The Glossary

"C" Market

The commodities exchange in New York where coffee futures are bought and sold. This price is considered the base price for coffee trading.[5]

Acidity

Typically seen in high-altitude coffees, acidity is a pleasing piquant quality that gives liveliness to the cup. Acidity levels can vary in different coffees.[5]

Acidity

The sharpness, snap, sourness, or liveliness of coffee.[2]

Afterburner

A device attached to a coffee roaster used to filter exhaust air at very high heat (600°C+) that eliminates smoke, odour and particulates.[5]

Aftertaste

(aka finish). The lingering flavour impression of a coffee on your palate.[5]

Agtron Scale

The measuring system used to estimate the degree of roast using a numbering system scale as measured using an AGTRON READER.[5]

Alkaline

A solution with a pH greater than 7.0.[2]

Alkalinity

A solution's ability to buffer acids.[2]

Alkaloid

Any of a class of nitrogenous organic compounds of plant origin that have pronounced physiological actions on humans.[5]

Arabica

Short for coffea arabica, the most widely grown species of the coffee plant. It is considered superior to robusta, the other species commonly grown.[1]

Arabica

One of two commercially grown species of coffee (see also Robusta). Arabica is the higher quality species of the two.[4]

Arabica

(aka Coffea Arabica). The most widely planted commercial coffee species. Considered to be of the highest quality.[5]

Aroma

A quality that can be detected by the olfactory system.[2]

Aroma

The distinctive, usually pleasant, smell of a brewed coffee.[5]

Aromatic Compound

A chemical compound within coffee that contributes to the aroma of the coffee when ground or brewed.[1]

Astringent

Classified more in relation to its effect on the tongue than its actual taste. It creates a puckering sensation in the mouth or a dry, chalky feeling.[5]

Baggy

A smell or off-taste in coffee similar to that of a burlap/hessian coffee bag.[5]

Baked

A roast defect that results in a cereal-like flavour and reduces the coffee's sweetness. Usually experienced in coffee roasted too slowly or at too low a temperature.[5]

Balanced

When you have a pleasing combination of two or more key taste sensations.[5]

Batch

A quantity of coffee roasted in each roast cycle.[5]

Bean Temperature

The external temperature of the coffee, used to control the temperature of the roaster during the roasting process.[5]

Beneficios

A Spanish word for a processing mill (either wet or dry).[4]

Bimodal

Having two modes, or values, that occur most frequently.[2]

Bitter

A strong, unpleasant taste detected on the back of the tongue. Moderate bitterness balanced with sweetness in the cup is a good thing.[5]

Black

A physical defect in green beans where 50% or more of the external bean is black in colour, usually due to extended fermentation or an infection during the bean's development.[5]

Blend

The process of mixing two or more coffees of differing growing regions/farms, varieties, processing methods and roast levels to create a new drinking coffee.[5]

Bloom

Pouring a small amount of water on to the coffee at the start of a pour-over brew in order to start the extraction process is called the ‘bloom’ because of the way the coffee swells when it gets wet.[1]

Body

(aka mouthfeel). A spectrum of how big and heavy a coffee feels in your mouth.[5]

Body

A beverage's weight or fullness as perceived in the mouth.[2]

Bottomless portafilter

A portafilter with its undercarriage shaved off to allow viewing of the bottom of the basket during extraction.[2]

Bourbon

A botanical variety of Arabica coffee known for its sweet and distinct cup profile.[5]

Brew colloids

Materials smaller than one micron in any dimension that are dispersed in a coffee. Made up of a combination of oils and cell wall fragments.[2]

Brew ratio

The ratio of dry grounds to water used to make a coffee.[2]

Brew Ratio

The relationship between the amount of ground coffee used and the amount of water used to brew it.[1]

Brew strength

The concentration of solids (or solubles) in an espresso (or coffee).[2]

Brew Time

The total amount of time water is in contact with coffee when it is being brewed.[1]

Burlap

(aka hessian). This is the jute fibre material used in the traditional bag that green coffee is packed and shipped in.[5]

Burr Grinder

A coffee grinder that has two sharp cutting discs, usually metal, that can be adjusted to grind coffee to the desired grind size.[1]

Burrs

Discs in grinders that crush coffee beans into particle sizes for brewing or espresso.[4]

