Sugar added to coffee. Spoonful of white granulated sugar being added to a cup of black coffee to sweeten it. Coffee is a caffeine- containing stimulant beverage, which is made with beans from the coffee plant (Coffea sp.). Sugar can be obtained from sugar cane or sugar beet plants. The refining process that produces white sugar removes most of its minerals and vitamins. Sugar is high in calories (energy), which if eaten in excess can lead to tooth decay and obesity.