Acidity

Acidity is a natural component in coffee, often seen described as “sharp”, “juicy”, or “bright”. Although many people consider acid to be an unpleasant characteristic of food or drink, acidity in coffee (when correctly extracted) adds both balance and flavour complexity.    

Arabica

Originating in Ethiopia, arabica (from the Coffea arabica plant) is the most common species of coffee produced and makes up the majority of the market. Arabica beans are now grown and produced in tropical climates all over the world, including from within South America, Africa, and Asia. Today, approximately 60% of the world's arabica beans are produced in Brazil.   

Automatic coffee machine

Automatic coffee machines offer a full brewing experience at the touch of a button. These machines have a programmed menu or several buttons to allow for the user to easily select their beverage of choice. Most automatic machines these days are fully customisable, allowing the user to adjust the amount of coffee, water, and milk in each cup.  

Batch brew

A filter style coffee brewed in a batch (i.e. in a large quantity). Although batch brewers and filter coffee have been around for decades, these brewers have become more popular in recent years and are now a menu staple at most specialty coffee houses. 

Blend

A mix of two or three different coffee beans (generally of a lower grade and from different origins) creates a blend. Blends are most commonly used in milk-based espresso drinks (e.g. latte, cappuccino, flat white). 

Bloom

The initial period of extraction where a small amount of hot water comes into contact with ground coffee to fully saturate and degas the grounds. 

Body

Often referred to as “light”, “medium” or “dark” and refers to the heaviness and consistency of coffee on the palate e.g. thin, heavy, syrupy, creamy. Can also be described as the “mouthfeel”. 

Brew ratio

The brew ratio refers to the amount of ground coffee to water used in a brewing recipe. For example, a 1:2 ratio is generally used in a standard espresso recipe - this means 1 part ground coffee to 2 parts water. 

Brew time

The time it takes to extract your brew e.g. the brew time for a single shot of espresso is 18 - 25 seconds. Timing your brew period ensures that you're getting consistency in your coffee.

Cascara

The dried husk or “skin” of the coffee cherry, cascara is brewed as a tea. Often with tasting notes of citrus or dried fruit.

Crema

The thick layer on top of the espresso made of natural oils which is formed by high water pressure being forced through ground coffee. The crema on your coffee can also be an indication of the freshness of your coffee beans, and how well your espresso has been extracted. The crema is typically light brown, golden, or dark tan in colour.  

Degassing

The natural process of carbon dioxide being released from recently roasted beans (formed during the roasting process). Due to this build up of Co2 in the beans, it's recommended to leave freshly roasted coffee beans for about a week before use, so that the gasses can be released and the full flavour potential can be achieved.  

Dose

The dose is the amount of coffee used in your brewing recipe. 

Dual boiler

A coffee machine that has two separate boilers – one for steam and one for brewing (espresso). Dual boiler coffee machines are often top-of-the-line machines, offering more power and precision than what would be produced from a single boiler coffee machine. 

Espresso

Characterised as a short and strong coffee brewed under high pressure and for a short period of time, and with a notable thick, foamy layer on top (the crema).   

Extraction

This is the process of dissolving the solubles in ground coffee by using hot water and (generally) high pressure. Ideal extraction should leave you with a well-balanced coffee that has a pleasant taste and mouthfeel. When coffee is over-extracted, it tends to be bitter or even 'burnt' in taste. On the other side of extraction, under-extracted coffee will leave you with a sour and sometimes vegetal-tasting coffee. 

Filter roast

Generally a lighter roasted single origin coffee suitable for filter style coffee (pour over, Chemex, batch brew).

Green beans

Green beans are the unroasted (and unpalatable) coffee beans bought by roasteries or those who enjoy roasting their own coffee beans at home. 

Group head

The group head is the part of the coffee machine that you lock the portafilter into. This is where hot water is poured through the ground coffee and espresso extraction takes place. 

Heat exchange

A single boiler coffee machine with a heat exchanger 'tube' that runs through the boiler, which allows the user to run espresso and steam milk at the same time without lag. Heat exchanger machines are popular home espresso machines due to their precision, convenience, and price point. 

Immersion 

Referring to immersion brewing, this is a brew method that consists of immersing ground coffee (generally of a coarser grind) in water and is typically brewed for a longer period of time (anywhere from several minutes to several hours). Types of brewing that use the immersion method include cold brew, French press, and Aeropress.  

PID

In simple terms, a PID (or proportional-integral-derivative controller) applies a responsive correction to a function (in this case, the machine’s temperature). The PID monitors and restores the temperature accurately and with minimal delay, allowing the user to consistently use the coffee machine without incurring any lag.  

Portafilter (also known as a group handle)

Refers to both the handle and the metal basket that sits inside of it, a portafilter is used to hold the dose of ground coffee before locking it into place in the group head. 

Puck

The residual coffee leftover in the basket after extraction which is then discarded. The puck can also indicate if an espresso has been correctly extracted - a used puck should be relatively firm to the touch and should hold its shape easily once knocked out of the basket. An overly wet or overly hard puck is normally an indication that something in the brewing process needs to be adjusted (e.g. the dose, the grind, or the brew time). 

Ristretto

A ristretto refers to the act of intentionally cutting a shot of espresso short i.e. leaving out the first or last section to intensify certain flavours. Typically brewed at a 1:1 ratio. 

Robusta

The second largest coffee species, contributing to 30 - 40% of coffee production. Robusta beans (from Coffea canephora) are typically bitter in taste and have a higher caffeine content than Arabica beans, so are generally used in a blend for espresso to add strength and body, and to create a richer crema. 

Single boiler

A coffee machine with only one boiler, generally recommended for black coffee drinkers. Although single boiler machines typically allow the user to make both espresso and steam milk, this can't be done simultaneously (unlike in a heat exchanger or dual boiler machine). 

Single origin

Single origin coffee beans come from one specific origin – this can be one country or region, one farm, or one lot. As these beans tend to be a higher grade, they are not blended with any other beans and are typically more expensive than blends. 

Shot

Generally refers to a single 30ml espresso.

Specialty coffee

Specialty coffee refers to premium, high grade coffee, generally single origins. For coffee to be considered specialty, it must score over 80 points on a 100 point scale.