HISTORY

According to a coffee history legend, an Arabian shepherd named Kaldi found his goats dancing joyously around a dark green leafed shrub with bright red cherries in the southern tip of the Arabian Peninsula.  Kaldi soon determined that it was the bright red cherries on the shrub that were causing the peculiar euphoria and after trying the cherries himself, he learned of their powerful effect.  The stimulating effect was then exploited by monks at a local monastery to stay awake during extended hours of prayer and distributed to other monasteries around the world.  Coffee was born.

Despite the appeal of such a legend, recent botanical evidence suggests a different coffee bean origin. This evidence indicates that the history of the coffee bean beagan on the plateaus of central Ethiopia and somehow must have been brought to Yemen where it was cultivated since the 6th century.  Upon introduction of the first coffee houses in Cairo and Mecca coffee became a passion rather than just a stimulant.

THE COFFEE PLANT

The coffee plant is a woody perennial evergreen dicotyledon that belongs to the Rubiaceae family.  Because it grows to a relatively large height, it is more accurately described as a coffee tree. It has a main vertical trunk (orthotropic) and primary, secondary, and tertiary horizontal branches (plagiotropic). 

TYPES

While there are several different coffee species, two main species are cultivated today.  Coffea arabica, known as Arabica coffee, accounts for 75-80 percent of the world's production.  Coffea canephora, known as Robusta coffee, accounts for about 20 percent and differs from the Arabica coffees in terms of taste. While Robusta coffee beans are more robust than the Arabica plants, but produces an inferior tasting beverage with a higher caffeine content.  Both the Robusta and Arabica coffee plant can grow to heights of 10 meters if not pruned, but producing countries will maintain the coffee plant at a height reasonable for easy harvesting.

GROWTH

Three to four years after the coffee is planted, sweetly smelling flowers grow in clusters in the axils of the coffee leaves.  Fruit is produced only in the new tissue.  The Coffea Arabica coffee plant is self-pollinating, whereas the Robusta coffee plant depends on cross pollination.  About 6-8 weeks after each coffee flower is fertilized, cell division occurs and the coffee fruit remains as a pin head for a period that is dependent upon the climate.  The ovaries will then develop into drupes in a rapid growth period that takes about 15 weeks after flowering.  During this time the integument takes on the shape of the final coffee bean.  After the rapid growth period the integument and parchment are fully grown and will not increase in size.  The endosperm remains small until about 12 weeks after flowering.  At this time it will suppress, consume, and replace the integument.  The remnants of the integument are what make up the silverskin.  The endosperm will have completely filled the cavity made by the integument nineteen weeks after flowing.  The endosperm is now white and moist, but will gain dry matter during the next several months.  During this time the endosperm attracts more than seventy percent of the total photsynthesates produced by the tree.  The mesocarps will expand to form the sweet pulp that surrounds the coffee bean.  The coffee cherry will change color from green to red about thirty to thirty-five weeks after flowing.

Source: coffeeresearch.org