Acetic Acid

Organic acid that can be found in coffee. In small amounts, it contributes wine-like acidity to coffee but results in more vinegar-like sourness in larger quantities.

Acidity

The perception of acid or ‘sourness’ in brewed coffee. All coffees contain naturally occurring acids, this is a major contributor to the liveliness and complexity of coffee. Roasting coffee lighter enhances acidity in brewed coffee while darker roasted coffee results in the breakdown of acids and lower perceived acidity.

Aftertaste

Also known as the finish, this is the taste and aroma left by the coffee after swallowing.

Altitude

Often described in meters above sea level (MASL), this refers to the height at which coffee is grown. Higher altitudes typically result in more refined acidity in brewed coffee.

Anaerobic Fermentation

An oxygen-free process where coffee is placed in a closed container to ferment, imparting a unique flavour to the coffee.

Aroma

The perception of the release of volatile aromatic compounds in roasted coffee. This can range from floral and fruity notes to smoky or more chocolatey notes depending on how the coffee was grown, processed, and roasted.

Barista

An Italian word for a person who works in a bar. In a cafe, this refers to the individual preparing coffee and other beverages.

Bitterness

There can be a lot of bitterness in coffee depending on how it is grown, processed, roasted, and brewed. When balanced with sweetness and acidity, it can add to the complexity of the coffee. However, when a coffee is over-roasted or over-extracted this can result in bitterness that can overwhelm other flavours.

Bloom

A part of the coffee brewing process, most commonly seen in pourover methods. This involves adding a small amount of hot water to ground coffee at the start of the brew. This promotes the release of Carbon Dioxide, resulting in the slurry expanding and bubbling and creating a golden-to-light brown foam.

Boiler

The part of the espresso machine that heats and stores water.

Boulders

Larger particles produced when grinding coffee.

Brew Ratio

The ratio between the amount of coffee and water used when brewing.

Brew Temperature

The temperature of the water used to brew coffee.

Burrs

The part of the grinder that grinds roasted coffee beans. The geometry of grinder burrs can have a big impact on the flavour of the resulting coffee.

Cafe Latte

A single shot of coffee with milk served in a latte glass with 1cm of froth.

Caffeine

A compound commonly found naturally in coffee, tea, and cacao that acts as a stimulant to the central nervous system.

Cappuccino

A single shot of coffee with milk served in a cappuccino cup with 2cm of froth.

Carbonic Maceration

A technique borrowed from the wine industry, it is a fermentation technique involving coffee being placed in tanks filled with carbon dioxide. This often imparts a confectionary-like flavour profile to the coffee.

Cascara

Tea made from the dried fruit of the coffee cherry.

Chaff

The dried silverskin of coffee that gets released during the roasting process.

Channelling

A phenomenon that occurs when water flows through a crack or weaker section instead of flowing evenly through a bed of ground coffee.

Chlorogenic Acid

The most prevalent acid in raw coffee - steadily breaks down into caffeic and quinic acid during the roasting process. Contributes to sourness and astringency when present in higher levels.

Citric Acid

Organic acid that can be found in coffee, imparts sourness and contributes citric fruit-like flavours to coffee.

Coffee Cherry

The coffee bean as we know it is the seed of a cherry-like fruit. Most coffee cherries contain two seeds for each fruit. From outside-in, the coffee cherry consists of the skin, pulp, mucilage, parchment, silverskin, and seed.

Crema

The golden brown layer of trapped gas (mostly Carbon Dioxide) that is often found on top of an espresso.

Cupping

A technique used to systematically evaluate the aroma and flavour of coffee. An example of an immersion brew method - this is how most coffee producers, wholesale buyers, and roasters assess the quality of coffee.

Decaf

Refers to coffee beans that have undergone a decaffeination process to remove the caffeine compound. The most common decaf process is the Swiss Mountain Process, which removes caffeine through diffusion by soaking coffee in a water-based solution.

