The roasting process
Coffee releases over 800 compounds during roasting - almost a third of them representing important aromatic notes. There are two important phases in the roasting process: the first crack and the second crack.
During the first phase, the coffee beans rapidly absorb heat and water within the bean turns into steam. As the steam creates more and more pressure within the bean, you can hear audible ‘pops’ - this is known as the first crack.
During the second phase of the roasting process, the decomposition of sugars, proteins and lipids takes place. The pressure driving the second crack is not caused by build-up of steam, but by the
formation of gases like C0, C02 and N0x being driven out of the bean.
The freshly roasted coffee beans are then ground, soaked in hot water and left to stand while the flavours develop. Then Chris and a small group of experienced tasters note the particular smell and taste characteristics of the brew. This is make or break for a sample batch of beans. A thumbs up at this stage means that an order will go out for a bigger shipment of the same green beans, from the same farm. When the shipment arrives, the original roasting profile is fine-tuned so it can be transferred to the large roaster.
According to Chris there are no rights or wrongs when it comes to how you like your coffee. But there is definitely an art to coffee roasting — that’s something best left to the experts.