Coffee Roasting - Stages & Factors

Roasting Terms

 
Green beans: coffee doesn't start in those beautiful browns, but as green coffee "beans" which are actually the seeds of a fruit called a coffee cherry

The Roasting Process:

Drying: the beans release steam, as they increase in temperature, and change from green to brown
First Development: the coffee beans begin to give off their familiar scent, become less "grassy", turn light brown, begin to smoke
First Crack: the coffee beans begin to make loud cracking noises, not unlike popcorn, as the beans begin to split open
Second Development: the beans begin to darken, caramelize, and expand
Second Crack: quieter than first crack, coffee begin to change very quickly after this stage, beans become very dark, and can more burnt tasting
Resting: after the coffee beans are finished roasting, it is normal to allow them a rest period to de-gas for 1-3 days before using them
Degasing: gases build up during the roasting process, and release from the beans. Quickly within the first 24 hours, then more slowly as the coffee ages
Chaff: light pieces of skin/hull that detaches from the outside of the coffee beans in the roasting process
 

Roast Types

The type of roast, in terms of light/medium/dark is not determined by the type/origin of the coffee beans, but by the roasting process/time length
Light roasts: are lighter brown in colour, dull with no sign of oils on the beans, have higher acidity, have a subtle taste like that of toasted grains, have a prevalent flavour origin (you can taste more of the natural flavours present from the country of origin)
Medium roasts: have a darker brown exterior, less dull exterior, less prevalence of flavour origin, more full body taste
Dark roasts: dark brown in colour, slight to moderately oily surface, the flavor can be overtaken by the extended roasting process, the coffee will have a more intense taste, can taste slightly burnt when roasted towards the French/Italian side of the spectrum
Although dark roasts may have the strongest and boldest flavours, light or medium roasts may have more caffeine.
Coffee Roasters us a more advance scale of coffee roasting that goes beyond Light, Medium and Dark:
Consumer Coffee Roast Levels:
- Light
- Medium
- Dark
Coffee Roaster Roast Levels:
- Cinnamon
- American
- City
- Full City
- Vienna
- French
- Italian
*Roast types for our coffee
 

Roasting & Origin of Coffee Impact Taste

During Roasting he coffee not only undergoes physical changes, such as expansion and colour change but also chemical changes, such as the breakdown of caffeine.
That being said, along with roasting length, the country - even the coffee farm the coffee comes from - also has an impact on the flavour of the coffee; as well as the rainfall, nutrients in the soil, sunlight vs shade, vegetation present & more!
Three senses have to be in play when roasting: sight, smell and sound. One needs to observe the changes in colour as the beans progress from light to dark roasts, listen to the timing of loud "cracking" stages of the beans as they dry, expand and release gases, and inhale the wonderful aromas that fill the room.
Our coffee is roasted fresh every week at Elpida Cafe & Roastery, 14 The Queensway, S, Keswick!