About Coffee

Coffee is the second largest traded commodity in the world, after oil. It is believed that coffee was first consumed in the 9th century in Ethiopia. From there it spread to Egypt and Yemen and by the 15th century it had been introduced to Persia (now Iran), Turkey, Armenia and northern Africa. From there it spread to Italy, then the rest of Europe and then northern America. Today it is one of the most popular beverages in the world and recognized everywhere.

Coffee typically grows in regions that offer moderate sunshine and rain, steady temperatures around 70°F (20°C), and rich, porous soil. There are two main coffee trees – Arabica (the better beans) which make up about 70 percent of the harvest and Robusta (the harsher beans) which account for about 30 percent.

Coffee Growing

Coffee is a deciduous shrub-like tree. Most trees are pruned back each year to less than 8 feet and every 8-10 years the tree is pruned almost to the ground. Most trees can have up to 50 years of good coffee production. Most coffee cherries come from Robusta or Arabica coffee trees. At Pónaire, we use only Arabica beans as they are of higher quality, lower in caffeine (50% less than Robusta) and more naturally resistant to disease. All coffee beans start out green and turn bright red when they are ripe and ready to be picked. The coffee cherry matures on the branch for 5-6 months. It is important to note, however, that the beans do not ripen at the same time and therefore high quality coffee is hand-picked and harvesting is done by continuous passes on the small trees until all the ripe cherries have been picked. After picking, the cherries are processed to extract the green coffee beans inside. This process is either a dry-process or wet-process.

Wet Processing

In the wet-process method, the cherry must be de-pulped within 6-12 hours after picking or it will begin to rot. In wet-processing the coffee cherries are put into large water tanks – ripe cherries sink, unripe one float. The floaters are skimmed off the surface and the ripe cherry enters the pulper. The external skin of the coffee cherry is removed and the fruity part is exposed. The coffee bean is then put into a water tank to ferment. Fermentation is natural and begins to breakdown the remaining pulp. This process takes from 24-72 hours (depending on the altitude) and then the beans are channeled out to patios to dry. The beans are left on the patios for 4-8 days until they contain about 12% moisture and then they are sent to the dry mill. Here it is removed from parchment, sorted by density and screen, hand prepped and bagged for export. When properly done, wet processing ensures that the qualities of the coffee beans are better preserved, producing a green coffee which is homogeneous and has few defective beans. Hence, the coffee produced by this method is usually regarded as being of better quality and commands higher prices.

Dry Processing

In dry-processing, the ripe cherries are laid out on patios to sun-dry. When the moisture content is down to about 12%, the seed is milled out of the cherry. Dry process is also known as unwashed or natural coffee and it is the oldest method of processing coffee. The entire cherry after harvest is first cleaned and then placed in the sun to dry on tables or in thin layers on patios.

Cleaning: The coffee cherries are usually sorted and cleaned, to separate the unripe, overripe and damaged cherries and to remove dirt, soil, twigs and leaves. This can be done by winnowing – commonly by hand using a large sieve. The ripe cherries can also be separated by flotation in washing channels near the drying areas.

Drying: The coffee cherries are spread out in the sun, either on large concrete or brick patios or on matting raised to waist height on trestles. As the cherries dry, they are raked or turned by hand to ensure even drying and prevent mildew. It may take up to 4 weeks in some areas before the cherries are dried to the optimum moisture content, depending on the weather conditions. On larger plantations, machine-drying is sometimes used to speed up the process after the coffee has been pre-dried in the sun for a few days. The drying operation is the most important stage of the process, since it affects the final quality of the green coffee. Coffee cherries that have been overdried will become brittle and produce too many broken beans during hulling (broken beans are considered defective beans). Coffee that has not been dried sufficiently will be too moist and prone to rapid deterioration caused by the attack of fungi and bacteria. The dried cherries are stored in bulk in special silos until they are sent to the mill where hulling, sorting, grading and bagging take place. All the outer layers of the dried cherry are removed in one step by the hulling machine. The dry method is used for about 95% of the Arabica coffee produced in Brazil, most of the coffees produced in Ethiopia, Haiti and Paraguay, as well as for some Arabicas produced in India and Ecuador. Almost all Robustas are processed by this method. It is not practical in very rainy regions, where the humidity of the atmosphere is too high or where it rains frequently during harvesting.

Milling, Hulling & Polishing

One of the final steps in coffee processing involves removing the last layers of dry skin and remaining fruit residue from the now dry coffee, and then cleaning and sorting it. The first step in dry milling is the removal of what is left of the fruit from the bean, whether it is the crumbly parchment skin of wet-processed coffee, the parchment skin and dried mucilage of semi-dry-processed coffee, or the entire dry, leathery fruit covering of the dry-processed coffee. Hulling is done with the help of machines, which can range from simple millstones to sophisticated machines that gently whack at the coffee. This is an optional process in which any silver skin that remains on the beans after hulling is removed in a polishing machine. The purpose of this process is to improve the appearance of green coffee beans and eliminate a byproduct of roasting called chaff. We consider this to be an unnecessary step and detrimental to the taste by raising the temperature of the bean through friction which changes the chemical makeup of the bean.

Cleaning and Sorting

Sorting by Size and Density: Most fine coffee goes through a battery of machines that sort the coffee by density of bean and by bean size, all the while removing sticks, rocks, nails, and miscellaneous debris that may have become mixed with the coffee during drying. First machines blow the beans into the air; those that fall into bins closest to the air source are heaviest and biggest; the lightest (and likely defective) beans plus chaff are blown in the farthest bin. Other machines shake the beans through a series of sieves, sorting them by size. Finally, a machine called a gravity separator shakes the sized beans on a tilted table, so that the heaviest, densest and best vibrate to one side of the pulsating table, and the lightest to the other.

Sorting by Color: The final step in the cleaning and sorting procedure is called color sorting, or separating defective beans from sound beans on the basis of color rather than density or size. Color sorting is the trickiest and perhaps most important of all the steps in sorting and cleaning. With most high-quality coffees color sorting is done in the simplest possible way: by hand. Teams of workers pick discolored and other defective beans from the sounds beans. The very best coffees may be hand-cleaned twice (double picked) or even three times (triple picked). Coffee that has been cleaned by hand is usually called European preparation; most specialty coffees have been cleaned and sorted in this way. Color sorting can also be done by machines. However, these machines are currently not used widely in the coffee industry because they are very expensive and the technical skills required to run and maintain them is hard to find in coffee growing regions. Also, sorting coffee by hand supplies much-needed work for the small rural communities that often cluster around coffee mills.