The coffee tree comes from a large family of evergreen shrubs; to call it a tree may be somewhat of an exaggeration. For much of coffee’s recent history, the species and variety of the tree was chiefly a concern of coffee farmers’ efforts to combat disease and pests along with increasing crop yields. Recently, coffee roasters have taken an interest in coffee varieties for a very different reason: marketing.
While coffee originated in Ethiopia, it was in neighboring Yemen that Turkish farmers first cultivated it on a commercial scale. Undoubtedly, the Turks could have selected any number of species and varieties to plant, but the one they chose was most likely for its fine flavor since there were other hardier, and greater producing species to be found. The Turks closely guarded their treasure, and how seeds were finally secreted away is a source of legend. This species of coffee took its name from whence it came: Arabia; taking on the nomenclature Coffea Arabica, which today accounts for 80% of the world’s production.
The spread of Arabica coffee around the world was based on a very limited number of trees. Seven berries were taken by Baba Budan to India; a small shipment was taken to the French colony of Reunion; and the tree taken from Java to Amsterdam in 1706, together with its offspring in Paris, which provided all the planting material for South and Central America. Consequently, the whole genetic base of the Arabica coffee industry is very narrow. As demand for coffee grew, large areas - sometimes entire countries – became dedicated to coffee production, revealing weaknesses inherent in propagating a single species. Since the coffee tree is an evergreen shrub having broad leaves, it is a tempting target for pests and disease. This became glaringly clear in Sri Lanka - once one of the world’s largest producers – that ultimately lost its entire crop to disease in the late 1800’s, never to recover. Experience has led farmers to seek alternatives through inbreeding to increase resistance, and to boost crop yield. Since the coffee tree is an inbreeder, natural mutations occasionally occurred. These mutations often displayed characteristics that allowed them to adapt to specific growing conditions. Inbreeding has led to a number of hybrids of the Arabica species that are referred to as varieties or cultivars. These cultivars all derive from the original typica variety from Yemen and the bourbon variety from the Reunion. The two varieties are considered identical from a herbarium perspective.
Hybrid varieties have become so popular that in many countries they greatly outnumber the original typica and bourbons and, in some cases, have completely replaced them. For the most part, coffee connoisseurs were quite unaware of this change until recently. Hybridization began in earnest after the Second World War as part of the “Green Revolution” that occurred throughout the world’s agricultural industry. This movement was characterized with a change in growing practices to increase production and simplify labor practices through mono-cropping and heavy use of fertilizer and pesticides. Since coffee contributes significantly to the GNP of many equatorial nations, government sponsored research institutes and boards were created to assist farmers in the latest methods in what came to be known as technified farming. Technified farming encouraged the removal of traditional multi-story shade canopies in favor of specialized shade or full sun growing techniques.A new form of hybrid propagation was encouraged to combat disease and pest outbreaks due to intense mono-cropping. This new hybrid is referred to as interspecific hybrids. Interspecific hybrids are cross bred from outside the Arabica species, most notably the Robusta species. These hybrids display negative taste characteristics that are quite recognizable to the trained coffee professional. The success of interspecific hybrids may have increased yields and forged a (temporary) bulwark from disease and pests, but many professionals within the coffee industry believe that this success has come at a cost to flavor quality.
The confusion between inbred cultivars and interspecific hybrids has led to a resurgence of interest in specific varieties, and what some may describe as the heirloom varieties of bourbon and typica, and an “Indiana Jones” style quest to find the ultimate cultivar. The recent interest in the Geisha variety best illustrates this phenomena. Some roasters, as a fashionable method to display their commitment to quality, now actively promote particular varieties. What is important to remember however is that the extreme narrow genetic base for the Arabica species makes taste variation quite negligible. It is difficult enough, if not impossible, to distinguish a flavor variance between the typica and bourbon variants, much less variants within cultivars. Any perceived taste variation is more likely resulting from external variables.
Ultimately, flavor quality depends on microclimate variables, ecological stewardship and processing methodology. Flavor profiles are the result of specific locations, the best cultivar is the one that thrives best in its location. Coffees coming from technified plantations are thin, acidy, and flavorless due to the low nutrient quality of their environment. Pumping nitrogen fertilizer into poor soil conditions and highly variable temperature conditions does not make for good flavor quality. Coffees coming from rich, biodiverse environments, that are managed in a systematically caring fashion, whether through science or tradition, display fine flavor characteristics that are a snapshot of their environment. Rather than wasting time promoting varietals, roasters would do better promoting micro-climate. Not only would this better promote flavor characteristics, it would reward farms that are healthy stewards of biodiversity.