I should note that my personal roast ... is Starbucks's burly, staple espresso. If you walk into the coffee shop and order a latte or an Americano, the shot is likely pulled from these beans.

The answer to that is the same as to what makes all espresso taste different from coffee — how the beans are roasted, ground, and brewed. To make the Starbucks Reserve Espresso, Starbucks ...