Buttery

A full and rich coffee flavour with an oily texture/body in the mouth.[5]

Bypass valve

A channel used to divert a predetermined proportion of the brewing water around the grounds during drip brewing.[2]

C-Price

The price of commodity coffee traded on the stock market. This price is considered the base price for coffee trading.[1]

Café crema

A very long pull of espresso.[2]

Caffeine

The stimulating, bitter alkaloid that coffee is famous for.[5]

Caffeine

A chemical found in coffee that contributes to feelings of alertness.[4]

Caramelisation

Sugar-browning reactions in the coffee roasting process. Similar to cooked/brown sugar, it can be a desirable flavour in roasted coffee if managed during the roasting process.[5]

Certification

Guidelines set to a specific set of social or environmental guidelines. These guidelines may cover where and how a coffee is grown, harvested or processed. There are numerous certification bodies.[5]

Chaff

The thin layer of skin that covers a roasted coffee bean.[4]

Chaff

(aka silverskin). The thick skin that's left on the coffee bean/seed after processing and which comes off as the beans expand during roasting.[5]

Channel

An area of high-velocity flow through a coffee bed.[2]

Charge

The act of loading the green beans into the roasting chamber of your coffee roaster.[5]

Charge Temperature

The air temperature of the empty roaster before loading your batch of green beans into the roaster.[5]

Cherry

The fruit where the coffee seeds (beans) live. Will usually have two seeds or one peaberry.[5]

Cherry

The fruit of the coffee tree is often called a cherry, or berry. The two seeds inside the cherry are the coffee beans.[1]

Cinnamon Roast

A very light roast level that occurs at the start of the First Crack. In tasting terminology this refers to a flavour nuance in light roasts and a particular spice-like aroma.[5]

City Roast

A light-to-medium roast level.[5]

Clean

A coffee free of taints and faults.[5]

Cocoa

An aroma generally associated with stale coffee.[5]

Coffee Berry Borer

A pest that afflicts the coffee crop, burrowing into the fruit and consuming the beans inside.[1]

Coffee Cherry

The fruit of the coffee tree. It is surrounded by a skin, and contains mucilage, parchment, and, usually, two coffee seeds.[4]

Cold-Brewed Coffee

Coffee that is prepared with a dripper tower and cold water, or a hot brew that is allowed to cool.[4]

Commodity Coffee

Coffee that has no value linked to its quality, and whose traceability is neither important nor often available.[1]

Commodity Market

The coffee trade market in New York, Brazil, London, Singapore, and Tokyo.[4]

Compact layer

A densely packed solid mass that can form at the bottom of the coffee bed during espresso percolation.[2]

Complex

A term that describes the balance and intensity between a coffee's flavour and characteristics.[5]

Concentration gradient

The difference in concentration of coffee solids from within the grounds to the surrounding liquid.[2]

Conduction

The flow of internal energy (heat) from a region of higher temperature to one of lower temperature.[5]

Contact time (dwell time)

The amount of time the grounds and brewing water are in contact.[2]

Continuous Roaster

A high-yield roaster that roasts coffee continuously rather than in batches.[5]

Convection

When a fluid, such as air, is heated and then travels away from the source, it carries the thermal energy along with it.[5]

Cooperative

A group of farmers working together for their mutual benefit.[1]

Crema

The layer of brown foam that appears on top of an espresso, caused by the drink being brewed under high pressure.[1]

Crema

Espresso foam composed primarily of CO₂ and water vapor bubbles, with tiny liquid films made up of an aqueous solution of surfactants. Also contains dissolved CO₂, sugars, gases and solids, emulsified oils, and suspended coffee bean cell wall fragments.[2]

Crema

The layer of foam that forms on top of an espresso.[4]

Creosote

(aka hydrocarbon residue). The organic compounds deposited in the exhaust ducting of the coffee roaster. Highly flammable and slow burning.[5]

Cultivar

A cultivated variety (see also Variety) intentionally bred for consumption.[4]

Cup of Excellence Competition

A programme established to find, evaluate and rank fine-quality coffee from a particular country, and then sell the winning coffees through an international online auction system.[1]

Cup Quality

The combination of the positive taste and flavour attributes of a particular coffee.[1]

Cupping

A standardized procedure for evaluating roasted and ground coffee.[2]

