The Arabica beans are light, bright and provide an earthy fragrance to the coffee. They bring out flavors like nuts or chocolate but they can also be weaker in flavor at times. The Robusta beans are much more powerful than the Arabica bean with a deep smooth flavor which you might prefer if you're adding milk, sugar, or both to your espresso drink. Both types of coffee produce espresso that is strong enough to withstand cream, sugar, and other additions that some people might want for their morning cup of joe. Picking one type of bean vs the other is usually up to personal taste but you should take into account what drinks you will be making. The best espresso beans are the ones right in front of you ready to be used in espresso machines.