The Arabs discovered in the late 13th century that applying heat to coffee beans, grinding the beans, and boiling the grounds in water, would release the unique aroma and taste of coffee. Many other methods of preparing coffee were practiced. The berries can be fermented to become a wine, the leaves and flowers can be dried and prepared as a tea, the raw beans can be soaked in water and spices and eaten like candy, or the husks of the dried coffee fruit can be boiled with spices to make qishr, a Yemeni drink.
Despite all this, roasting, grinding, and steeping the beans produces the drink that captivated the world. When the coffee bean is roasted, oils are produced that give coffee its beloved primary tastes. In addition, sugars in the bean caramelize, contributing to color, body, sweetness, complexity, and flavor.
The Arabs roasted beans over an open fire, and the Europeans roasted the beans in their ovens. In the 19th century large roasting equipment developed, turning coffee roasting into a commercial operation.