Search This Blog


Friday, 8 October 2010

The coffee transformation in the roasting process

The starting point is green coffee. It contains around 12% moisture and has a mild herbal fragrance. The craft of the roaster is to bring forward the best aromatic compounds through the roasting process, Each coffee needs its own rhythm and we respect that. We are not in a hurry...

Coffee after being in the drum for the first 5 min at a temperature of 200 C, in this phase the coffee beans absorb the heat ( endothermic ), water evaporates and due the pressure the cells start to expand. The blueish hues of the coffee are turning into pale yellow.

10 minutes in the drum, 225 C temperature.Coffee is expanding and loosing weight, carbohydrates are turning into sugars.During this phase the beans puff up, doubling in size due to internal pressure exerted by carbon dioxide. At that stage we reach a critical moment the Maillard reaction, where more than 700 new compounds are created, including key volatile aroma compounds responsible for the characteristic coffee flavor. At this point it has a baked bread aroma.
15 min in the drum, we reach the cinnamon roast, caramel notes are arising the temperature is at 240 C .At this stage each minute counts and will affect directly the final taste.
20 minutes in the drum, is time to go for cooling. This is a medium to dark roast. The smell of coffee is all around, the creation is made.

1 comment:

regina mir said...

es increible como el cafe cambia a traves del calor o la torrefaccion,sus componentes varian,o se transforman a cada minuto que pasa en su tratamiento,olores,azucares....
creo que es todo un arte!
es muy intesante.
todo un mundo!