Things to know about coffee...
The coffee, which is nowadays drunk in Europe, comes mainly from the beans of the coffee plants Coffea arabica and Coffea robusta. These plants, which are sometimes referred to as trees and sometimes as bushes, belong to the plant family of the rubiaceae, which also comprises the bedstraw and the woodruff.
The Coffea is a rather delicate plant, which on the one hand needs sun and warmth, but on the other hand requires high humidity and should not be exposed to direct sun. Big changes in temperatures or temperatures below 10° C are not good for the plant. For these reasons the main coffee-growing regions are located between the 22nd and the 26th latitude south of the equator. The most important coffee-growing regions in South America are Brazil, Costa Rica, Ecuador, El Salvador, Guatemala, Honduras, Jamaica, Columbia and Mexico; in Africa Ethiopia, Kenya, Rwanda and Tanzania; on the Arabian Peninsula Yemen; in Asia Java, Papua New Guinea, Sumatra and Vietnam; and in Oceania Hawaii.
The coffee bush has small white flowers whose smell is similar to that of jasmine. After the blossoming period the plant develops berry-like fruits which need about 6 months to ripen. During the ripening period the colour of these berries changes from green to yellow and finally to red. Therefore the ripe fruits are also called coffee cherries. Under the red skin of the coffee cherry there is the pulp which houses two seeds – the green coffee beans. A thin parchment and the silverskin wrap around the beans. The ripe coffee cherries are picked by hand or shaken down from the trees.
The processing: The coffee cherries are washed and then filled into a pulper where the pulp is removed from the bean. Afterwards the fermentation process starts, which usually lasts between 12 and 36 hours. During the fermentation process the remaining pulp peels away from the beans. In a fermentation tank the beans are finally washed free from the remaining pulp. The beans are then left to dry for about one to two weeks. Then the parchment and the silverskin are removed by milling. Rotten or unripe beans are eliminated and the good beans are sorted by size using special machines. Roasting usually takes place in the coffee consumer countries. The coffee beans are roasted in a kind of tumble drier (at 230° to 270° C) or in a hot air tube (at 200° to 280° C). During the roasting process the colour of the beans changes from green to a light or dark brown. After the roasting process has been completed, the coffee is quickly cooled down in order to make sure that the aromatic and essential oils are not lost. 12 hours after roasting has been completed the coffee is ready for use.
The exact composition of the substances contained in the ripe berries depends on the type of coffee, the growing region, the preparation and the age of the coffee. Generally it can be said that Arabica beans contain about 0.9 – 1.4 % of caffeine, while the caffeine content of the Robusta beans is about double as high.
Coffea arabica originally comes from Ethiopia, where the stimulating effect of the beans is said to have been discovered as early as in 850 AD. The first wild-growing Coffea robusta plants were discovered in Uganda as late as in 1860. Coffea Arabica was first cultivated in Yemen in around 1500, where farmers grew the bushes in terraced gardens and where coffee was roasted on hot stone plates. From the Arabian Peninsula the consumption of coffee soon spread to the entire Ottoman Empire. During the Second Turkish Siege coffee was first brought to the city gates of Vienna. From this time people in Vienna started to take a liking to drinking coffee, so that during the following centuries Vienna became a city of cafés with a very characteristic coffeehouse culture.
In the human body caffeine stimulates the central nervous system and triggers the following reactions: The phase of activity in the nerve cells becomes considerably longer, an effect which makes people feel more awake and which increases their concentration and attention for about one and a half to five hours. Furthermore caffeine accelerates metabolism and digestion, helps burn calories and dilates the blood vessels.
Substances contained in coffee
| Carbohydrates | 30 – 40% |
| Fats | 10 – 13% |
| Water | 10 – 13% |
| Proteins | 11% |
| Acids | 4 – 5% |
| Mineral nutrients | 4% |
| Alkaloids | 0,8 – 2,5% |
| Natural flavours | 0,1% |
