Roasting coffee at first seems deceptively easy. Pop some raw, green beans into an oven and in a little while, take them out all brown and roasted. In fact, roasting coffee is a developing science and far more complex than it first appears.

The aim of a Master Roaster is to produce coffee that has been roasted to an ideal flavour point. This is a point at which the flavour has developed sufficiently to create a complex balance of body and intensity with a bittersweet chocolaty character. It’s a tricky undertaking and requires that the roaster taste the coffee constantly. Too light a roast and the coffee will taste grassy and hemp-like. Too dark and it begins to lose its natural sweetness as the sugars are caramelized. If it is roasted even darker still, it actually turns the natural wood-fibre in the beans (cellulose) into charcoal. This results in a charred, ashy and very unpleasant espresso.

In order to achieve their aim, and after much testing and tasting, a roaster will set in place a roast profile which is essentially a graph of temperature in relation to time. A typical profile may have the roaster choosing to start the roast cycle with less heat and increasing the heat towards the end of the cycle, this process is called ramping. It sounds simple enough however there are a couple of critical factors to consider in order to produce the desired result. Firstly, there is a relationship between the air temperature in the oven and the increasing temperature of the beans. The roaster, therefore, needs to decide at what point to start ramping as well as how long to maintain the ramping. Secondly, every coffee will vary in density and moisture content which will affect how the green coffee develops in the roaster.

All in all there are many factors to be considered in producing a high quality roast and many advances in technology and tools available to the Master Roaster in order to help them achieve this. However in the end it is the passion of the Master Roaster, their experimental spirit, their scientific knowledge and their undying commitment to learning all that they can about their craft that results in a truly exceptional roast time and time again.