Degassing

A process that occurs as roasted coffee ages. A large amount of Carbon Dioxide is produced when coffee is roasted, this is slowly released as coffee is allowed to rest.

Dose

The weight of dry, ground coffee.

Drawdown

The final period of pourover or percolated brewing. This begins after all water has been added to the brew.

Dual Boiler

A style of espresso machine that has two separate boilers. One supplying water to the group heads, the other supplying steam to the steam wand. This allows the user to set different temperatures for each boiler and brew espresso while steaming milk simultaneously.

Espresso

A shot of coffee created by forcing water through ground coffee.

Espresso Machine

A machine designed to push hot water through compressed ground coffee to create a thick and concentrated shot of brewed coffee.

Extraction

The process of soluble compounds in coffee being dissolved into water.

Filter Basket

A metal basket that holds coffee grounds. This is placed in the portafilter for espresso brewing.

Filter Coffee

A term used to describe most methods of brewing that does not involve an espresso machine. This commonly uses significantly more water resulting in a lower brew ratio. In specialty coffee, lighter roasted coffee is often used for this brewing method resulting in a lighter, more tea-like result.

Fines

Smaller, dust-like particles produced when grinding coffee.

First Crack

A phase during the coffee roasting process, signified through loud popping noises created by the beans from the release of gas and water vapour.

Flat White

A single shot of coffee with milk served in a cappuccino cup with 3mm of froth.

Froth

Trapped air in milk. This is what gives steamed milk its creamy texture and is an essential part of latte art.

Frozen Coffee

Vacuum-sealing and freezing drastically slows down the aging process of both roasted and green coffee. While it is resource and labour-intensive, it is a useful way to preserve coffee.

Grind

The particle size of the ground coffee.

Grinder

A piece of equipment used for grinding roasted coffee beans.

Group Head

The part of the espresso machine that dispenses hot pressurised water into the ground coffee and filter basket.

Honey Process

Also known as semi-washed or pulped natural. This involves removing the pulp and skin of the fruit of the coffee cherry but leaving the inner layer known as the mucilage intact before drying. This is somewhere between the natural and washed processing methods. No actual honey is involved.

Immersion

A style of brewing where ground coffee is completely immersed in water and steeped until the desired extraction is achieved. Common immersion brew methods include cupping, French press, Aeropress, and Syphon. This is also how tea is most commonly brewed.

Long Black / Americano

3cm of hot water in a cappuccino cup with a double shot of coffee. Water volumes will vary depending on each cafe. An Americano often has more water.

Long Macchiato

Double shot of coffee with a large dollop of milk froth. Sometimes with additional hot water.

Magic

Double ristretto, 3/4 full flat white.

Malic Acid

Organic acid that can be found in coffee. Contributes to clean apple-like flavour to coffee.

Mouthfeel

The sensation of coffee on your palate and in your mouth. Often used to describe the viscosity of the coffee. This can range from silky and smooth to thick and creamy depending on the coffee.

Natural Process

Also known as dry processing, this involves drying coffee cherries whole in the sun before removing the seed using mechanical methods.

Percolate

The process of poured/dripped water gradually moving through ground coffee. Common percolated brew methods include pourovers, batch brews, and Chemex.

Phosphoric Acid

Inorganic acid that can be found in coffee. Prevalent in Kenyan coffee, contributes to blackcurrant and blueberry flavours in coffee.

Piccolo

A single shot of coffee with milk served in a piccolo glass with 5mm of froth. Usually served with half the amount of milk compared to a Cafe Latte.

Portafilter

The assembly that holds the ground coffee. This includes the espresso filter basket and handle placed in the group head to produce espresso coffee.

Pourover

A method of brewing percolated filter coffee. This involves pouring hot water over coffee through a paper filter. Common pourover brewers include the Hario V60, Kono Dripper, Chemex, and the Kalita Wave.

Pre-Infusion

A process used in espresso brewing. This involves infusing a small amount of water through ground coffee before the full extraction process begins. Similar to the bloom process used in pourover coffee.

