Green Coffee Facts
What is green coffee?
The cleaned and dried seed of the coffee cherry which is ready for roasting called green coffee. Green coffee smells similar to barley, it’s very hard, and its taste is nothing like roasted coffee, it is
What is Arabica and robusta coffee?
There are two major coffee plant: Arabica (Coffea Arabica) and Robusta (Coffea Canephora). Arabica coffee is more aromatic, has lower caffeine, grows at higher altitude and more sensitive plant. Robusta is much less aromatic, has higher caffeine content and much easier to cultivate than Arabica.
Is there many variety of the Arabica coffee?
Yes, many varieties exist of the original Ethiopian variety called Typica. These are the results of natural mutations and cross breading. Some of the best known varieties: Typica, Bourbon, Caturra, Maragogype, Geisha, Pacamara etc. Some of these has a specific taste characters others are taking their characters from their growing region and the way the green coffee is processed.
How is green coffee prepared?
First the coffee cherry has to be harvested. The cherries are on one tree do not ripe at the same time, so picking just ripe cherry (key to good coffee) has to be done by hand, many times during the
After harvesting the pulp of the cherries must be removed. It is often done by hand, when a pulping machine is used it’s called wet milling.
The moisture content of the beans at this stage is around 60%, should be dried to around 10-12% to avoid mould building up and rotting. It is usually done by spreading the beans onto drying patios or
raised beds, sometimes with drying machines.
After pulping the coffee beans are still in their protective cover – the parchment- which has to be removed a dry miller. This process is called hulling.
After hulling the green coffee beans are graded and packed in jute bags of 60 or 69kg ready to be shipped to roasters.
What are the typical coffee processing types and what effect does it have on taste?
The way coffee beans are processed has a dramatic effect on the taste. The typical processes are:
Also known as dry process is the oldest way of preparing the green coffees. The coffee cherries are laid out dried on sunny patios right after harvesting. When the pulp is dried it is removed mechanically from the seeds.
This process often adds fruity, sometime spectacularly fruity flavours to the coffee.
During this process the pulp and the mucilage are removed as fast as possible. After pulping the seeds are still covered in sticky mucilage which is removed in a water tank where carefully monitored fermentation takes place. The fermentation breaks down the mucilage than it can be washed away. This process usually gives higher acidity, increased complexity to the coffee, describes as clean cup.
– Honey process:
In this case, after pulping the coffees are dried with the mucilage on. The mucilage has high sugar content, and this effects the taste. This process usually gives a bit lighter acidity and lot of sweetness to the coffee.
– Wet hulled process:
After hand-pulping the mucilage is not washed off, the coffee is dried with the mucilage still present on the beans. Coffee (still in their parchment) is dried only half way (40-42% moisture content) when it is sent to hulling (removing the parchment). This is called wet hulling which gives the coffee beans their famous deep bluish green appearance. The result of this processing is that the coffee’s taste is intense, sweeter, features heavy body and low acidity characteristics.
Historically, “Monsooning” of coffee first happened quite by accident in the days of sailing ships, when it took about six months for unwashed (cherry coffee) coffees to reach the Europe. During this period of long voyage the coffee on account of being in the damp hold of ships exposed to humid sea winds, lost its original colour and acquired a special aged coffee flavour which was liked by the consumers in Europe. However, with the opening of Suez channel and speedy transport by steam ships, the transportation time over the seas has drastically reduced to about one month and the coffees reached their European destination without prolonged exposure to high humidity winds over the sea.
As a result, the unwashed cherry coffees reached Europe without the characteristic musty monsooned flavour. This led to a compliant from the European consumers who missed the distinctive musty flavour. To cater to this demand for musty flavour coffees, the coffee exporters situated in the Malabar Coast devised and perfected the process known as “Monsooning of Coffee” in which they successfully recreated the unique aged coffee flavour.
When the coffee is processed, graded and filled in jute bags the coffee bags are placed in special warehouses. When the humid monsoon weather arrives the outer walls of the warehouse are removed letting the humid air to weather the coffee beans, recreating the conditions of long sea voyages. This changing the coffee’s physical and chemical properties. The result of the monsooning is a very low (nearly zero) acidity, heavy body, somewhat mellow cup.