title_body: What is the difference between Robusta and Arabica?
upvoted_answer: One reason that the taste isn't as good for Robusta is that it has more caffeine compared to Arabica. Which may sound like a positive thing but caffeine carries a bitter taste which makes it an unpleasant drink. In fact the Robusta bean has 2.7% caffeine content, almost double the 1.5% of Arabica.
  Arabica contains almost 60% more lipids and almost twice the concentration of sugar than Robusta. This factor also probably has a big impact on why we prefer the taste of Arabica.
  From a price perspective, green beans of Robusta is about half the price of Arabica green beans on the commodity market.
  Robusta is easier to tend to on the farm, has a higher yield and is less sensitive to insects - the extra caffeine is a chemical defense for the coffee seed as the quantity in the Robusta is toxic to bugs.
  
  All of these factors help bring up the supply and lower the input costs for farmers to produce. With this more attractive price point, a lot of roasters back in the day would add Robusta to their blend in an attempt to reduce their costs and increase their profits. When coffee was initially sold in the 1900s the quality of coffee slowly and slowly deteriorated in an effort for companies to squeeze the most profit.
  Where you’ll find it: Nowadays, it’s not often you’ll find Robusta in a coffee blends or in coffee shop. If you’re drinking instant coffee? Well, that’s probably all Robusta… but you probably don’t care very much about taste. In your espresso blend? That’s a mixed bag. Literally. Oddly enough, Robusta is still widely used as part of espresso blends – specifically Italian style blends. It is said to help improve the crema.
  One thing to note is despite the association with Arabica of being higher quality, and Robusta as being lower quality, it’s not always the case. Top notch specialty Robusta coffee will usually taste as good as or better than low end Arabica. However, high end Robusta isn’t widely used or available. Rather, Robusta is usually used as a filler or cost reducer.
  
  Robusta beans are much more circular, whereas Arabica are more oval.
  Chlorogenic acid is a significant antioxidant and an insect deterrent. Robusta is 7-10% CGA and Arabica has 5.5-8% CGA.
  
  Sourced from The Roasters Pack.