The World Atlas of Coffee: From beans to brewing - coffees explored, explained and enjoyed

by James Hoffmann

  Most coffee cherries contain two seeds, which face each other inside the berry, becoming flattened along one side as they develop. Occasionally, only one seed inside a berry will germinate and grow and these are known as peaberries. Instead of having a flattened surface on one side, these seeds are rounded and make up around five per cent of the crop. These peaberries are usually separated from the rest of the crop and some people believe that they have particularly desirable qualities or that they roast in a different way to the flattened beans.

  COFFEE VARIETIES

  The first coffee trees to be cultivated originated in Ethiopia, and this same variety, Typica, is still widely grown today. Many other varieties now exist, some natural mutations and others the result of cross-breeding. Some varieties have explicit taste characteristics of their own, while others take on their characteristics from the terroir in which they are grown, the way they are cultivated and the way they are processed after harvest.

  Few coffee consumers are aware that there are different varieties of the Arabica coffee tree, mainly because much of the world’s coffee always has been, and still is, traded by origin. A particular lot may come from many farms and, by the time of export, no one knows which varieties the contributing producers had grown, only which part of the world it was grown in. This is starting to change, but we still know relatively little about how much impact the variety of the tree can have on the taste of the cup of coffee.

  Please note that the descriptions of the most common varieties below will not include any specific notes on taste, unless there is something definite and distinct. So many factors influence cup quality and, coupled with the lack of organized research on the way this can be influenced by variety, it would be misleading to make any bold claims in these pages.

  VARIETIES AND VARIETALS

  There is often some confusion over the terms ‘variety’ and ‘varietal’. Varieties are genetically distinct variations of a single species, in this case Coffea arabica, that may show different characteristics in the tree structure, leaves or fruit. ‘Cultivar’ is another acceptable term to use here, as this is just a truncation of ‘cultivated variety’.

  ‘Varietal’ should be used when referring to a specific instance of a variety. When referring to the production of one farm, for example, it would be correct to say that it was one hundred per cent Bourbon varietal.

  TYPICA

  This is considered the original variety from which all other varieties have mutated or been genetically selected. The Dutch were the first to spread coffee around the world for commercial production and this was the variety they took with them. The fruit is usually red and Typica is capable of producing excellent cup quality, though with a relatively small yield compared to other varieties. It is still grown extensively in many different parts of the world and, as a result, is known by several different names including criollo, sumatra and arabigo.

  BOURBON

  This was a natural mutation of Typica, which occurred on the island of Réunion (at the time called Bourbon). The yield is higher than that of Typica, and many in the speciality industry believe that it has a distinctive sweetness, making it prized and desirable. There are various variations in the colour of the fruit: red, yellow and occasionally orange. This variety was grown very widely in the past but in many producing countries it was replaced by higher-yielding varieties. This was at a time when the market had not yet matured sufficiently to reward a high enough price to compensate for the lower yields it produces compared to newer varieties.

  Bourbon

  MUNDO NOVO

  A natural hybrid of Typica and Bourbon, this variety was named after the place in Brazil where it was discovered in the 1940s. It is grown for its relatively high yield, strength and disease resistance, and also for its success at altitudes of around 1,000–1,200m (3,300–3,900 feet) which are common in Brazil.

  CATURRA

  This is a mutation of Bourbon, discovered in Brazil in 1937. Its yields are relatively high, though it has the capacity for overbearing, where the tree produces more fruit than it can sustain and succumbs to die-back. However, good farm management can avoid this situation. This variety has been especially popular in Colombia and Central America, though it is still fairly common in Brazil. Cup quality is considered good, and while quality increases with altitude, yield decreases. There are both red and yellow variations and it is a low-growing variety, often referred to as dwarf or semi-dwarf, popular because they are easier to pick by hand.

  Caturra

  CATUAI

  This is a hybrid between Caturra and Mundo Novo created by the Instituto Agronomico do Campinas in Brazil in the 1950s and 1960s. It was selected as it combined the dwarf characteristics of Caturra with the yield and strength of Mundo Novo. Like Caturra, there are red and yellow varieties.

  MARAGOGYPE

  One of the more easily recognized varieties, Maragogype is a mutation of Typica, first discovered in Brazil. It is notable, and often considered desirable, due to the unusually large size of its beans. The tree also has exceptionally large leaves but a relatively low yield. This coffee is often referred to as ‘Elephant’ or ‘Elephant Bean’ coffee due to its size. The fruits usually ripen red.

  SL-28

  A now prized variety, SL-28 was created in Kenya by Scott Laboratories in the 1930s, selected from a drought-resistant variety from Tanzania. The fruits are red when ripe and the beans are notably larger than average. This variety is considered to be capable of producing a cup with a distinct fruit flavour, often described as blackcurrant. It is quite susceptible to coffee leaf rust, and performs better at higher altitudes.

