About coffee

Origin legend, discovery and etymology

According to legend, the coffee plant, which originated in Africa, was discovered by an Islamic prophet named Mohammed. In his stories, the dark hot drink was offered to him by an angel and subsequently he felt the stimulating effect of the product for the first time.

Another legend says that an Ethiopian shepherd from the Kingdom of Kaffa observed a herd of goats. This was more active at night than other herds. This higher activity always occurred after the goats ate from the bushes of the plant. The shepherds reported to the monks in the nearby monastery and complained about it. When the shepherd then ate the fruit of the shrub himself, he experienced the same stimulating effect. While searching, the monks discovered plants with fruit that resembled a cherry. They poured hot water on them and felt their invigorating effect, so that they stayed awake for nights.

Thus, from today's perspective, it seems obvious that coffee originated in the Kaffa region and has done so since the ninth century. Five years later, with the help of slave traders, coffee was shipped from Ethiopia to Yemen on the Arabian Peninsula and spread further. Through coffee cultivation, Arabia became a monopoly and the port city of Mocha (now Muhka) in Yemen became a central hub of trade. In Ethiopia, many peoples either did not prepare coffee at all or prepared it quite differently. The typical method of preparation was developed only later, at the end of the 19th century. Thus, the tradition of coffee production and preparation dates back to that time. Until then, the Christian Amhars had labeled coffee as well as tobacco as stimulants of the Muslims. Consequently, they rejected it because it did not seem compatible with the Christian religion.

The preparation of coffee at that time began with the beans being roasted in a large pan and then coarsely pounded with a mortar. The product was then boiled with hot water and served with sugar.

The term "coffee" can also be translated as wine with the Arabic word "qahwa". The Turkish word for coffee is "kahve". The Italian word "caffe from "cahue" has also entered the French vocabulary. In German usage, it is translated as coffee. Thus, the spellings differ only slightly in some cases. In Germany, the English term "coffee" initially prevailed and was not replaced by the term "Kaffee" until the 18th century.

There is an exciting anecdote about coffee in connection with a famous poet. Johann Wolfgang von Goethe had the idea of distilling the beans of coffee. This was put into practice by the chemist Friedlieb Ferdinand. In the process, he discovered caffeine.

Pleasure
Initially, only well-socialized citizens and aristocrats could afford the invigorating drink coffee. The poorer classes of the population were given drinks that resembled coffee. These were, for example, the drinks muckefuck, malt coffee, chicory or stragelkaffee. In many countries, it became a ritual to drink coffee in the afternoon. However, the coffee drink was also consumed directly with meals or after the meal. In socially disadvantaged classes, the consumption of coffee was considered something special for a long time.

Curiosities
In the next section, there are some curiosities that probably only very few people know in connection with coffee. The oldest coffee house in Germany is called "Zum arabischen Coffe Baum". This was opened in Leipzig in 1711 and is still in operation after more than 300 years. A coffee museum is located on the upper floor. The coffee house thus looks back on a long history.

Nevertheless, coffee consumption was not always viewed positively. Rather, the now popular hot beverage was also criticized early on. Likewise, prominent personalities gave their opinion on coffee to the best.

Johann Sebastian Bach responded humorously to criticism in his Coffee Cantata. There is a canon entitled "C-a-f-f-e-e, don't drink so much coffee!". The King of Sweden Gustav III tried to portray the coffee plant as poisonous. He wanted to prove this by giving one pardoned prisoner coffee every day, while another prisoner was given tea every day. Then he observed the reactions together with a team of doctors. According to legend, however, the two prisoners survived both the doctors and the king.

Cultivation: Climate
Coffee bushes must not be grown in temperature extremes. Too much heat (temperatures above 30°C) and cold (temperatures below 13°C) are harmful to the coffee plant. The ideal temperature for growing coffee should be between 18 and 25°C. 250 to 300 millimeters of water per month are needed. Therefore, there must be at least 1500 to 2000 millimeters of water in the form of precipitation during the year. Wind and sunlight have a negative effect on the coffee plant, so hedges and shade trees protect the plants from direct sunlight. Ideally, the soil should be well aerated, loose and permeable. Coffee plants are grown between the tropics at a preferred altitude of 600 to 1200 meters above sea level. These conditions meet the requirements of coffee plants. Climate change will significantly shrink the area under coffee cultivation. Rising average temperatures, precipitation and extreme weather events are making coffee cultivation much more difficult. In addition, there are fungal diseases around the world that also harm cultivation.

Cultivation: propagation and care
Coffee is propagated by seeds (coffee beans), cuttings or propagules. The highest germination capacity is reached in seeds about eight weeks after fruit ripening. After that, the germination capacity of the plants continues to decrease. After five to six weeks, the first two leaves of the seedling form. These are then transplanted into containers and cultivation takes place in nursery beds. Eight months later, the seedlings are planted in the plantation, each one to four meters apart. There, the plants are pruned to 1.5 to 3 meters. After three to five years, the coffee plant has reached its optimum yield. This yield then remains for the next ten to twenty years. After that, the yield drops significantly.

