Can espresso really be espresso without Robusta beans blended into it?
Absolutely. In fact, the most famous and respected espresso coffees of Italy are 100% Arabica blends. If you look at a companys product line, you will always see that their most expensive coffee ( typically called superiore or Gold) is 100% Arabica. However, most companies tend to sell blends that have a high content of Robusta beans because this cuts their costs significantly.