It’s all in the roast
 In its natural state, a coffee bean has plenty of caffeine, protein, acids, water and sugar but very little flavour, and therefore needs to be roasted. During the roasting process, its interior reaches about 400ºF, upon which it produces the aromatic oils that give coffee its unique flavour and aroma. Roasting is a precise skill; insufficient roasting fails to fully extract the oils, but excess roasting can see them burnt away entirely.
 
Each coffee has its own characteristics, for example, Santos coffee has a soft smoothness, Kenya coffee has a lively acidity and Costa Rica coffee has a delicate sharpness. Each coffee has its own character and is at its best at different stages of roasting. All coffee seeds, however, must have the outer pulp removed in order to be ready for roasting which develops the aroma and flavour of their essential oils.

Some coffees are medium roasted, others dark or very dark roasted. Generally, the longer the roasting the darker and stronger the coffee. 

Medium roast
A medium roast produces mild or medium to strong coffee depending on the variety. Medium roast is a favourite with breakfast, but it can be enjoyed throughout the day. Medium roast coffee can be served black, with milk or with cream, and can be prepared using all types of coffee maker. Some coffees with a delicate flavour like Jamaica Blue Mountain are at their best when medium roasted.

Medium to dark roast 
A medium to dark roast is as the name indicates, a midpoint between medium and dark roasting. The process is mainly the same as with the medium roast but with a heavier, slightly stronger flavour.

Dark roast 
Dark roast is a much richer coffee, suitable for breakfast time and throughout the day, and especially after dinner when a more full-bodied depth of flavour is required to harmonise with richer food. Dark roast can be prepared using all coffee makers and served with milk at breakfast time, black or with cream any time of day.