The Curious Barista's Guide to Coffee

by Tristan Stephenson

  This list (with the exception of geisha) makes little reference to the numerous wild heirloom varieties of Ethiopia, which are natural crossbreeds between different indigenous varieties. Some of these may involve other indigenous coffee species too (known as interspecific hybrids), which makes for a more diverse gene pool – a fact that is reflected in the character of Ethiopian coffee.

  BOURBON

  The original typica mutation from Réunion (Bourbon) Island, bourbon is the father and grandfather of numerous other popular Latin American varieties, including caturra, catuai, pacas and mundo novo. Bourbon is still popular in Latin America today, and has also travelled back to Africa, where it is grown in Rwanda and Burundi. Most bourbon varieties produce red ripe fruit, but there are yellow and orange variations, too. Bourbon is around 20–30 per cent higher-yielding than typica and produces coffee of a similar, albeit slightly sweeter and sometimes better balanced style.

  CATIMOR

  Not to be confused with caturra or catuai, catimor is a hybrid of caturra and timor. It is a highly disease-resistant strain that was planted widely in Latin America during the 1980s for its ability to fend off coffee leaf rust. Regrettably, though, it lacks the finesse of other arabica cultivars. This is accounted for by the timor variety (also known as arabusta), which is a natural hybrid between arabica (typica) and robusta; the robusta element explains the plant’s resilience against disease.

  CATUAI

  A hybrid of caturra and mundo novo, catuai is a highly disease-resistant, high-yield variety that was developed in Brazil in the 1950s. Just like caturra, ripe catuai cherries can have either red or yellow pigmentation (I prefer the former). Catuai is known for its bold acidity and is a popular variety across most of Central America.

  CATURRA

  This mutation of bourbon was found near the town of Caturra, in Brazil, in the 1930s. Caturra is a higher-yielding, more compact plant that makes for easy picking, but can become its own worst enemy in lower-altitude growing conditions, where the coffee becomes quite light-bodied and the weight of fruit alone can kill the plant. When grown at higher altitudes (above 1,200 m/4,000 ft), caturra plants produce both a better-quality coffee and a more sensible yield size. Caturra is a common variety in the Central American belt.

  GEISHA

  With its slightly elongated fruit and leaves, geisha is a mutation of typica that is believed to have originated from the south-west Ethiopian town of Gesha (both the spellings geisha and gesha are acceptable) In the 1930s some seeds were sent to Tanzania, and from there on to Costa Rica in the 1950s. Those two countries remain the only significant cultivators of geisha outside Panama – the country with which it is best associated.

  In high-altitude regions of Panama, geisha has proved to be the undisputed queen of varieties, producing coffee with tropical, citrus and tea characteristics. For this reason, we can expect in the future to see many more examples of geisha filling bags of coffee from other countries.

  MARAGOGYPE

  This variety is considered to be a natural mutation from typica. It was first discovered near Maragogipe (with an ‘i’) in Brazil's Bahia region. Maragogype is well known for producing very large beans and makes up half of the pacamara variety.

  MUNDO NOVO

  A bourbon and typica hybrid discovered in the 1940s that remains quite popular in Latin America today. It is more disease resistant and better yielding than bourbon and typica, but at the sacrifice of some complexity of flavour.

  PACAMARA

  One of the more sought-after varieties, pacamara is a hybrid of pacas and maragogype that was created in El Salvador in the late 1950s. Just like maragogype, it lacks in yield what it makes up for in bean size; its beans are regularly twice the size of a standard bourbon seed. Pacamara is highly prized for its quality, showing nice, clean acidity and floral characteristics, especially when grown at higher altitudes.

  PACAS

  A natural mutation of bourbon, discovered in El Salvador in 1949, pacas is a compact plant that can withstand relatively low elevation conditions, which is why it was chosen to breed with the contrasting maragogype variety.

  Yellow bourbon lives up to its name, displaying bright yellow, ripe fruit.

