The coffee roasting process creates flavour and aroma. During roasting, the heat causes a series of chemical reactions. Starches are converted into sugars, some acids are created, and others are broken down. The basic cellular structure of the bean eventually melts, causing the bean to "pop", like popcorn. Proteins are broken down into peptides, and these emerge through the surface of the bean in the form of oils. Moisture and carbon dioxide are burned off and, for a darker roast, pure carbon will be created. Every coffee has its own characteristics and the best roast is the one that maximizes all the "origin character" of the coffee.

The machine we use is a drum roaster from Petroncini, Italy. It can roast 3.5 – 8 kilo at a time. 8 kilos of green beans will give us just over 6 kilos of roasted coffee beans, and depending on the amount, will take 15 to 20 minutes to roast.

When roasting, the last 3 to 4 minutes are the most important. During this critical time the roaster must stand by the machine and take out a couple of beans every so often to check if they are ready. Then the beans are cooled down with air to stop the roasting process. The quicker the cooling period, the better.

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