Blending and roasting


Blending
In order to achieve a good espresso, the blending stage is surely of fundamental importance. For a proper blending of coffee, several aspects of the raw material must be taken into account: if we are handling Arabica or Robusta, washed or natural coffees, South American, African or Asian beans, their percentage and obviously the quality of green coffee.

Roasting
Our magical �green gold� is heated inside the roasting machine at a temperature ranging from 200 to 230�C. This must be done in a very consistent way, in order to guarantee a homogenous product.

During the roasting process, the beans lose their weight by 18 to 20%, depending on the coffee origin, and increase their volume by even 60%. There is then the formation of the aromas in the coffee, which are several hundreds. The texture of the bean changes from hard to rather crumbly and oils start to appear on their surface. The colour of the beans can change according to the temperature achieved: the more they are roasted (risking to burn the coffee), the darker they will be and the more bitter they will taste.
The more rapidly the beans are cooled off, the better the aromas will be preserved. The whole process can vary in duration, depending on the kind of roasting chosen. On average, it should last about 15 minutes, although an expert roaster can decide to choose the �right moment� to end the cycle, even by the �music� produced by the beans.

http://www.planetcoffee.it/greek/blending-and-roasting/the-coffee/blending-and-roasting.html