The Coffee Tree
The Coffea Arabica is the most interesting of the coffee species. At first glance, all Arabica trees look very similar, however, if you look closer there are many differences between the trees, which are determined by the variety of Arabica being grown.
The varieties of the Arabica trees yield different amounts of fruit, in different colours, and some carry the fruit in clusters, while others have fruit evenly spaced down their branches.
There are also big differences between the leaves of plants of different varieties. Most importantly, there are differences between the cup characteristics when the seeds of these varieties are harvested and brewed. The range of varieties have different qualities of flavour, and also have different mouthfeels.
From Seed to Tree
Established coffee farms have a nursery in which to raise seedlings before planting them out on the farm ready for production. The coffee beans are first planted in rich soil, and will soon germinate. The bean itself is then lifted out of the ground by the developing shoot. The shoots look strangely, like a roasted coffee bean has been attached to the top of a thin green stem, and they are often referred to as 'soldiers'.
Not long after this, the bean bursts open to reveal its first leaves. Coffee plants grow very quickly and after 6-12 months, they can be removed from the nursery into production.
A coffee farmer will have to be patient and wait around three years for a newly planted tree to fruit properly.
Blossom & Fruit
The majority of coffee trees have one main harvest per year, although coffee trees in some countries have a second harvest. The second harvest is often smaller and of a slightly lower quality.
The cycle is triggered by a prolonged period of rainfall. This rainfall causes the trees to bloom, producing lots of beautiful white blossom flowers with a strong scent that is reminiscent of Jasmine.
Insects such as bees pollinate the flowers, although Arabica is able to self pollinate, meaning that unless they are knocked off the tree by bad weather, the flowers always yield fruit. It can take up to nine months before the fruits are ready to harvest from the trees.
Unfortunately, coffee cherries do not ripen uniformly. This means the coffee producer has a difficult choice to make when harvesting the fruit. They can harvest all the fruits from each tree at the same time and have a mixture of unripe and overripe coffee cherries, or they can pay pickers to do multiple passes of the same trees so each cherry is harvested when it is perfectly ripe.
Source: James Hoffman - The World Atlas of Coffee (2nd Edition)