Thursday, June 16, 2022

Natural or dry method processing of coffee

When coffee reaches the consumers in its roasted form, it has gone through several phases. First as a coffee cherry which is harvested and processed, then as a green coffee bean prepared for roasting. There are four main methods used to process coffee: Washed Process, Natural (or Dry) Process, Wet hulled and Honey Process.

Dry process is a method of processing coffee beans to remove the fruit of the cherry and dry the bean. In the dry method, the usual objective is to harvest all cherries simultaneously with the least percentage of unripe ones.

The ideal situation is to harvest all fresh, ripe cherries with the least possible damage to the tree, irrespective of the processing system to be used. The cherries are picked ripe, which is important since the fruit itself imparts flavour during this process. They are sorted and weighed before moving to the drying area.

In this method, the coffee cherries are laid out in the sun on a concrete drying patio. The coffee on the drying patios is shifted every 30-40 minutes. Throughout the course of 3-6 weeks, the coffees will ferment, as producers rake these cherries and rotate them to prevent spoiling. During this time, the sugars and mucilage (that sticky substance that coats the seed) will latch onto the seeds, which develop flavours and make them sweeter.

Coffee must be dried from approximately 60% moisture content to 11-12% moisture content. After a period of 3 - 6 weeks, the husk of the dried cherry is removed mechanically. The resulting coffee is often referred to as unwashed. This is the oldest method of processing coffee and is more ecologically friendly, as it does not require water.

This method is widely used in Brazil, but less widely used in Guatemala or Costa Rica where the coffee is more often piled perpendicularly to the old piles.
Natural or dry method processing of coffee

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