  SL-34

  This variety was selected from French Mission Bourbon, a variety brought back to Africa from Bourbon (Réunion) and first appearing in Tanzania and then in Kenya. It is also capable of distinct fruit flavours but is generally considered to be inferior to SL-28 in cup quality. It is also susceptible to coffee leaf rust, and the fruits ripen red.

  GEISHA OR GESHA

  There is some debate over the correct name for this variety, though ‘Geisha’ is more commonly used. Gesha is a town in western Ethiopia and, while the variety was brought to Panama from Costa Rica, it is believed to be Ethiopian in origin. The variety is considered to produce exceptionally aromatic/floral cups, and the demand for it has driven up prices in recent years.

  It has gained prominence and popularity dramatically since 2004 when one Panamanian farm, Hacienda La Esmeralda, entered a competition with a Geisha lot. The coffee proved so unusual and distinct that it attracted an incredibly high bid of $21/lb at auction. This record bid was beaten in 2006 and 2007, reaching $130/lb – nearly one hundred times more than a commodity-grade coffee. This has since encouraged many producers in Central and South America to plant this variety.

  Geisha/Gesha

  PACAS

  Pacas is a natural mutation of Bourbon, discovered in El Salvador in 1949 by the Pacas family. It has red fruits and its low-growing habit makes picking easy. Its cup quality is considered similar to Bourbon, and is therefore desirable.

  VILLA SARCHI

  Named after the town in Costa Rica where it was discovered, this is another natural mutation of Bourbon that, like Pacas, exhibits dwarfism. It is currently being bred to produce very high yields, and it is capable of excellent cup quality. The fruits ripen red.

  PACAMARA

  This is a cross between the Pacas and Maragogype varieties, created in El Salvador in 1958. Like Maragogype, it has extremely large leaves, fruit and coffee beans. It also has distinct cup characteristics that can be positively described. It can taste like chocolate and fruit, but it also has the capacity for unpleasantly herbal, onion-like cups. The fruits ripen red.

  Pacamara

  KENT

  Named after a planter who worked on a selection programme in India in the 1920s, this variety was developed for its resistance to coffee leaf rust, though it can be destroyed by new strains of the disease.

  S
795

  Also developed in India, this is a cross between Kent and S288, an older selection resistant to coffee leaf rust. It is widely planted in India and Indonesia, although it is now considered to have lost much of its resistance.

  WILD ARABICA VARIETIES

  Most of the above varieties are genetically extremely similar, as they all stem from one variety, Typica. Many of the coffee trees grown in Ethiopia, however, are not selected cultivars, but are indigenous heirloom varieties that probably result from cross-breeding between different species as well as different varieties. Little work has been done so far to catalogue or explore the genetic diversity and cup quality of these wild varieties.

  Arabica coffee is harvested by machine in Cabo Verde, Brazil. This method of collecting fruit is efficient, but the harvest must later be sorted to select only ripe cherries.

  HARVESTING COFFEE

  Careful harvesting of coffee cherries is fundamentally important to the quality of the resulting cup of coffee. Unsurprisingly, coffee beans harvested from fruit at peak ripeness generally taste the best. Many experts see the harvest as the point at which the quality of the coffee peaks, and every stage thereafter is about preserving quality rather than improving it.

  The greatest challenge in harvesting high-quality coffee is perhaps the topography of the land on which the coffee is growing. Great coffee requires altitude and many coffee farms are located on steep slopes in mountainous areas. Simply navigating between the trees can be difficult, if not downright dangerous. This isn’t true of every coffee farm, however.

  MACHINE HARVESTING

  Brazil has large areas of flat land at high altitude where coffee proliferates. The estates in these areas drive large machines down the neat rows of coffee trees to harvest the cherries. These machines essentially shake the trees until the fruit comes loose. There are numerous downsides to machine harvesting, the biggest being the issue of collecting fruit before it is necessarily ripe. The cherries on the branch of a coffee tree ripen at different rates, so each branch has both ripe and unripe cherries together. The machines do not differentiate and pick all the cherries at once. This means they must be sorted after harvest to separate the ripe from the unripe, and to discard the twigs and leaves that also get shaken off the tree. The cost of the coffee’s production will be lower than any other harvesting method, but at the expense of the quality of the harvest as a whole.

  STRIP PICKING

  A great deal of coffee is still harvested by hand as machines simply cannot operate in hilly areas. One of the faster methods of hand-picking is to strip all the cherries off a branch together with one deft movement. Like machine harvesting, this is a quick but imprecise way to pick the cherries. It doesn’t require expensive equipment or flat land, but still results in a mixed bag of ripe and unripe cherries that must be sorted later.

  HAND-PICKING

  For high-quality coffee, hand-picking remains the most effective way of harvesting. Pickers select only the cherries that are ready for harvest, leaving the unripe fruit on the tree to be picked later. This is hard labour and producers face the challenge of incentivizing their pickers to harvest only the ripe fruit. Pickers are paid by the weight of the fruit they pick, which encourages them to pick unripe fruit to make up additional weight. Quality-conscious producers have to work carefully with their picking teams to make sure they are also paid for uniform ripeness.

