Ripining of hazelnuts varies according to local climate, height
above sea level, variety of the hazelnut (harvesting time of Cakildak
variety is approximately 20 days later in comparison with
Tombul variety in the same climate and geographical condition).
Harvesting is done from the middle of August to the end of September.
Husk of hazelnut has a green colour during growing and
evolving phases, it is yellowish green prior to harvesting and
brown after harvesting and drying as shown in Fig. 1. After husk
separation made by compact harvesters or separator-machine,
the shelled hazelnuts are dried up to 4–6% humidity under sunshine.
The cracking process is made by shelling machine which
uses centrifugal principles. While the shells of hazelnut are mostly
used as primary fuel for different purposes, on the other side the
kernels are shipped for processing in chocolate factories (see
Fig. 2).