Methods of Coffee Harvesting
The two methods of harvesting coffee are selective harvesting and strip harvesting. Each has advantages and disadvantages.
Selective harvesting is the picking of only ripe coffee fruit by hand. Unripe coffee is left on the tree for future harvesting. Overripe coffee can either be left on the tree (not recommended) or picked and kept separate from the ripe fruit (recommended). After several weeks the picker will go back and again pick only ripe fruit. This process is repeated until the producer determines that it is no longer worthwhile to harvest.
Pickers spend the day picking ripe fruit and filling their baskets. Full baskets are periodically emptied into a larger collection bag. At the end of the day, the harvest is spread out and unripe or overripe fruit as well as any foreign debris that accidentally made their way into the ripe coffee are culled. The coffee is then taken to be weighed, and payment is apportioned by weight.
Advantages of Selective Harvesting
- Only ripe fruit are picked, resulting in a lower percentage of unripes in the harvested coffee and higher prices for producers.
- Because the coffee is picked by hand, the trees can be planted on steep slopes that are common to the topography of many coffee regions, resulting in more efficient use of farm land.
Disadvantages of Selective Harvesting
- Hand picking requires a large rural labor force willing to work for minimal pay.
- As wages increase, producers are less able to afford the labor cost of selective harvesting.
- Increasingly urban populations are reducing the available rural workforce.
The alternative to selective harvesting is strip harvesting. Here all coffee fruit are mechanically “stripped” from the coffee tree at once, resulting in harvested lots of varying maturation levels.
There are three common ways that coffee is strip harvested.
In the first method, pickers place a canvas on the ground. They then grab the branch next to the trunk with their hands and pull outward, knocking all of the fruit onto the ground. After doing this with all branches and trees for the length of the canvas, the pickers then collect the coffee in bags and take it to be weighed. Pickers are usually paid by weight or volume.
The second strip harvesting method is similar to the first but with some mechanical assistance. Here pickers use derricadeiras, mechanical strippers that look like Freddie Kruger’s hands attached to a weed whacker. As with the previous method, the pickers first put down a canvas. They then use the mechanical strippers to knock all of the coffee onto the canvas. The accumulated coffee is then put into bags, which are weighed at the end of the day.
The third way to strip harvest coffee is with a mechanical harvester. These machines, first introduced in the early 1970s, use vibrating and rotating mallets to knock the coffee fruit off the tree into collection units. They can be calibrated to minimize the yield of unripes by adjusting rotation and vibration rates as well as the speed at which the mechanical harvester moves through the rows. Another common technique is to remove the bottom mallets at the beginning of the harvest since the coffee on the top of the tree normally ripens more quickly. Later, the lower mallets can be added to harvest fruit from the same plants, this time from the lower section of the plants. This type of selective harvesting requires very flat topographies to accommodate the heavy machinery.
Advantages of Strip Harvesting
- Strip harvesting requires far less labor to complete.
- Harvesting can be completed more quickly.
Disadvantages of Strip Harvesting
- Strip harvesting produces lots of various levels of maturation, which, if not separated, can lead to disuniform drying and lower quality product.
- To achieve optimal quality, coffee producers must have adequate post-harvest technologies such as pulpers and optical sorters.
- The heterogeneous lots produced by strip harvesting result in higher percentages of unripes, which reduce the quality and sale value of the final product, meaning less profit for producers.
Which Harvesting Method to Use?
Historically, selective harvesting has been the predominant means of harvesting coffee. However, in regions with scarce rural labor and higher wages, such as Hawaii and Brazil, some forms of mechanized harvesting are growing in prevalence. The choice of harvesting method is largely based on the availability and cost of the labor supply, but also on topography, post-harvest infrastructure, and desired coffee quality.
(all photos by Joel Shuler)