Cupping

A sensory evaluation of coffee for flavour and aroma profiling that should follow a systematic procedure.[5]

Cupping

The practice of tasting and evaluating coffees.[4]

Cupping

The process of brewing, smelling and tasting coffee used by professional tasters in the coffee industry.[1]

Current Crop

Green coffee beans from the most recently available harvest.[5]

Dark Roast

Coffee roasted for a longer time, until the bean is a dark brown, with an oily surface.[1]

Data Logger/Logging

Equipment used to record time and temperature data during the roasting process in order to assist the master roaster in profile roasting.[5]

De-gassing

The practice of leaving beans to release gases created during the roasting process.[4]

Deadband

The difference between the actuation and deactuation points of a pressure-stat.[2]

Decaffeination

The complex process of removing caffeine from green coffee beans.[5]

Defect

A flaw in the coffee bean that contributes an unpleasant taste.[1]

Defects

Faults detected in green beans. Commonly caused by problems during picking, processing, drying, sorting, storage and transportation.[5]

Degassing

When coffee releases CO2 naturally after being recently roasted.[5]

Degassing (outgassing)

The release of gases, particularly CO₂, by roasted coffee beans.[2]

Demitasse

A "half cup" — typically referring to a 90ml (3oz) espresso cup with a handle.[4]

Demucilage

(aka water process, wet process). Process where the fruit pulp (aka mucilage) is removed from coffee beans by scrubbing in machines.[5]

Development

A measure of the degree of breakdown of the coffee bean's cellulose structure during the roasting process.[5]

Dialling In

The process of adjusting an espresso grinder until the resulting coffee tastes good and is properly extracted.[1]

Diffusion

The movement of a fluid from an area of higher concentration to an area of lower concentration.[2]

Dirty

An undesirable flavour in coffee cupping that can imply that a defect is present.[5]

Dose

A measure of coffee intended for brewing with water.[4]

Double Drum

(aka double walled, double barrel). A coffee roaster where the drum is made of two layers of steel separated by a small gap in between.[5]

Double Roasting

A process where a batch of coffee is roasted to the yellow stage, allowed to cool, and then roasted again to the desired final level.[5]

Draw

The natural draw of air created by chimney stack/flue that draws smoke out.[5]

Drop

To release the roasted coffee from your drum barrel into the cooling tray.[5]

Drum Roaster

A type of coffee roaster where batches of coffee beans are continuously tumbled as they roast in a rotating cylindrical steel drum.[5]

Dry Mill

A facility that will hull, sort and grade parchment coffee, ready for export.[1]

Dry Mill

Facility where coffee is hulled, sorted and graded.[5]

Dry Process

A post-harvest process in which the whole coffee cherry is dried before being hulled to extract the green coffee inside.[1]

Earthy

Considered a taint in washed coffees and in some dry process coffees. Reveals a mustiness picked up by coffee sometimes when dried on the ground.[5]

Emissions Control

The control of emissions through the use of afterburners in accordance with smoke and odour regulations.[5]

Emulsion

A suspension of small globules of oil in an espresso in which the oil and liquid are immiscible.[2]

Endothermic

A process that requires or absorbs energy from its surroundings, usually in the form of heat.[5]

Environmental Temperature (EV)

The air temperature of the roaster.[5]

Espresso brewing ratio

The ratio of the mass of a dry dose of espresso grounds to the mass of the shot produced by the grounds.[2]

Ethyl Acetate

A chemical used in the decaffeination process.[5]

Exothermic

A chemical reaction that releases energy through light or heat. It is the opposite of an endothermic reaction.[5]

Extraction

A process that occurs during brewing, when coffee solubles dissolve into water.[4]

Extraction

The removal of mass from coffee grounds.[2]

Extraction

The process of dissolving soluble flavours from coffee grounds in water.[5]

Extraction

The process of brewing coffee in which a percentage of the ground coffee is dissolved in the water.[1]

Fair Trade

Certification by organisations that guarantee that minimum wages and environmental conditions have been met.[5]

Fair Trade Movement

A group of organizations looking to certify and reward cooperatives of coffee producers, with a guaranteed premium and minimum price for their coffee.[1]

Fast Roast

The commercial technique of roasting coffee very quickly, often in less than five minutes, as part of the process of making instant/soluble coffee.[1]

