The unique flavour and aroma of coffee depends not only on the quality and origin of the beans, but also on the degree of roasting and cooling. The secret to a perfect roast is to find the appropriate balance between the temperature and time of roasting. Just a small modification of the process is enough to obtain coffee with a different taste and flavour.
Skillful roasting is an art frequently supported by years of experience and excellent intuition. The best cup tasters know that the process of roasting must be constantly controlled, and that each coffee species or batch requires separate roasting. Nowadays, the vast majority of beans is roasted dark. Only a small percentage of grains is burned bright. This results from the customers’ needs and tastes – low acidity and strong, intense flavour coffees are most popular.
The green, unroasted coffee beans are bright, creamy, or greenish. They are acidic in taste and contain much more caffeine than the roasted beans. The beans contain sugar, which caramelises while roasting and the grains take on a brownish shade.
Coffee is roasted in appliances called roasters. The very process of roasting takes from a few up to a few dozen minutes, depending on the desired taste and aroma. Too short or too long roasting can spoil the taste of coffee. The longer coffee is roasted, the more intense the bitter taste and smoky scent, which might not suit everyone. On the other hand, coffee roasted not long enough may be acidic in taste and less aromatic. Each grain of coffee contains about 800 aromatic oils and a special care is needed to release as many as possible.
After roasting the grains are cooled – either with circulating air or with water. Although circulation with air lasts longer and is more expensive, it is much better, because the freshly roasted grains do not absorb water. The circulating air method is chosen by experts: in this process the grains are kept in constant motion, which lets them loose the temperature slowly and retain most of the aromatic substances.
Roasted coffee cannot be stored as long as the green one, because the aromatic compounds, released while roasting, can go stale. Thus, one should quickly pack the roasted coffee into air-tight containers, which prevent the loss of flavour.