Pressure

An essential part of brewing espresso coffee. Pressure in an espresso machine is formed from a combination of the force of the water being released by the group head and the resistance provided by compressed ground coffee in the filter basket. Some espresso machines can vary the force of the water during a shot, creating ‘Pressure Profiles’. While most commercial espresso machines are set to produce a steady 9 bars of pressure during extraction.

Processing Method

This refers to how the raw and green coffee seed/bean is extracted from the coffee cherry and dried. There are three main traditional processing methods: Washed, Natural, and Honey Process.

Q Grader

A trained and licensed coffee taster who evaluates coffees based on criteria and methods determined by the Coffee Quality Institute and Specialty Coffee Association.

Refractometer

A tool to measure the TDS in a solution. It measures the level of light refraction in a solution to measure the concentration of dissolved substances in the sample.

Ristretto

A restricted shot of coffee, often with 2/3 or 3/4 the amount of water compared to an espresso.

Roast

The process of applying heat to raw, green coffee beans.

Roast Profile

A graph tracking temperature probe measurements during the roasting process.

Rosetta

A common latte art design, loosely resembling the rosetta flower.

Second Crack

A phase during the coffee roasting process, characteristic of darker roasts. Loud popping noises created from the release of Carbon Dioxide and oil from the beans.

Short Macchiato

A single shot of coffee with a small dollop of milk froth.

Shower Screen

A part of the group head assembly in an espresso machine. This disperses the water coming out of the group head, spreading it more evenly over ground coffee. Also known as a dispersion screen.

Slurry

The mixture of coffee grounds and water created during brewing.

Specialty Coffee

A term referring to a higher grade of coffee involving close scrutiny at every level of the supply chain including how the coffee was farmed, processed, traded, roasted, and brewed. Strictly speaking, this is coffee that scores at least 80 out of 100 points determined by licensed Q graders.

Steam Wand

The part of the espresso machine that dispenses steam to heat and froth milk.

Sweetness

There are naturally occurring sugars in coffee that are caramelised and browned during the roasting process.

Tamper

A tool used to compress ground coffee into the filter basket used in espresso brewing.

Tartaric Acid

Organic acid that can be found in coffee. Contributes to grape-like mouthfeel and flavour in coffee. A major contributor to tannins in coffee.

TDS

Short for Total Dissolved Solids, this refers to all the dissolved substances present in a solution. In a coffee context, the TDS in brewed coffee is measured to assess how much was extracted from the ground coffee, with most baristas aiming for an 18%-22% extraction. TDS is also measured in water to assess its hardness. A refractometer is the most common tool to measure TDS in coffee.

Time

Elapsed time from the moment water touches coffee til the end of the brew.

Tulip

A common latte art design, loosely resembling a tulip.

V60

A pourover dripper manufactured by Japanese company, Hario.

Varietal

Similar to grape varieties in wine, this refers to the different genetic types of coffee plants cultivated by farmers and horticulturalists. There are thousands of coffee varietals around the world. Common varietals include Ethiopian Heirloom, Typica, Bourbon, and Caturra. Gesha or Geisha is a particularly famous varietal known for its low yield, delicate floral and citrus flavour profile, and higher price.

Volumetrics

The measurement of volume. Most automatic espresso machines have programmable buttons using volumetrics to dispense specified amounts of water.

VST

Short for Voice Systems Technology, a company that manufactures precision filter baskets and refractometers for coffee.

Washed Process

This involves removing the fruit from coffee cherries with water and mechanical methods before drying the coffee seeds in the sun.

Water Hardness

The amount of dissolved minerals in water. Greatly influencing how coffee is brewed.

WDT

Short for Weiss Distribution Technique, this is a technique used in espresso brewing involving a tool equipped with fine needles to distribute ground coffee and remove any clumps before tamping and extraction.

Yield

The weight of brewed coffee.