  Cherries can be sorted in a flotation tank. Ripe cherries sink to the bottom of the tank and are pumped out for processing while unripe fruit floats to the top and is treated separately.

  FALLEN FRUIT

  Coffee growers collect any fruit that naturally falls off the trees – ripe or not. This is usually collected separately and will become part of the lower quality lots that even the best farms in the world inevitably produce. Leaving fallen fruit on the ground under the trees can cause problems, as they tend to attract pests such as coffee berry borer.

  THE PROBLEMS OF LABOUR

  The cost of hand-picking coffee is proving a growing challenge and contributes a large part of the production costs. This is one of the primary reasons that coffees produced in developed economies – such as Kona coffees produced in Hawaii – are so expensive. In rapidly developing countries, people simply don’t want to pick coffee for a living. Coffee farms in Central America often employ itinerant pickers who travel from country to country, as different regions harvest at slightly different times. Currently, many of these workers are from Nicaragua as it is the weakest economy in the region. Finding people to harvest coffee is likely to continue to be a challenge, and in fact at one stage Puerto Rico was using its prisoners to harvest coffee.

  SORTING THE BEANS

  After picking, the cherries are often sorted using a variety of different methods to prevent unripe or overripe coffee from joining the bulk of the lot. In parts of the world with relatively low labour costs, and little money available for investment in equipment, this is done by hand.

  In more developed countries, the cherries are often sorted using a flotation tank. The cherries are poured into a large tank of water, where the ripe fruit sinks to the bottom. They are pumped from there into the main processing section. Unripe fruit floats to the top and is skimmed off to be processed separately.

  Where labour costs are low, cherries are picked by hand to maximize the harvest of ripe fruit.

  A worker in El Salvador sorts hand-picked fruit.

  Cherry harvests are processed at a wet mill, where beans are separated from the parchment and then dried, ready for storage and shipping.

  PROCESSING

  How a coffee is processed after harvest can have a dramatic effect on the resulting cup, so it has become an increasingly important part of how it is described and sold. It would be a mistake to believe that coffee producers have flavour in mind when they choose their processing methods. A very small percentage do, but for most producers the goal is to ensure the processing causes the least possible incidence of ‘defect’ and causes no drop in the quality, and thus the monetary value, of the coffee.

  A fter harvest, the coffee cherries are taken to a wet mill to separate the beans from the flesh and dry the beans so they are safe for storage. Coffee beans start with a moisture content of around 60 per cent, and should be dried to around 11–12 per cent to ensure they do not rot while waiting to be sold and shipped. A wet mill can be anything from a small collection of equipment on an individual farm, to a very large industrialized facility for processing enormous amounts of coffee.

  The wet mill processes coffee from the cherry stage to the parchment stage, when the bean is dry but still covered with its layer of parchment or pergamino. Most believe that the coffee is pretty well protected by this outer layer, and that it does not really begin to degrade until the coffee is hulled to remove the parchment at the last possible moment before the coffee ships.

  The term ‘wet milling’ is slightly misleading as some producers use very little, if any, water in the processing methods they use. It does, however, make the distinction between this initial processing and the later stage when the hulling and grading takes place, known as ‘dry milling’.

  There is no doubt that processing can have a massive impact on the cup quality of the coffee, and there is a growing trend for skilled producers to manipulate the process in order to yield specific qualities in the cup. However, these producers are very rare on the global production scale.

  The goal of processing for most is to make the coffee as profitable as possible and this is taken into account when a producer chooses which processing method to use. Some processes require more time, investment or natural resources than others, and so it is an important decision for any coffee producer.

  DEFINING ‘DEFECT’

  The term ‘defect’ is used quite specifically in coffee. It is used to describe individual beans that have developed problems that result in bad flavours. Some defects can be spotted by taking a look at the raw coffee, while others only come to lig
ht when the coffee is tasted.

  A mild defect might be a bean that has been damaged by insects, and this is easy to spot. A more serious problem is a phenolic coffee, where the coffee has a very harsh, metallic, paint-stripper flavour, mixed with notes of sulphur (it is as bad as it sounds). The cause of this defect isn’t well understood yet. Bad processing can also cause defects, including giving the coffee a fermented flavour and an unpleasantly dirty, almost boozy quality. It can also add a taste reminiscent of barnyards and rotten fruit.

  THE NATURAL PROCESS

  Also known as the dry process, this is the oldest method of processing coffee. After harvest, the coffee cherries are spread out in a thin layer to dry in the sun. Some producers spread them out on brick patios, others use special raised drying tables, which allow a better airflow around the cherry, resulting in more even drying. The cherries must be turned regularly to avoid mould, fermentation or rotting taking place. Once the coffee is properly dry, the outer husk of skin and dried fruit are removed mechanically, and the raw coffee is then stored before export.