Cultivation: Harvest
The coffee is harvested once or twice a year. South of the equator, harvesting begins in July and ends in December. North of the equator, harvesting takes place from April to August. In the immediate vicinity of the equator, year-round harvesting is possible. Generally, harvesting takes between ten and twelve weeks, as the fruits ripen for different lengths of time. For this reason, selective harvesting by hand ensures a much better quality of the fruit, as only the ripe fruits are harvested. Especially Arabica coffee is picked by hand, this is also called "picking method". Another method is the "stripping method", where all fruits are picked either by machine or by hand. Subsequently, the fruits of the coffee plants are sorted to improve the quality. Strip harvesting is used for Robusta coffee. This method is also used for Arabica coffee in Ethiopia and Brazil. Harvesters are only used on larger plantations in Brazil. Worldwide, the average green coffee yield is about 680 kg/ha. Nevertheless, yields can vary significantly. For example, this is 1620 kg/ha in Costa Rica, 33 kg/ha in Angola and 4200 kg/ha in Brazil. To be able to harvest 60 kg of coffee in its raw form, 100 Arabica trees are required for the harvest.

Cultivation: Preparation
In order to extract green coffee, the pulp, the parchment membrane and the mucilage formed around it, as well as the silverskin, must be removed. This is done using either a wet or dry method. Meanwhile, there are farmers who use special types of preparation. This can help change the flavor profile of the coffee. Natural, dry-processed coffee is usually fuller-bodied and sweeter in flavor than wet-processed coffee. The latter tends to be more complex and clean tasting. When the two types of preparation are blended together, the result is a clear coffee that has a slight sweetness.

In the following section there is more information about the methods of wet and dry preparation:

Wet processing:
Wet processing starts within 12 hours if possible, but no later than 24 hours after harvest. First, the fruits are cleaned with water and pre-sorted. Then the fruit skin and pulp are crushed. The parchment skin and associated mucilage continue to adhere to the beans. With the help of sieves and an alluvial channel, the coffee beans are transported and stored in fermentation tanks. There, fermentation occurs so that the mucilage changes its aggregate state. This liquefies so that it can be washed off. After the coffee has been fermented for 12 to 36 hours, the coffee beans are washed and dried to a water content of 12%. Consequently, 130 to 150 liters of water are needed to harvest one kilogram of market-ready coffee. Wet processing takes place mainly in Asia.

Dry processing:
Dry processing takes about three to five weeks. In the preparation method, the coffee fruits, also called "coffee cherries", are spread out and dried. They are then reduced from a water content of about 50 to 60 % to a water content of 12 %. During this process, they are regularly turned over and the dry skin and dried pulp are peeled off with machines. Dry processing is mainly used in Africa, Brazil and partly in other countries.

Semi-dry preparation:
In order to save water and still be able to ensure a certain quality standard, there is the option of semi-dry processing. The pulp is then removed and dried directly after washing instead of fermenting it. The dry pulp and fruit skin are then removed from the coffee beans.

Clean:
Freshly shelled coffee beans contain a sticky parchment skin (also called "parchment coffee"), which is removed together with the silver skin. Finally, any remaining impurities are removed from the beans. The beans are sorted according to quality and size. In the case of coffee considered to be of high quality, they are even sorted by hand. The product then yields the green coffee, which is now ready for the market.

Roasting:
After preparation, most of the green coffee is roasted. A small part is kept and used as "green coffee". Roasting refers to the process of strongly heating the coffee beans, usually under atmospheric pressure. During this process, various physical and chemical processes take place. These ensure that the release of aromas starts and the typical flavors of coffee are formed. Roasting is also known as the "Maillard reaction". This begins at about 60°C and ends at a temperature of 200 to 250°C of the beans. During this process, the ambient temperature increases significantly. In order to save time during the setup, some industrial processes even heat the ambient temperature to as high as 550°C.
The degree of roasting depends on the variety, the quality of the coffee beans and the roasting time or temperature. Thus, the aroma substances are released. These then affect the taste and digestibility. Fast roasts in industrial processes produce harmful substances, such as acrylamide or melanoidins. Dark roasts give a slightly sweet but bitter taste, and light roasts give an acidic but not bitter taste. The sour taste in coffee is explained by the existing chlorogenic acid. However, this is gradually reduced by the roasting process. Dark roasts therefore contain significantly less chlorogenic acid. The bean temperature rises up to 200°C until the so-called "first crack" is reached. This means that the gases produced in the beans, such as carbon dioxide, lead to a direct expansion of the bean. As a result, the beans increase in size after roasting (similar to the process of making popcorn). The First Crack process, unlike the "Second Crack," can be clearly heard acoustically. During the "Second Crack" (approximately at 225°C), superficial parts of the bean burst off. However, the roasting process is usually stopped before the second crack, since the desired degree of roasting has already been reached. Drying results in a loss of coffee substance, also called roast loss. The finished coffee ends up being about 18% lighter than the coffee in its raw form. Heat reaches the bean surface through convection, contact and radiation. Convection roasting is now mainly used. There, the coffee is enveloped with heated air. This leads to an improvement in heat transfer.

Roasting process:
- Continuous roasting
- Batch roasting in drum roaster or fluidized bed roaster

Degree of roasting:
Light: pale or roast with cinnamon aroma
Medium: American style roast
Strong: French style roasting
Double: roasting continental style
Italian: Espresso
In addition to the color, the amount of roasting loss also determines the degree of roasting.