Food commodities are rising in price and that includes coffee, but the coffee bean market is also changing. Out of 100 species of coffee, just two dominate: Arabica and Robusta. And of those two, Arabica has been the bean to beat. Because of a higher lipid and sugar level, it is considered sweeter and smoother than its Robusta cousin. It is also more expensive because the higher demand runs into harder to grow. Robusta is more bitter in taste due to higher caffeine (2.7 percent versus 1.5 percent for Arabica), which along with a higher content of chlorogenic acid helps to deter pests and helps boost yield.  Adverse weather has led to smaller, more erratic Arabica crops, plunging stocks to their lowest level since February 2000. The pr...