Producing a great cup of coffee involves so many steps, no surprise there. Every step requires skill and not just roasting, or brewing. Early steps like harvesting the coffee cherries also play as determinant factor in how the final cup might taste like.
The big challenge with coffee cherry harvest is not all cherries in a single bunch ripe at the same time. The best time to pick a cherry is when it is red. But here is the question; how red? The thing is, coloration in ripe cherries differ among different varieties of coffee. So much depends upon the degree of ripeness of coffee cherry and yet there are so many challenges in picking the right cherry at the right time.
The best way to make sure cherries are picked selectively is to get the job done manually via trained labor. It is a time consuming, labor intensive job. But to maintain the selective picking of coffee cherry is yet still challenging because the manual labor hired to get the job done is paid by the weight of coffee they collect at the end of the day and not the quality. Inspecting the coffee cherry bunches carefully before picking, slows the whole process down that means less cherries collected and lesser the labor get paid.
Another hindrance in the way of selective picking is the size of plantation. Larger the farm, the lesser is the attention received by each coffee tree. From green to yellow, to orange to red and finally dark purple, coffee cherries keep completing their natural course of ripeness and when not picked at the right time, fruit begins to ferment and finally rot. Sometimes a cherry is only half way ripe that is half red and half yellow and leaving or picking is a tricky decision for the picker then, as the cherry may go over the right point of ripeness by the time the tree is visited again for harvesting.
More even final harvest is obtained by hand sorting all picked cherries. Green (under-ripe) and brown to black (over-ripe/rotten) cherries are removed. Some places also use equipment for sorting but affordability is a limiting factor in arranging for such equipment. Hand picking enables every batch to be more even, consisting mostly of evenly ripe cherries.
Perfect ripe cherries tend to be very sweet. The sweetness is incorporated into the beans as well. So a good coffee comes from a batch comprising of well-ripe cherries, tending to be light sweet and clear.
Bottom line is one important requirement; picking the ripe cherry, is not easy to fulfill as it may appear. That doesn’t mean finding a great cup is impossible. But only lucky ones get their hands on a lot that consists of a lucky great batch of perfectly ripe cherries harvested someday which were then carefully processed, roasted and brewed to thrill their taste buds.