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Coffee Arabica and Robusta

INFORMATION

Coffee production on the island of Sumatra is thought to have begun around 1884, near Lake Toba, which is the largest volcanic lake in the world.
Within the years, the coffee was spread through Sumatra Island, one of them is in West-Sumatra. The coffee growth in Solok, the highland area in Sumatra, which is the best place for coffee to growth and produce high quality products.

Coffee from Sumatra is known for being low acid coffee. There are several reasons that this is the case, but the way the local farmers process the coffee is the most important one. The process is known as wet hulling or ‘giling basah’ in the local language.

Coffee from Sumatra is mostly from the arabica species. This means that the caffeine level is pretty standard. Arabica coffee has less caffeine than robusta, but on the other hand it tastes better.


The Process Behind Coffee Arabica and Robusta

1. Harvest


Robusta coffee takes 8-11 months from bud to ripe, while Arabica coffee takes 6 to 8 months.

2. Sorting and Pealing


After the coffee cherries are harvested, immediately do the sorting. Separate the fruit from dirt, diseased fruit and fruit defects. Also separate the red fruit from the yellow or green fruit. Smooth and red fruit separation (superior fruit) with inferior fruit is useful for distinguishing the quality of the coffee beans produced.

Peel the skin of the coffee cherries, recommended with the help of a peeler. There are two types of peeling machines, manually turned and machine powered. During stripping, run water continuously into the peeler.

The function of flowing water is to soften the fruit skin tissue so that it is easily separated from the seeds. The result of the process of peeling the fruit skin is seeds that still have horn skins, or also called HS coffee beans.

3. Fermentation Process


Ferment the peeled seeds. There are two ways, first by soaking the seeds in clean water. Second, pile the wet seeds in a cement tub or wooden tub, then cover the top with a burlap sack that must always be moistened.

The duration of the fermentation process in a tropical environment ranges from 12-36 hours. The fermentation process can also be observed from the layer of mucus that covers the seeds. When the coating is gone, the fermentation process can be said to be complete.

After fermenting wash the seeds again with water. Clean the remnants of mucus and fruit skin that is still attached to the seeds.

4. Drying Process


The next step is the fermented HS coffee beans are dried. The drying process can be in the sun or with a dryer. For drying, spread the HS coffee beans on the drying floor evenly. The thickness of the seed pile should be no more than 4 cm. Turn the seeds regularly, especially when they are still wet.

The drying time is about 2-3 weeks and will produce coffee beans with water content ranging from 16-17%. While the desired water content in this process is 12%. The water content is the equilibrium water content so that the coffee beans produced are stable, not easy to change taste and resistant to fungal attacks.

To get the water content as desired, do further drying. However, this step is usually a bit long considering that previously the coffee beans have been soaked and fermented in water.

Usually, further drying is carried out with the help of a tumble dryer until the moisture content reaches 12%. This step will save more time and effort.

5. Pealing Process


After the HS coffee beans reach a moisture content of 12%, peel the skin of the horn that covers the beans. Peeling can be pounded or with the help of a huller. Recommended with a machine to reduce the risk of damage to coffee beans. The results of stripping at this stage are called green beans.

6. Final Sorting


After the coffee beans are produced, do the final sorting. The goal is to separate dirt and broken seeds. Furthermore, the coffee beans are packaged and stored before being distributed.


Product and Specifications