In the coffee process, first the fruit flesh (pulp and parchmentlike hull) is removed, and then the kernel is dried, resulting in green coffee beans.
A typical coffee bean has the shape of a half ellipsoid with well rounded edges. It contains about 12% of water and most of this is lost in the early stage of roasting, followed by a loss of up to 8% of the dry bean material.
The green coffee bean has a very tight structure where less than 7% of its pore volume has a diameter of 10 nm or more.
The two coffee beans are covered by a thin parchmentlike hull, which is further surrounded by pulp.
Physical properties of coffee beans
