Category Archives: Roasting coffee

Natural or dry processed coffee

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.

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Ripe coffee cherry (in Guatemala)
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Coffee seeds (coffee beans) and the skin of one cherry

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.

Coffee cherries in Guatemala
Huge patio in Guatemala for drying coffee cherries (directly on the floor)

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.

Dried cheeries
Dried cherries

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
Washed beans (left) and natural beans (right) both from Cariamanga, Ecuador -green
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Washed beans (left) and natural beans (right) both from Cariamanga, Ecuador -roasted

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!

What is exactly espresso roast?

I write this blog trying to answer questions that I usually get when selling my coffee. One of the most common questions is: Is this coffee roasted for espresso. Well, where should I start. I don’t believe there is such a thing as “roasted for espresso” or “espresso beans”. In my experience we should enjoy the wide variety of coffees that nature has given us, and roast each coffee to its optimum roast. After that, we brew it to its best independent whether this is an espresso, a mocca, filter, cold or turkish coffee.

There are, nevertheless, different degrees of roasting, which names are a little bit arbitrary. But before going into this I first need to explain something about the roasting process. Roasting coffee is basically nothing more than slowly heating up the beans, but when doing so different process take place. Obviously the beans change colour: starting from green they get yellow, light brown and then darker and darker brown. While it’s getting darker brown chemical processes take place. At a certain temperature the sugars in the coffee beans start caramelizing, which releases water and carbondioxide gas. This makes the bean rapidly expand and sounds like making popcorn. This moment is referred to as first crack. Caramelizing continues with increasing temperature until all sugars have transformed and at this point the bean itself start decomposing: the physical fracturing of the cellulose matrix of the coffee begins. This point is called second crack because the beans again make a crackling noise; not like popcorn as with first crack, but more like the sound of crunching paper. First crack is clear to hear and hard to miss. Second crack is less predictable than first crack and the moment when second crack occurs highly depend on the type of coffee.

But, returning the different degrees of roast:

Light cinnamon: Beans have a light tan, flavour is dry, unpleasantly sour, little or no body. Reminiscent of cereal.

Cinnamon: Slightly darker than light cinnamon, but the taste and texture is little different.

City Roast: Light to medium brown; at the end of first crack. The bean surface is smooth due to the expansion during roasting. At this point the coffee starts giving off carbon dioxide. This was once the predominant roast in the United States. Varietal variance distinct. To our opinion the lightest roast one would like to drink, because starting from here coffee starts to taste like coffee.

Full City Roast: Medium brown. Coffee is at the verge of second crack. The beans have a slight sheen of oil. Body, flavour, and aroma are quite balanced.

Vienna or Light French: Medium to dark brown with drops of oil on the surface, second crack is under way, greater sweetness, carbonized sugars lend a caramel flavour; body exceeds acidity.

French: Surface is dark brown and lightly coated with oil; burnt notes become noticeable, acidity low.

Italian or Full French: Almost black, with a lot of surface oil. Tasted clearly burnt; acidity and even body are almost undetectable.

Judging the roast only from colour is tricky since different coffees have different colours at the same roasting temperature or degree. Our Galapagos, for instance is a light-coloured coffee and even at light french roast, while our Cariamanga Caturra is dark brown starting from the first crack. There is no standard in roasting: depending on weather conditions the temperature where first crack occurs may range from 170 to up to 190 degrees. Second crack may follow first crack almost immediately or only at considerably higher temperatures. So the trick is in the combination of monitoring the colour and the temperature and listening to first and second crack to decide whether the point one wants to stop roasting has been reached.

We studied and tested our coffees and decided to roast them to Full City Roast. Does this mean that they are suitable for espresso? Sure! We love espresso and we enjoy our coffee the best like that. We realise that many espresso drinkers believe coffee for espresso should be French roast or Italian roast, but we believe that an important part of the flavour of the coffee gets lost when roasting coffee that much. We like to distinguish the flavour of each coffee and that can only be done if not all sugars have been completely carbonized yet.

Roasting coffee the best possible way depends on many factors and also is a personal preference as some people prefer their coffee more bitter and others more acid. Whether a coffee is suitable for espresso or performs better in filter coffee depends on the body and after taste of the coffee. This is something specific for a coffee and the degree of roasting has only very little influence on this. Therefore we don’t like the idea of having a special “espresso roast” as it’s not so much the roasting that makes a coffee suitable for espresso, but it’s the coffee itself.

Finally, if you are curious about the roasting progress, check our youtube video:

http://www.youtube.com/watch?v=1xb7Qq2VC8c