Although it tastes “stronger”, dark roasted coffees actually have LESS caffeine than medium or light roasts. The longer a coffee is roasted, the darker it becomes and the more caffeine burns off during the process. Similarly, contrary to popular assumptions, espresso coffee actually contains about one-third of the caffeine of a brewed cup of coffee. This is partially due to the fact that espresso is typically made using top premium arabica beans which have a lower caffeine content than robusta beans, which are found in many coffee blends used for standard brewing. Also, in the espresso brewing method, water is in contact with the grounds for only 20 to 25 seconds and extracts less caffeine than methods that put water in contact with the grounds for several minutes.