How can you best grow coffee?
There are 124 different coffee plants around the world, with only the two varieties Arabica and Robusta playing a role in the global coffee trade, with a market share of around 96 percent. While lay people often associate high quality and full taste with Arabica coffee, the Robusta has fallen into disrepute as an inferior coffee. A hasty generalization, however, does not do justice to the Robusta in particular. After all, coffee lovers can also experience great taste experiences with this variety.
Climatic conditions and countries of origin
Coffee plants need a balanced climate in order to thrive perfectly. Too much sunshine and temperatures of over 30 and below 10 degrees Celsius make the plant suffer and have a negative effect on the harvest. Average annual temperatures of 18 to 25 degrees Celsius are ideal. Coffee finds optimal conditions in the coffee belt of the tropics around the equator between 23 degrees north and 25 degrees south latitude. The largest coffee producers in the world are Brazil, Vietnam and Indonesia, followed by Colombia, Ethiopia and Peru. The names “ highland coffee”, “coffee arabica ” and “ robusta ””Are not sufficient as a quality designation, rather the growing conditions (soil, climate), the time of harvest, the type of processing of the coffee cherries and the roasting of the beans are decisive for a high quality product.
Differences in varieties
The Robusta Coffee plant is, as the name suggests, a bit more robust than the Arabica coffee plant. It can withstand somewhat higher temperatures and the Bean has a higher caffeine content. However, the coffee plant is also sensitive to temperatures above 30 degrees Celsius, especially when the humidity is low. The Arabica bean, which is often considered to be of high quality, grows at high altitudes between 600 and 2100 meters. The Robusta bean, on the other hand, prefers lower altitudes from 0 to 800 meters above sea level. Robusta also thrives in regions with more rain and grows in very high humidity, while Arabica suffers badly from warm, humid air and this has a clearly negative effect on crop yields.
Growing conditions and harvest
The optimal soils for high-yield coffee cultivation are deep, loose, well ventilated and permeable to water. Nitrogen, potassium and phosphoric acid ensure an ideal supply of nutrients to the plants. In addition, a soil rich in humus and a neutral to slightly acidic pH value are advantageous for growing coffee. For example, soils with volcanic ash are ideal for growing coffee. The harvest takes place in different periods of the year depending on the growing area and the ripeness of the coffee cherries. Since the coffee cherries ripen individually on the bushes, each fruit has a different degree of ripeness. A particularly high-quality green coffee is created when coffee farmers harvest the fruit by hand using the so-called picking method.
In contrast to the harvester’s stripping method, which strips off all the cherries from a branch and thus also harvests unripe coffee cherries, the coffee farmer only picks the individual fruits when they are ideally ripened. For reasons of cost, such harvesters are often used on large plantations such as Brazil or Vietnam, which is why the quality there is often not as high as that of coffee beans from smaller plantations. With the stripping method, the selection process of the coffee cherries is more important than with the picking method. In addition, the reject rate is significantly higher with the stripping method, since a comparatively large number of unripe fruits are harvested.
The picking method, on the other hand, is much more time-consuming and is used less and less against the background of increasing intensity in industrial coffee production. After the harvest, the coffee cherries are dried and processed, then the pulp, the mucous layer and the parchment skin are removed from each bean and, if necessary, further drying is carried out. The dried beans are filled into sacks and usually shipped unroasted.
Climate change and coffee growing
The effects of climate change hit coffee producers particularly hard. The plants are very sensitive and have very specific requirements in terms of temperature, humidity, soil conditions and rainfall. Higher temperatures primarily affect the Arabica, while the temperature fluctuations associated with climate change affect the Robusta in particular. Experts anticipate that, particularly in Brazil, many areas under cultivation will be lost in the next few decades and cannot be absorbed by new developments in the country.
Instead, the focus is on new cultivation areas in East Africa and Southeast Asia, where coffee cultivation has so far not been worthwhile. However, it is questionable how the new areas can be developed sustainably. While development in East Africa appears to be quite unproblematic, many cultivated areas in Southeast Asia are covered by rainforest. Extensive clearing would have fatal consequences for ecosystems and would further accelerate climate change. On the other hand, there is a growing global demand for coffee that producers have to serve.
Conclusion: growing coffee
Coffee plants are sensitive and place comparatively high demands on their environmental conditions for optimal growth. So that coffee connoisseurs can ultimately hold a perfect bean in their hands, not only the climatic conditions but also the soil conditions, the time of harvest, processing and roasting are decisive.
- Coffee plants only thrive near the equator, as they need temperatures of at least 13 degrees and a maximum of 30 degrees
- The soils must be deep, loose, well ventilated and permeable to water
- Nitrogen, potassium and phosphoric acid supply the plants with nutrients
- Climate change and increasing global coffee demand are the most important challenges for future coffee growing