Mayan-like pattern typically found on traditional garments.

COFFEE PROCESSING

Coffee bean artwork used as a paragraph separator.

Natural vs. Washed

Natural vs. Washed

Mayan-like pattern typically found on traditional garments.

Natural? Washed? You've probably noticed these terms on your coffee packaging but, what exactly do they mean? They refer to the process used in the farm to prepare coffee beans for export and consumption. Let's explore both of them and learn how they impact your morning brew.

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COFFEE ANATOMY

To clearly understand these processes we must first have a clear picture of the anatomy of the coffee fruit, commonly known as the coffee cherry. Every layer of it will play an important role and will be handled differently.

The coffee cherry is more or less the size of a grape. It has five main layers wrapping the seeds:

Drawing of the anatomy of a coffee cherry.
Drawing of the anatomy of a coffee cherry.

1. Exocarp: The cherry’s outer skin. It starts off green and, as the fruit matures, develops intense colors of red, yellow, or orange, depending on the genetic variety.

2. Mesocarp: Also referred to as mucilage, or pulp, this is the fruity layer of the cherry responsible for its sweetness.

3. Pectin Layer: Made out of cellulose (sugars), this slimy coating will be key in the fermentation stage.

4. Parchment: A papery substance protecting the seeds. It will become crumbly as it dries.

5. Silverskin: The innermost layer of the cherry wrapped directly on the seed. This last line of defense is very thin, but also very tough, and will only be removed once the beans are roasted.

6. Seed: Technically called the endosperm, but better known as the coffee bean. 95% of the time there are two beans in each fruit. They face each other, making them flat on the front but round on the back, and represent most of the volume of the fruit. Only around 5% of the harvest will have one seed inside instead of two. These are known as peaberries and are completely round in shape. They are believed to be of better quality so are handled separately.

Scroll through the following pictures to get a closer look of the fruit:

Green, unripe coffee cherries on a tree.

1. Unripe cherries

Mature coffee cherries on a tree.

2. Mature cherries

Harvested coffee cherries held by a person.

3. harvested cherries

Extracted seeds from the coffee cherry on someone's hand.

4. extrated seeds

Green, unripe coffee cherries on a tree.

1. unripe cherries

Mature coffee cherries on a tree.

2. mature cherries

Harvested coffee cherries held by a person.

3. harvested cherries

Extracted seeds from the coffee cherry on someone's hand.

4. extracted seeds

Now that we have a good idea of the fruit's anatomy, we can discuss how it is processed. There are several different methods but, in this article, we will be focusing on the two most popular ones. Keep in mind that they are complete opposites of each other, but the goal remains the same:

1. To remove all the layers

2. To dry the beans to an appropriate level.

The difference between both lies in the order in which this is done.

NATURAL PROCESS

Also known as the dry process, this is the oldest and more traditional of both techniques. The aim is to keep the cherry intact, during harvesting and through the entire drying stage, allowing the bean to absorb the sweetness of the skin and mucilage. This technique requires very little infrastructure and practically no water.

These are the steps:

1. Initial Sorting:

After picking, the cherries are meticulously hand sorted by size, density, ripeness, and color.

2. Drying:

The cherries are spread out in a thin layer, on brick patios or raised beds, to dry under the sun. The latter option offers better airflow, which improves evenness. The cherries are turned regularly to avoid fermentation, mold, or rotting. They are covered at night and during rainy days.

3. Final Sorting:

The now dry cherries are sorted by hand to remove any noticeable imperfections.

4. Hulling:

They are sent to a mill to remove the now hardened outer shell consisting of the skin and pulp. Because part of the mucilage and pectin layer have dried over the beans, they are left with a brownish color.

Scroll through the following pictures to see each step in action:

Two men sorting picked coffee cherries on a farm.

1. Initial sorting

A man grabbing coffee cherries drying on raised beds.

2. Drying

Several women sorting dry coffee cherries.

3. final Sorting

A hulling machine removing the dry skin from the coffee beans and sorting them by size.

4. HUlling

Two men sorting picked coffee cherries on a farm.

1. initial sorting

A man grabbing coffee cherries drying on raised beds.

2. Drying

Several women sorting dry coffee cherries.

3. Final sorting

A hulling machine removing the dry skin from the coffee beans and sorting them by size.

4. HULLING

Flavor Profile:

The natural process leads to a higher sugar content infused into the seed. This adds fruity/floral flavor notes, as well as more body, to the final cup. For instance, our Yirgacheffe Natural offers incredible notes of berries and lavender.

However, through this method, the genetic makeup of the seed is not the main focus. Instead, we are highlighting the impact of the fruit on the bean.  

Additional Notes:

The natural process originates from places without reliable access to water, making it the only option. Moreover, it requires little infrastructure compared to its washed counterpart. The downside is the higher risk for mold and over fermentation, which is why natural coffees are usually considered of low quality.

Nevertheless, techniques have drastically improved. So much so that properly processed natural coffees are in high demand and at a premium because of how unique they can taste. More farmers are incorporating them into their portfolios.

Furthermore, it is a much more Eco-friendly technique.

WASHED PROCESS

Also known as the wet process, the objective is to remove and wash off all the layers around the seed before drying it. Obviously, this requires great quantities of water, but it allows for quality consistency because they are removing variables to worry about later on.

