Robusta Coffee is coffee made from the beans of the Coffea canephora plant, the origins of which are in Africa. Robusta coffee is notoriously bitter and is used primarily in instant coffee, espresso, and as a filler in certain blends of ground coffee. Many people think that Robusta has an oatmeal-like taste, somewhere between neutral and harsh. Unroasted Robusta beans smell sort of raw-peanutty.

Source: The Roasterie