Coffee harvesting is the fundamental first step in the journey of the coffee bean, involving the careful removal of ripe coffee cherries, the fruit of the coffee plant, from the branch. The decision of when and how to harvest has an immediate impact on the ultimate flavor profile and quality of the brewed coffee. The harvesting methods influence the consistency of ripeness, which determines the balance of sugars and acids that develop during subsequent processing.
Determining Peak Ripeness
The most common indicator farmers use to determine the perfect time for harvest is the visual cue of color change in the coffee cherry. Cherries begin as small, hard, green fruits and gradually progress through stages of yellow or orange before reaching their final mature color. For most Coffea arabica varietals, peak ripeness is signaled by a transition to a deep, vibrant red hue, correlating with the highest sugar content.
Certain varietals, such as some Bourbon or Catuai mutations, ripen to a bright yellow instead of red, requiring farmers to adjust their visual assessment. This final color change corresponds with the maximum accumulation of sugars and dry matter within the cherry pulp. Ripeness does not occur uniformly; a single branch often holds green, ripe, and overripe cherries simultaneously. This necessitates constant monitoring and a strategic approach to picking to ensure only the highest quality fruit is collected.
Selective Hand Picking
Selective hand picking is the standard method for harvesting high-quality specialty coffee, prioritizing flavor integrity over speed or volume. This labor-intensive technique requires workers to manually inspect each branch and pick only the cherries that have reached optimal ripeness. Unripe (green) or overripe cherries are intentionally left on the tree to continue maturing.
Because not all cherries ripen simultaneously, workers must return to the same coffee trees multiple times over several weeks, a practice called making “rounds.” This ensures a highly uniform batch of fruit, minimizing the inclusion of immature beans that introduce undesirable grassy or sour notes. Due to the precision and repeated effort involved, this method is significantly more expensive and time-consuming. It is reserved for high-value Arabica crops grown on steep terrain where mechanical harvesting is impossible.
Strip Picking and Mechanical Methods
In contrast to the selective method, strip picking focuses on efficiency and high-volume production. This process involves workers grabbing a branch and forcefully stripping all the cherries off in a single motion, regardless of ripeness level. This results in a mix of ripe, underripe, and dried cherries, along with leaves and debris. The trade-off is a lower average quality in the resulting coffee due to contamination from premature and defective beans.
For large, flat-terrain farms, particularly in countries like Brazil, mechanical harvesters are employed to rapidly process vast tracts of land. These large machines use vibrating rods or shakers to dislodge the cherries into collection bins. While this dramatically reduces labor costs and increases speed, it collects all fruit indiscriminately, mimicking strip picking. The use of these methods necessitates extensive post-harvest sorting to remove lower-quality cherries before processing begins.
Initial Post-Harvest Handling
The period immediately following the harvest is crucial for maintaining quality, even before the cherries are sent for wet or dry processing. The first action involves immediate dry-sorting to remove large foreign matter, such as leaves and small sticks, which can introduce off-flavors or damage equipment. This initial triage also includes separating visibly damaged or clearly unripe fruit from the main lot.
A more precise sorting technique is the use of water tanks for float sorting. When the harvested cherries are submerged, those that are underripe, overripe, or defective often have a lower density due to underdeveloped seeds or internal air pockets, causing them to float to the surface. These “floaters” are skimmed off and separated from the denser, fully ripe cherries that sink to the bottom. This step is performed quickly to prevent uncontrolled fermentation and is a fundamental quality control measure that ensures only the best fruit moves forward to the next stage of coffee production.