Ferment

Microbial green coffee defect that gives an acrid or sour taste and smell.[5]

Fermentation

A part of the wet process method where natural enzymes loosen the pulp as the skinned beans soak in water tanks.[5]

Fines

Tiny coffee bean cell wall fragments produced by grinding.[2]

Fines migration

The transport of fines by the brewing liquid as it percolates through a coffee bed.[2]

Finger-strike dosing

A method of grooming a dose of espresso grounds by swiping a straightened finger across the surface of the dose.[2]

First Crack

Characterised by loud popping noises and is a significant phase in the roasting process. When pressure and water vapour are released from the inner coffee beans as a result of complex chemical reactions inside the bean.[5]

Flat

See Stale.[5]

Flavor

The combined sensation of a substance's taste and aroma.[2]

Flavour Profile

The total impression of the coffee. The sum of aroma, acidity, body, sweetness and aftertaste.[5]

Floater

Green bean defect. Characterised by fermented, bitter or straw-like flavours.[5]

Fluid Bed Roaster

(aka air roaster). A coffee roaster that uses hot air to agitate and roast coffee simultaneously.[5]

French Roast

Very dark-roasted coffee, oily surface. Characterised by dark and pungent, smokey flavours.[5]

Fruity

Can be a flavour taint in line with fermented taint. However, mostly used to describe a citrus/berry sweetness in certain coffees.[5]

Full (City) Roast

US term for a[5]

Fully Washed

A post-harvest process in which the coffee beans are squeezed from the fruit, fermented and washed clean before being dried.[1]

Geisha

A popular Arabica wild coffee that has been achieving remarkably high prices at auction.[5]

Gicleur

A small orifice that limits water flow to the group head in an espresso machine.[2]

Giling Basah

A post-harvest process common in Indonesia, in which the coffee is hulled from its parchment layer while still at high moisture levels and then dried. This contributes a particular earthy quality to the coffee’s flavour. See also semi-washed process.[1]

GrainPro

Hermetically sealed bags used for the storage of green coffee beans.[5]

Grassy

A herbal-like flavour taint found in green coffee not dried properly in processing, as well as in under-roasted coffee.[5]

Green Beans

Raw, unroasted coffee beans.[4]

Green Coffee

Unroasted raw processed green coffee beans. The form in which coffee is internationally traded.[5]

Green Coffee

The coffee industry term for raw, unroasted coffee. This is the state in which coffee is traded internationally.[1]

Grind Size

The size of the particles of ground coffee. The finer and smaller the pieces, the easier it is to extract flavour from the coffee.[1]

Grooming

The leveling and refining of a dose of espresso grounds.[2]

Hard Bean

See Strictly Hard Bean (SHB).[5]

Hardness

A measure of calcium and magnesium ions dissolved in water.[2]

Heat exchanger

A small pipe within an espresso machine boiler where water is flash-heated on its way to the group head.[2]

Heirloom Varieties

A term used for varieties of coffee that have been traditionally grown for some time.[1]

Heirloom Variety

Coffee that is genetically closer to the wild varieties of Arabica coffees.[5]

Honey Process

(aka miel process). Similar to the pulped natural process, the coffee is pulped but a good amount of the fruit flesh is left on during the drying phase.[5]

Honey Process

A post-harvest process, similar to the pulped natural process, in which the coffee bean is squeezed from the fruit but a variable amount of fruit flesh is left on during the drying phase.[1]

Hulling

The process of removing the parchment and silverskin on washed coffees prior to the milling process.[5]

Hybrid

A cross between two species of coffee.[4]

Imperfections

Physical defects present in green beans such as shells, quakers and broken beans. Green coffee is graded according to a limited number of the imperfections being present.[5]

In Reposo

Also known as ‘resting’, this describes the period of time when raw coffee is stored in parchment before it is hulled, graded and exported. This process is considered important in stabilizing the moisture content within the bean.[1]

Infusion

A solution produced by steeping in water.[2]

Insoluble

Cannot dissolve in water.[2]

International Coffee Agreement

A quota system in place between many coffee-producing countries and importers to prevent supply and demand swings and keep prices relatively stable.[5]

International Coffee Agreement

First signed in 1962, this is a quota system in place between many coffee-producing countries and some importing countries in order to prevent supply and demand swings on the global market and stabilize pricing.[1]

