Extraction (in coffee) is the removal of soluble material from ground coffee into the cup. Soluble material simply refers to anything that can be dissolved by water. These include all of coffee's aromatic compounds, as well as melanoidins, which are responsible for coffee’s colour.
Having a ‘good’ or ‘even’ extraction simply means you have taken out all the desirable compounds, and have left the bitter polyphenols behind.
Baristas can increase or decrease extraction through a number of different variables, including grind size, temperature and coffee dose.
These variables apply to you at home, too! Check out our previous blog posts on the basic variables here.
Come back next week to see what F stands for!
Photography by Michael Clement: https://www.michaelclement.co.uk/