A couple of years ago, when I was starting into the coffee world, my husband brought me some coffee from Mexico from an area that I was not so familiar with with respect to their coffee. This area is the state of Guerrero along the Pacific Coast of Mexico. The coffee was so unique, so delicious, like nothing I have tasted before. It reminded me of drinking Kalhua. We found out that this coffee was grown and roasted by a small group of farmers in Atoyac de Alvarez and what made this coffee different is that it was processed dry or natural.
The next time I heard about the natural process was when I approached the Mexican Coffee Association to find out more about these coffees to see if I can import them into Europe. They told me that the “Kalhua” taste was not so much the coffee itself, but probably due to a fermentation of the coffee. Which is true and very interesting. But unfortunately at that time natural process was almost synonym of low quality coffee and therefore hard to obtain.
Later, as I learned more and more about coffee, I tried some amazing coffees when in Ecuador: both natural and wet processed. The differences in flavour are remarkable and since the beginning of my coffee roastery I have worked with both processes. So let me elaborate on what is exactly a natural or dry process coffee and what makes it special.
Coffee, though called a bean, is not really a bean: it is a seed. Two seeds – two coffee beans- are nestled inside a coffee cherry, so basically the coffee we roast is seeds of fruits. There are multiple ways to process the fruits in order to remove the seeds: natural (dry), washed (wet), pulped natural and honey.
The natural process is the oldest method. After picking the cherries from the coffee trees, first of all the un-ripe (green) and defective cherries should be removed by hand from the batches. Then the remaining fruits are placed in patios, or even better on tables, to dry under the sun. Hence, the entire fruit will dry. The once soft juice cherry has to remain drying for 14 to 25 days until it turns hard to the touch, it shrinks and becomes dark brown/black. The inner fruit by then has the consistency of a raisin. The drying is considered to be done when the moisture content is 12.5% or less. A higher percentage leads to rot. A resting period usually follows during which the dried cherries are stored until sold. This time, 2 or 3 months will allow the taste to mature. Finally, a hulling machine removes the dry skin from the seed.
One big advantage of this process is that no water is required, so it is sustainable in the long term. This method is used where local conditions restrict access to water. Some producers do put the cherries through a quick wash to easily separate the debris from the fruit instead of picking them by hand.
However, extended periods of sunshine are necessary. Nowadays with climate changing sometimes farmers have to run to protect their drying cherries from sudden rains (unexpected outside rainy season), or gusts of wind in which the now dry cherries can easily blow away. And due to high humidity in some places the cherries are not dried outside but in “green houses” under controlled environment. Some companies even use drying machines to speed up the process. The best practice, however, remains to be the slow dry that assures that the coffee keeps its attractive qualities for longer times.
Which attractive qualities would that be? Well, this dry process accentuates the sugar profiles in the coffees. It adds fruit flavours in all coffees regardless of variety and origin. The coffee develops hints of berries, raisins or even tropical fruits. In coffees from Brazil or Ecuador it adds some hints of nuts. Another advantage of the natural process is that the farmer can play with the variables: sun exposure, moisture level, shade, and so in order to develop the flavours that he finds interesting.
Worldwide there is an increasing demand for natural and other semi-washed process. The “bad name” of natural as a cheap process for low quality coffee is changing due to the attention on quality control during the process starting from the moment of picking the cherries. It is important to pick only the ripe cherries. As the fruit ripens sugars develop and create interesting flavours. Then the drying itself: selecting the best place with direct sun to dry, placing the cherries in thin layers and turning them regularly to ensure even drying and preventing moulding, fermentation or rotting taking place. A common practice is to place the cherries on the ground, though raised beds are highly recommended. Not only as a clean surface to put the cherries on but also because the wind circulation assures the cherries to dry evenly. Finally, during the drying period it is necessary to control the moisture to decide when the coffee is ready. For some producers below 12.5% is an accepted rule, some others have found better taste when drying down to 10%. Moisture is even more important once the dried fruits are collected and stored to avoid over-fermentation which would add an unpleasant flavour.
Washed beans (left) and natural beans (right) both from Cariamanga, Ecuador -green
Due to the additional labour involved the natural process is not necessary a cheap process. But in my experience natural coffees have a wilder nature, boozy, robust, deeper character perfectly reflected in your cup of coffee. They are more challenging to roast, but the reward is definitely worth the effort. Something that is typical of natural coffees is that the beans are very unevenly coloured: from light green to yellowish or even cinnamon colour depending on the influence of the juice of the berry. This gives also a rather uneven coloured coffee after roasting that consumers have to get used to. Traditionally unevenly coloured coffee is considered the result of fast and bad roasting. However, for natural coffee it’s almost impossible to get an even roast due the variation in colour of the green beans. Therefore, the next time you see in your coffee store what looks like a unevenly roasted coffee first check what kind of coffee it is. If it’s a natural, give it a try and you may be pleasantly surprised!