Italian Roast

A dark roast often taken into the Second Crack and displays some oil on the surface.[5]

Latte Art

The patterns created by carefully pouring foamed milk into espresso coffee.[1]

Leaf Rust

A disease spread by spores on the underside of the plant. Originally found in Brazil it is now present in many coffee-growing countries.[5]

Leaf Rust

An orange/brown fungus that attacks the leaves on a coffee tree, eventually causing the tree to die.[1]

Light Roast

A roast level that preserves a coffee's acidity and fruitier flavours. In roasting terms it is a coffee where the beans are dropped before, or just after, the end of the First Crack.[5]

Light Roast

A coffee roasted in such a way as to preserve its acidity and fruitier flavours. The term refers to the coffee bean being a lighter shade of brown.[1]

Lot

A distinct quantity of coffee, which has gone through some standard processing.[1]

Lungo

A "long" shot of espresso. When defined by mass and brewing ratio: a shot weighing approximately three times the mass of the dose of dry grounds used to produce it.[2]

Machine Dried

A coffee that has been dried mechanically.[5]

Maillard Reaction

A browning reaction between amino acids and reducing sugars. Also contributes to a coffee's "roasty" flavour.[5]

Maragogype

(aka Maragogipe, Elephant Bean). An Arabica coffee characterised by its large size and low yield.[5]

Medicinal

A flavour taint found in coffee described as chemical or astringent.[5]

Medium Roast

When a coffee is dropped during the roasting process right on, or just before, the Second Crack.[5]

Mel (Process)

See honey process.[1]

Methylene Chloride

A chemical that is colourless used in the decaffeination of green coffee beans.[5]

Micro-Lot

Typically a volume of 10 x 60kg/132lb bags or less, of a green bean selection from one producer or farm.[5]

Micro-Lot

A small selection from one producer group, typically ten bags (each weighing 60 or 62kg) or fewer of a particular lot.[1]

Milling

The mechanical removal of the dried fruit husk from a dry-process green coffee bean or the dry parchment skin from a wet-process bean.[5]

Monsoon Coffee

The practice along India's south-west Malabar Coast, where harvested beans having been processed to the 'green' coffee state, are then subjected to a lengthy period of exposure to the humid sea air in order to increase the body and reduce their acidity.[5]

Monsooning

A post-harvest process in which harvested coffee is exposed to the monsoon-season winds and rains, causing the coffee to lose its acidity.[1]

Mouldy

Caused usually by damp storage conditions, this is a flavour or visual defect in coffee beans.[5]

Mouthfeel

(aka body). The tactile attributes of how the coffee feels in your mouth when drinking it.[5]

Mouthfeel

A term used to describe the texture and tactile attributes of the coffee when drinking it, ranging from very light to viscous.[1]

Mouthfeel

The in-mouth tactile sensations produced by a beverage.[2]

Mucilage

See Pulp.[5]

Mucilage

The sticky, sweet fruit meat or pulp surrounding the parchment-covered coffee seeds inside a coffee cherry.[4]

Natural Process

The drying of picked ripe coffee beans in the sun until the entire cherry is dry. The dried cherry is then milled to remove the coffee beans. This process can result in a complex and fruity flavour profile.[5]

Natural Process

The practice of processing coffee cherries by leaving them out to dry in the sun.[4]

New Crop

(aka current crop). Processed green coffee from the most recent harvest.[5]

Normale

A "standard" shot of espresso. When defined by mass and brewing ratio: a shot weighing approximately twice the mass of the dose of dry grounds used to produce it.[2]

Oily

Seen in dark roasts, this term describes the surface of the coffee bean after a deep roast.[5]

Old Crop

Green coffee from the latter half of the harvest year.[5]

Organic

A third-party certified coffee that has been grown and processed without the use of pesticides or herbicide chemicals.[5]

Organic Acid

An organic acid is an organic compound with acidic properties.[5]

Overextraction

This refers to extracting more of the soluble material, producing a bitter, harsh and unpleasant cup.[1]

Overextraction

The removal of more than the desired amount of mass from the grounds when making a coffee or tea.[2]

Parchment

A thin paper skin surrounding wet process coffee beans after they have been de-pulped and dried.[5]

PID controller

Proportional integral derivative controller. Installed in an espresso machine to improve brewing water temperature consistency.[2]

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