Overview of Coffee

Sep 27, 2024

3 min read

From plant to cup

For one of the most consumed drinks in the world, coffee is little understood by many people, but that’s what we’re here to fix! So lets get started!

Firstly, Where its grown!

Coffee is grown all across the world, these places span across what is called “the coffee belt” which is a section of the globe that fits right between the tropic of Cancer and the tropic of Capricorn.

Due to different soils and different strains of the coffee plant, each country or area will have different flavour profiles for the coffee beans grown there. Don’t even get me started on different species of coffee plant and differing altitudes! These are topics for another post as this is a overly simplified summary for today.

Secondly, its from a fruit!

Coffee cherrys image by Daniel Reche

Yep, this is coffee! All beans start their lives as the seed within a coffee cherry. These are then picked when ripened to a deep reddish colour and ready to go into processing.

There are two main ways to process the cherries, these are wet process and dry process. There are more ways but lets not complicate things just yet. The main thing to know is that the fruit flesh is removed and the bean inside is then checked for defects like insect damage and weird sizing.

Green coffee beans image by Michael Burrows

Green coffee being sorted and checked for defects image by Michael Burrows

Once fully processed and sorted into different graded classifications of beans, they are then sent off to wherever they’ve been bought. Coffee is always roasted in the country that its to be consumed in as sitting roasted coffee on a boat for a week in transit wont make for nice drinks, this is due to a degassing process in which beans, once roasted, start to give off their CO2 and also expel their flavour compounds.

Anyway, once the green coffee (unroasted beans are a pale green colour) reaches its destination at the roastery, the roasters will get it all stored away and get to testing. A lot of roasters will travel out to the farms and roast the beans as a sample before purchasing, but once the full delivery arrives they will need to go through extensive cupping sessions to determine the best roast for these beans based off their own tastes.

Cupping in glass image by Michael Burrows

Cupping is done by coffee professionals to get the flavour of a bean completely independent to different brewing methods. They’ll try many different roast profiles usually using a sample roaster and then when cupping them all together in individual bowls they can taste test them all and pick a favourite, through this trail and error they can determine their set roast profile and start full scale roasting.

Roasting!!!

Roasting is done in one of these:

Roaster and cooling drum image by Maksim Goncharenok

Roasting takes place within the rolling drum section of the roaster which is above a heating element or flame, this moving drum helps to prevent the beans from scorching against the very hot metal of the drum.

With a little scoop the roaster can monitor the colour of the beans and once ready to the trained eye of the roaster or using a colorimeter they will open the door and let the beans flow into the round cooling tray as seen above, this then cools the beans very quickly as they will continue to brown whilst cooling so to match the colour needed for their roast profile they must come down to room temperature asap!

Once cooled, the beans are sealed in bags and sent to either cafes or people buying for home use, from there the beans will be ground for whatever brew method needed and turned into the cup of coffee you enjoy on a daily basis! (There’s a few extra steps to instant coffee production and this will be covered in a future post.)