Let us dive into each step of the process:

1. Initial Sorting:

The cherries are sorted to remove unripe coffee. They pour the cherries into a large tank and fill it with water. The ripe fruits sink to the bottom and are pumped into the main processing area. Unripe fruits float to the top and are removed to be handled separately.

2. Skin & Pulp removal:

The cherries are passed through a pulper to remove the outer skin and flesh. The machine presses down the cherries, squeezing the seeds out. At this point the seeds still have some mucilage and pectin on them.

3. Fermentation:

The seeds are moved to a clean tank where the remaining mucilage and pectin will ferment. As microorganisms act on the fruit, these layers start to breakdown, making it much easier to wash off. Many factors influence how long fermentation will last but, the warmer the climate is, the faster it will occur.

This must be closely monitored since over fermentation will result in unpleasant flavors. A common way of checking its completion is by placing a stick upright inside the tank. If the stick doesn't fall over it means the water is gelatinous enough to hold it, proving that fermentation is done.

4. Washing:

The coffee is washed in separate tanks to remove the broken-down mucilage.

5. Drying:

This can be done by spreading the seeds on a patio or placing them on raised beds. They must be turned regularly with a rake in order to achieve an even dry. This can last between 10 and 20 days since the beans’ moisture content must go from 60% to around 10-12%.

It is becoming more common for farms to use mechanical dryers to avoid bad weather and add a layer of control. However, this requires a big investment that may not be justified for certain producers.

6. Hulling & Final Sorting:

The beans are passed through a huller machine that will detach the dry and crumbly parchment. Afterwards, they are graded by density and size.

Scroll through the following pictures to see each step in action:

Ripe coffee cherries exiting a sorting water tank.

1. initial sorting

A pulping machine removing the exterior layers of the coffee cherry.

2. skin & pulp removal

Coffee beans fermenting in a tank to remove the mucilage and pectin layer.

3. Fermentation

Coffee seeds being washed to remove the fermente mucilage.

4. Washing

Coffee seeds drying on a patio under the sun.

3. drying

A hulling machine sorting the dry coffee beans.

4. HULLING & Sorting

Ripe coffee cherries exiting a sorting water tank.

1. Initial sorting

A pulping machine removing the exterior layers of the coffee cherry.

2. Skin & pulp removal

Coffee beans fermenting in a tank to remove the mucilage and pectin layer.

3. fermentation

Coffee seeds being washed to remove the fermente mucilage.

4. Washing

Coffee seeds drying on a patio under the sun.

4. drying

A hulling machine sorting the dry coffee beans.

4. HUlling & sorting

Flavor Profile:

Wet-processed coffees produce higher acidity, generally displaying notes of lemon or apple. They usually deliver a cleaner cup, meaning it will specifically showcase the genetics of the bean as it thrived in that particular environment.

Additional Notes:

The washed process requires a reliable source of water and significant infrastructure. It is normal to see this kind of facilities in larger farms that have the necessary funding. Unfortunately, smaller farms cannot afford the investment, which is why coffee cooperatives are becoming more common. A cooperative is a group of producers who join forces in order to gain access to more resources. Together they can afford to build the necessary processing infrastructure and also leverage better business opportunities.

The main drawback about the washed process is that the waste water can be toxic. Therefore, farmers are encouraged to have a system in place to clean it before reintroducing it to the ecosystem.

BAGGING

The beans are now ready to be packed in either 60 kg. or 69 kg. jute bags, depending on the country. Jute has traditionally been used because of its low cost and little environmental impact. However, in order to protect the beans from moisture, some farms line the bags with a protective material, such as a polyethylene film. New advances are constantly being researched to better protect the beans during export.

OTHER PROCESSES

The washed and natural processes are by far the most commonly used. They are also at extreme opposites of the spectrum. Every other method is somewhere in between these two. They all consist of removing the skin and mucilage before drying. But, variations lie in how much is removed.

Some of the more popular ones are:

1. Honey & Pulped Natural:

Right after de-pulping, the seeds are put to dry without undergoing fermentation. Since they still have a significant amount of mucilage on them they'll exhibit a lot of body and fruity notes, although not as strong as the natural process.

The differences between Honey and Pulped Natural are very blurry since they are extremely similar and every farm has their own definition. But, generally speaking, the honey process has a little more mucilage than the pulped natural. Often times the terms are used as synonyms of each other.. and that's ok.

Regardless of the exact definition, as the coffee dries, the mucilage oxidizes and darkens. It starts off yellow but slowly turns red and finally black. Each color correlates to a particular flavor profile. So, farmers can decide to package and ship the coffee once it reaches the desired tone.

2. Semi-Washed:

The beans are allowed to ferment after de-pulping, but only for a limited time. Thus, the mucilage doesn't break down as much as in the washed process allowing a certain amount to remain on the beans. Again, this will add some body and fruity notes but also some of the acidity and cleanness of the washed process.

CONCLUSION

Understanding the different methods used to process coffee beans puts into perspective the amount of work involved. So, make sure to always analyze the label's information and meditate on the implications it has on your morning brews.

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We hope this article was informative. If you have any questions, shoot us an e-mail at info@ixkanulcoffee.com. We’ll be more than happy to assist you.

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