Sourcing of SLVR'Coffee™
To find out more about the silverskin and the roasting process, we have visited the coffee roastery mirò, a small coffee roastery in the heart of Zurich, Switzerland.
Coffee is prepared from roasted coffee beans, the seeds of the fruits of the coffee plant (Coffea arabica).
The fruits of the coffee plant are red, cherry-like drupes (coffee cherries) and they consist of several layers. Surrounded by pulp, the core contains two seeds, which are called “coffee beans”. The innermost layer of the coffee cherry enveloping the coffee beans is the coffee silverskin, which is botanically known as the epidermis. It is a very thin, silver-shining shell that protects the coffee beans.
The process of coffee production involves several steps. After harvesting the coffee cherries, the wrapping layers are separated from the coffee bean in either a dry or a wet process to obtain the green coffee bean, which is still covered by the silverskin.
The next step involves the roasting of the green coffee beans. Prior to being roasted, the coffee beans contain approximately 11 % of internal moisture. The heat of the roasting process converts this moisture into steam, which causes the bean to expand. Consequently, the silverskin splits from the coffee bean and falls off. The silverskin is the main by-product that is generated during the roasting process, and large amounts of coffee silverskin accumulate in coffee roasteries around the world.
Alfonso, the chief roaster in mirò, has shared some insights with us. He takes care of the coffee roasting and provides the coffee with freshly roasted beans once a week.
Watch here the video, where he explains the roasting process and which part the silverskin plays in it!