Coffee cherry is divided into water washing type and dry type, flat bean and round bean. Coffee beans are dark and light in color. Through deep baking, coffee beans explode, double their volume and reduce their weight by nearly 1 / 4. Coffee beans gradually produce volatile flavor oil during baking, so as to achieve a perfect balance of various flavors. Even in the same producing country, coffee beans will subtly affect the flavor and quality of coffee beans and produce their own characteristics because of the differences of climate, altitude and soil quality in different regions. The earliest way Arabs ate coffee was to chew the whole coffee cherry to absorb its juice. Later, they mixed ground coffee beans with animal fat as a physical supplement for long-distance travel. It was not until about 1000 A.D. that green coffee beans were boiled in boiling water to become an aromatic beverage. Three centuries later, Arabs began baking and grinding coffee beans.