  TEKISIC

  Also known as ‘improved bourbon’, tekisic is a dwarf variety that was the result of 28 years of ongoing unnatural selection of bourbon plants conducted by the Salvadoran Institute for Coffee Research (ISIC) between 1949 and 1977. The lengthy process culminated in a relatively low-yield variety that was capable of producing some stunningly complex coffees with a big mouthfeel to back them up. As such, it has been welcomed by some El Salvadorian, Honduran and Guatemalan farms which are striving to improve the quality of their coffee.

  SL–28

  The ‘SL’ in SL–28 stands for Scott Laboratories, the name of the technical firm that the Kenyan government employed in the 1930s to identify the native coffee varieties that were best suited for widespread cultivation. It’s SL–28 that is partly responsible for the intense blackcurrant character that defines Kenyan coffees from some regions. SL–28 performs best at high altitudes.

  SL–34

  This variety is the slightly inferior (but by no means bad) sister of SL–28, which also possesses some striking acidity and berry-fruit qualities. SL–34 does a better job than its numerically lower sister at lower elevations, and is resistant to high rainfall at high altitudes, so certainly has its uses. Like SL–28, it is a variety that is quite susceptible to coffee leaf rust.

  VILLA SARCHI

  This dwarf variety is a bourbon mutation, discovered in Costa Rican town of Sarchi. Branches form at a steep angle from the tree’s body and can produce interesting bronze-coloured leaves among the normal green ones. Even more interesting is the excellent fruity coffee that the variety produces, with the added bonus of high yields and reasonable disease resistance.

  A Typica tree in Mexico with ripe coffee cherries ready for picking.

  COFFEE-BUYING GUIDE

  Just as a carrot or a cucumber deteriorates from the moment it is picked, the quality of a coffee bean diminishes from the time it was roasted. Knowing when your coffee was roasted is fundamental to understanding how fresh it is, so avoid buying bags that don’t have a roast date stamped on them. Pre-ground coffee should be avoided too, because, just like chopped vegetables, it spoils at a much faster rate. In recognition of this, many speciality coffee roasters no longer sell pre-ground coffee, but if you must buy pre-ground – the only acceptable excuse being that you are travelling without a grinder or your grinder is broken – it should be freshly roasted, ground and packaged in front of you, and consumed within 24 hours of grinding.

  Understanding how the coffee is intended to be brewed is the next important factor. Espresso coffee will generally be labelled as such, usually being of a darker roast and most of the time a blend of different coffees. The unforgiving nature of espresso brewing requires that the coffee flavour be carefully balanced to avoid the exaggeration of some of the coffee’s more wayward features in the finished cup. This is done with usually two or three component coffees, like a whisky blend, that cast a smooth crescent of fruity, earthy, bright, sweet, bitter, nutty, floral and roast characteristics. Single-origin espresso coffees are becoming more commonplace now, however, and these coffees are selected for their more placid nature.

  Coffees intended for brewing by a more traditional method tend to be lighter-roasted to accentuate acidity, and usually the product of a single country, co-operative or estate. Like a malt whisky, they are the product of a certain place, time and processing method and in general offer a more diverse range of coffee styles than that of an espresso blend.

  Lighter-roasted coffees can be brewed as espresso, but this tends to be done only with low-acidity beans. Darker-roasted coffees can be brewed in the traditional manner, but a higher-acidity coffee is usually required to attain the ‘brightness’ that we would hope to get from this type of brewer.

  I never like t
o keep an open bag of coffee for more than 3–5 days, no matter how well it has been stored. Buy regularly and in small quantities, or consider subscribing to a regular delivery from a roaster, which can be a fantastic route to the discovery of new and exciting coffees.

  A fresh bag of coffee, roasted in a style that will complement your chosen brewing method, will set you on the right path. Beyond this, there is a whole world of coffee origin, processing and varieties to explore. The only piece of advice that I will give you is to be as adventurous as possible and continue to challenge yourself with interesting coffees that stretch the boundaries of coffee style.

