First of all lets start by looking at the Arabica beans (Coffea arabica), named by the Arabs. This is always the more expensive of the two. These trees are grown in semi-tropical climates near the equator, both in the western and eastern hemispheres, at high altitudes. Because ripe Arabica cherries (green beans) fall to the ground and spoil, they must be carefully monitored and picked at intervals, which increases production costs. Also the Arabica beans are more prone to disease, whilst the high concentration of caffeine in Robusta beans helps protect them from pests.
Robusta (Coffea canephora), which is grown exclusively in the eastern hemisphere, also thrives in equatorial climates, but at low altitudes. Their cherries require less care since they don't fall off, but remain on the tree after they ripen. Robusta beans have twice the amount of caffeine of Arabica, but they also have less flavor.
Bean Bag Beans
The perfect blend is always a blend of coffee beans from different origins. It could be 100% Arabica beans or a mix of robusta and Arabica together. Usually the better coffee blends are always a mix of the 2 families, where the Arabica gives the flavour and the character and the robusta adds the crema and kick of the caffeine.
Which ever blend you use, the main question is always what kind of Arabica or Robusta beans are they?
There are more than 100 different varieties of Arabica and Robusta coffee beans in relation to the country of origin. The quality of the coffee bean can vary widely within a single region and depends upon a large number of factors. The producer, their harvest methods and the year of growth can significantly affect the taste, aroma and quality of the beans.
Don't be fooled by the high price, or by the 100% Arabica labels. Ask where the beans are grown before you buy. As a general rule, the best Arabica Beans come from South America, whilst the best Robusta beans are usually sourced from India.
It also preferable to buy the coffee beans already packed in a special aluminum foil bag. Also make sure that the same bag has the special one-way valve on its extremity. Indispensable for keeping the coffee at its optimum state.
Stay away from the beans stored in the supermarket dispenser. Although they look traditional and glamorous, they often store old beans and can be a breeding ground for insects.