1, the refreshing substance of coffee is caffeine. Caffeine is a xanthine alkaloid compound and a stimulant of central nervous system, which can temporarily dispel drowsiness and restore energy. It is used to treat neurasthenia and coma and resuscitation in clinic. Coffee, tea, soft drinks and energy drinks containing caffeine are very popular, so caffeine is also the most widely used psychotropic drug in the world.

Generally speaking, the longer the coffee extraction time, the higher the caffeine content. Because instant coffee is completely extracted, in order to save costs, the degree of extraction is very high, and Robbins special coffee beans will be used in large quantities, so the caffeine content of instant coffee is generally the highest.

3. Although espresso is rich in flavor, the extraction time is very short, generally only 25 seconds, so the caffeine content is the lowest among all extraction methods.