  KOPI LUWAK

  The legend of kopi luwak goes back to the 18th century, when the Dutch-controlled Indonesia. The native workers at the time were forbidden from harvesting and selling coffee for their own use, so they took to searching around for it on the forest floor. They found clumps of raw coffee seeds in the faeces of the luwak, a nocturnal civet cat, that had taken coffee cherries as its chief source of nutrition. This civet-poo coffee proved to be delicious once roasted, because the cat selected only the ripest cherries for its midnight snacks and because its digestive system did a fantastic job of stripping the mucilage off the beans.

  Jump forward 300 years and kopi luwak still commands a great deal of attention, mostly, it seems, for the novelty of paying a lot of money for something extracted from animal droppings. It should go without saying that, by the standards of today’s speciality coffee, kopi luwak coffee does not live up to its price tag, but there is also a far more sinister side to this story that needs to be told.

  The market value of kopi luwak is so high that some unscrupulous types have taken to caging these solitary animals in large groups and force-feeding them coffee cherries of all types, ripe, underripe and overripe. There are also many fake versions available. Please avoid kopi luwak altogether and spend your money on some genuinely good coffee that didn’t have to pass through a caged animal to get to you.

  GLOSSARY

  AA Green bean grading that is commonly used in Africa. AA beans will pass through a Grade 18 (18/64-inch diameter) sieve perforation, but not a Grade 16, and are among the largest beans. Roughly equivalent to a Superior or Supremo.

  Altura Meaning ‘height’ in Spanish and sometimes used to indicate coffee grown at altitude.

  Arabica (coffea arabica) The most widely grown coffee species on the planet.

  Aromatic (compound) A chemical mixture that contributes to the aroma of coffee.

  Bloom The process of pouring a small amount of water over ground coffee – usually in pour-over/percolation brews – to kick off the extraction. Named after the manner in which the coffee swells as the water penetrates it.

  Brew ratio The ratio of brew water to coffee (in grams) that is used in coffee brewing (e.g., 15:1, where 15 times the weight of water is used to coffee weight).

  Brew time The total length of time that coffee is in contact with water during brewing.

  Burr (grinder) One of the serrated cutting discs used in a burr grinder. The distance between the discs can be adjusted to achieve the desired grind size.

  Carrageenan A thickening or gelling agent extracted from red seaweed (Irish moss).

  Caramelization A reaction involving sugars that occurs during coffee roasting. A caramelized sugar is less sweet but has greater complexity of flavour and aroma.

  Cinnamon roast A very light (cinnamon-coloured) roast dropped on or very shortly after first crack.

  City roast A medium roast somewhere between first crack and second crack.

  Co-operative (co-op) A group of farms that share resources and infrastructure.

  Crack An audible cracking or snapping sound during roasting in two distinct phases of the roast.

  Cultivar A portmanteau of the words ‘cultivated’ and ‘variety’; used in references to a coffee variety that has been cultivated for commercial production.

  Cup of excellence An annual evaluation programme held in several different countries that aims to source, evaluate and score top-quality coffee, then sell the winning coffees by auction.

  Cupping A systematic method of tasting and assessing a selection of different coffees.

  Dry mill A place where parchment coffee is hulled, sorted, graded and packed for shipping.

  Dry process(ing) After harvest, the whole intact coffee cherry is dried before being hulled to remove the green coffee bean.

  Excelso Green-bean grading that is used in South America and particularly Colombia. Excelso beans will pass through a Grade 16 (18/64-inch diameter) sieve perforation, but are too large to fit through a Grade 14.

  Extraction The capture of soluble material from ground coffee into water during brewing.

  First crack The audible popping or snapping noise that emanates from the beans during roasting, and after which the coffee can be considered ‘roasted’.

  French roast A very dark roast that has passed second crack.

  Full city roast A roast that is quite dark; just on the cusp of second crack.

  Giling basah A coffee-processing method commonly seen in Indonesia. In this process the coffee is hulled from its parchment before it has been fully dried; this is followed by a drying phase. The result is a full-bodied, quite earthy coffee.

  GrainPro A multi-layered plastic bag with a gas barrier used for transporting green coffee. The bags have been shown to extend the flavour life of the coffee significantly over storage in jute or burlap bags.

