We tend to categorise our roasts into 5 different roast names: Light, Light Medium, Medium, Medium Dark and Dark. We mainly roast our coffees around the middle of the scale as these roasts tend to give a good balance of the positive charactaristics of the lighter and darker roasts.
All of the roast levels require the coffee to go through the early roast stages of Drying, Colour development and then First Crack. First crack is reached when the pressure in the bean builds up until they pop or "crack", casting off the silverskin (papery husk). This is where the roasts start to differ, the stage after First Crack is known as the Roast Development. A Light roast coffee will be removed from the roaster soon after the start of First Crack and so the roast isn't allowed to develop for long. This results in high acidity and less sweetness as the sugars in the coffee are not allowed to caramelise.
As the roast develops, the sugars start to caramelise creating more sweetness to counteract the acidity in the cup. As the coffee reaches a Medium roast there should be a good balance of sweetness and acidity, as well as an increase in body. As the roast develops further, the body increases at the expense of a decrease in acidity. The roast reaches a Medium Dark and the beans are starting to pick up roasted flavours as some of the sugars start to caramelise further, creating the start of an increase of bitterness. The coffee will eventually reach second crack, when the oils in the beans start to burst out. As the coffee reaches second crack it is now a dark roast, if the roast is continued the coffee will increase in bitterness and lose all sweetness and acidity, until all the flavour compounds are destroyed entirely and all that is left is acrid, tarry bitterness.
All of the flavour compounds which make each Single Origin coffee different from others are best appreciated anywhere from a Light roast to a Medium Dark roast. This is because they are accentuated by the sweetness created by the caramelisation of the coffee sugars, or perhaps they are amplified by the acidity in a light roast. We decide on the roast profile by first roasting a sample of the coffee as a Light roast. We then taste the coffee to see what flavours we taste in the coffee. We then decide if we think these flavour profiles would be best accompanied by acidity, or sweetness, or a balance of both, or maybe some malty nuttiness from a medium dark roast. We then roast the coffee how we decide and taste test it to check we've got it right!
We do not roast our specialty grade Single Origins any darker than Medium Dark, as once you start to reach a Dark roast, all of those individual unique compounds which are the result of the terroir of the particular farm the beans came from, start to get burnt and just taste burnt. If you wish to drink a Dark roast coffee, then you are better off drinking a cheaper blend as burnt coffee beans from one of the most exclusive coffee producers in the world, taste like burnt beans from anywhere.