and the body longs to retreat back to the warm embrace of a blanket. For many the only way to combat the curse of the morning is a good cup of coffee. As students, many of us rely on coffee, or more specifically caffeine, for a mild, relatively harmless jumpstart. Many of us even start to develop certain preference on how the beverage is made. Those who prefer flavour may order a cappuccino, others who need an immediate jolt of energy will order an espresso. The thing is, the former of this group has subjective taste and is not relevant to this blog, and the latter is wrong… kind of.
According to this study, the typical 8 oz cup of regular coffee will contain about 92.5 mg of caffeine on average, and an expression will contain about 40 mg. Simple numbers clearly demonstrates that the average cup of coffee can contain more than half the caffeine than an espresso (not accounting for variables like temperature, milk content, brew style, etc.) The thing is human intuition is lousy, even when the numbers are in front of us.
The way a person drinks their coffee makes all the difference, more specifically the size of their cup is what changes things. You see, most people take their espressos in 2 oz shots. Per oz, regular coffee divides its caffeine content relatively evenly to about 8-15 mg/oz according to the same study. An espresso, on the other hand, contains 30-50 mg/oz due to the concentration of caffeine (again, not considering other variables.)
The question is, why do people believe espressos contain more caffeine? A possibility explanation is that the name sounds a little like “express.” A more likely explanation again comes from the way people drink their coffee. Espressos are consumed quickly in shots, and coffee is usually consumed slower. We assume the immediate feeling of energy must come from a high amount of caffeine, but that is only half correct. It is a correlation that does not match its causation.
The main lesson here reinforces what might as well be the class motto, our intuition is lousy, but straight numbers are not the cure. In terms of purpose, espressos do their jobs by giving people quick energy, and although caffeine content does not support that idea, caffeine concentration does.