  Green coffee The dried and processed seed of the coffee fruit in its unroasted form. Named for its typically green colour.

  Heirloom (varieties) A traditional variety of coffee that is indigenous to, or has been grown in, a specific region for a very long time.

  Honey process see Pulped natural.

  Hulling The final step before storing at the dry mill where the green coffee bean is removed from the parchment shell.

  Hybrid A natural or artificial cross-breed of two different varieties or species of coffee plant.

  Leaf rust A rust-coloured fungus that attacks the leaves of coffee trees and eventually kills them.

  Lot The specially selected batch of green coffee of a specific size.

  Maillard reaction An important reaction in coffee roasting that gives coffee its brown colour and many of its associated flavours.

  Micro-lot A small selection (typically ten 60 kg/ 120 lb bags or less) from a specific farm or co-op.

  Moka/Mokha/Mocha Moka (pot) is a stove-top coffee-maker that produces a strong drink using steam-powered percolation. Mokha is the Yemeni trading port through which, at one time, nearly all the world’s coffee passed. Mocha (mochaccino) is a cross between a cappuccino and a hot chocolate.

  Monsoon(ing) A traditional method of ageing green coffee in India where the coffee is exposed to wet conditions for approximately three months, resulting in a loss of acidity.

  Mucilage The sticky layer of fruity material that surrounds the unprocessed coffee bean.

  Mutation A coffee plant that is a descended from another single-variety plant, but shows a marked deviation in terms of height, leaf shape, disease resistance, etc.

  Overextraction The capture of too much soluble material during coffee brewing, resulting in a cup that is bitter, astringent, harsh and flat. The cause is usually an overlong brew time or too fine a grind.

  Parchment (coffee) The protective shell that still surrounds a green coffee bean after the wet-milling process. The parchment is removed at a dry mill before sorting.

  Peaberry A single (typically rounder) coffee seed that forms in a cherry in the place of two.

  Percolate The gradual filtration of water through coffee.

  Portafilter The handled part of an espresso machine that holds the filter basket, into which ground coffee is placed.

  Pre-infusion The initial low-pressure burst of water applied by an espresso machine before proper high-pressure extraction ensues.

  Process(ed) A general term that refers to the remova
l and/or drying of the skin and fruit of the coffee cherry.

  Pulped natural After harvest, the coffee beans are squeezed from the cherry then dried on patios or raised beds with their mucilage intact.

  Second crack An audible popping or snapping noise that emanates from the beas during the later stages of a dark roast.

  Semi-washed see Pulped natural.

  Silverskin The very fine papery layer of material found on green coffee.

  Single origin An ambiguous term that generally refers to a coffee that is not blended and may come from a single country, region, co-operative or estate.

  Supremo Green-bean grading that is used in South America. Supremo beans will pass through a Grade 18 (18/64-inch diameter) sieve perforation and are the next size up from an Excelso. Roughly equivalent to a Superior or AA.

  Strictly high grown (SHG) An indication that the coffee has typically been grown at an altitude above 1,000 m/3,200 ft, which correlates to higher-density (better-quality) coffee.

  Tamping A process in espresso brewing where the ground coffee is levelled and compacted in the portafilter basket using a tamper, for an even extraction.

  Terroir The environment in which the coffee is grown, including such factors as soil, topography and climate.

  Underextraction This is the capturing of too little soluble material during coffee brewing, resulting in a cup that is sharp, sour and weak. The cause is usually too short a brew time or too coarse a grind.

  Vienna roast A roast that is dumped at around second crack. This is a dark roast where most of the character of the green coffee will have been lost.

  Washed process After harvest, the coffee beans are squeezed out of the cherry, then their sticky mucilage is broken down through an enzymatic process. The mucilage is then washed off and the bean is dried on patios or raised beds.

  Wet mill A station or facility that processes coffee cherries into dry parchment coffee.

  Wet process see Washed process.

  Xanthan gum A thickening agent secreted by the bacterium Xanthomonas campestris.