Mon, Feb. 5, 2018
washed, naturals & honeys
the ultimate guide to coffee processing
by Asser B. Christensen
Coffee processing plays a crucial role in the flavor of the final cup. A few decades ago the washed process was ubiquitous when it came to specialty coffee, but in recent years new methods have become increasingly popular. In this article, you'll learn everything you need to know about how coffee goes from cherry to green bean.
When laymen talk about coffee, they often like to talk about dark or light roasts, or which country the coffee was produced in.
And while it’s true that these are indeed contributing factors to the deliciousness of the bean, something very important often gets overlooked in coffee discussions. And that is the processing.
There are dozens of different coffee processing procedures, and they all add their own unique touch to the coffee’s final flavor.
15 years ago most specialty coffee on the market was washed, but in recent years both farmers, exporters and roasters have started to hone in on processing. And for a good reason. As more and more experiments are being done, it’s getting clear that the difference between a coffee that is merely good and one that is world class, is mostly down to processing.
In this post we’ll go down the rabbit hole of coffee processing and tell you everything worth knowing about this fascinating and often overlooked part of the coffee cherry. Buckle up, we’re about to get geeky!
Coffee bean 101
But before we get into processing, let’s just have a brief biology lesson. See, your coffee bean technically isn't a bean. In reality, it’s a seed, and this seed is developed inside the coffee cherry.
Arabica coffee grows on small trees or bushes in countries close to the Equator.
Once the cherries are ripe and red, they are picked. Usually this is done by hand, but a few of the most advanced farms in Brazil do this mechanically. The cherries then go through a processing system in order to separate the two seeds (what we call beans) inside the cherry.
Stages from cherry to bean
Broadly speaking, three processing methods can then be applied:
- Washing (aka wet processing)
- The Natural method (aka dry processing)
- The honey process
When they've finished with whatever processing method the grower chooses, the coffee is then milled to remove a thin hard layer that protects the seed – this is called the parchment.
Workers will then hand sort the green coffee beans to get them ready to be exported.
Once in the country where the beans are meant to be comsumed, they will be roasted and sent to coffee shops or land on the shelves of the supermarket.
Fact: There are usually two seeds or beans inside a coffee cherry. When there's only one it's called a peaberry
The 3 Main Processing Methods
When you go into the finer subtleties, there are countless of ways to process coffee, but generally speaking they fall into three main categories: Washed, natural and honey.
Each processing method results in different flavors, and this is important to note if you're looking for a particular flavor in your coffee.
In the following sections I'll go in-depth with the finer subtleties of each of them.
The natural process
Photo: Natural processed coffee means simply drying the seeds inside the cherry
The oldest method for processing coffee beans is the natural processing method. You may have heard it called 'dry processing' as well.
Workers harvest the coffee cherries that contain the coffee bean, and they dry the entire thing intact on raised mats, beds, or patios.
Once the coffee cherry has reached the right moisture content, the coffee will be hulled to remove the coffee cherry's skin and the pulp. The only remaining portion of the original coffee cherry will be the seed or the coffee bean.
Back in the days natural processed coffee was considered low grade coffee. Since this kind of processing doesn’t remove the bad cherries the same way that washed coffee does, it would have more defects unless sorted manually by workers.
There’s also a lot of things that can go wrong during the drying process, so the farmers need to pay constant attention to the cherries.
In recent years, natural processed coffees have had a resurgence in popularity among specialty coffee buyers, so now some of the world’s most exquisite beans are actually naturals.
During the drying process, the coffee beans absorb the fruit's flavors, and this allows for a more intense, sweet flavor. You might experience a strawberry or blueberry note, and it's usually strong enough that people new to the coffee world can pick up on it. It's common to get very strong, sweet flavors that taste a little like wine with this process, as well as less acidity and a greater body compared to washed coffees.
There’s often a hint of fermentation in the flavor profile of these coffees as well. In fact, regions with a long tradition for eating pickled and fermented food, will often favor naturals. In paces like Taiwan and Korea you’ll find a big percentage of natural processed coffees in the coffee shops.
Pros & Cons
Originally, natural coffee processing started in places like Ethiopia or Yemen because they didn't have reliable access to water on a constant basis. When you combine this with the hot temperatures, you'll see that the coffee cherries had very little room for mildew growth. This made the natural processing method perfect for these areas.
The washed process
Photo: Washed coffee is being dried in Northern Thailand, Chiang Rai Province
The washed process is the most common and also the most consistent coffee processing method. The process takes place at a dedicated washing faclity. At the bigger farms in Latin America there is typically a washing station on-site, while in Africa it is common for small holder farmers to bring their cherries to local washing stations owned by coops.
It starts by soaking freshly picked coffee cherries in water to sort out unripe cherries. The green cherries will float and be easy to sort out. The seeds then go through a de-pulper that will remove the outer skin and pulp. A layer of slime will be left on the seed though – this is called mucilage and can be compared to the sticky layer that coats the stone of a peach.
In order to get rid of this mucilage, the seed will have to ferment in water tanks for 8-50 hours. The time the seeds are allowed to soak depends on the equipment, climate, and the preference of the producer. After that beans will be floated and rinsed once again. The beans are then dried on concrete patios or raised bed. When the beans have reached the right moisture content of around 11 percent the last protective outer layer of the seed (called the parchment) is milled off.
Washed coffee is what most people will recognize as 'normal coffee'. Compared to the other main scools of processing, it tends to increase the acidity and clarity of the coffee bean.
With this method, you typically end up with a refined and balanced coffee flavor. The best washed coffees have complex notes, a medium body and a pronounced acidity, while still being sweet. They are great for being brewed in a typical coffee machine.
Hazelnut, chocolate and spices are often used to describe the flavor of washed coffee.
In the best washed coffees you will most likely experience notes of citric and stone fruits, as well as florals.
Pros & Cons
Originally, wet coffee processing began in places that saw a lot of moisture, mist, or rainfall like South and Central America. They needed a processing method that would save the coffee beans from mold, so they turned to wet processing. It became very popular for its consistency and convenience.
The honey process
Photo: Some beans still wet with mucilage. It looks like they are soaked in honey
In spite of the name honey processing has nothing to do with actual honey. The name originates from Costa Rica, where coffee farmers would compare the sticky and sweet mucilage stuck to the bean with honey – “miel” in Spanish.
Ironically, this coffee tends to be very sweet and fruity, so the name somehow makes sense.
In recent years this method has become extremely popular with coffee snobs in all parts of the world, because it tends to combine the best aspects of both the washed and natural process.
The process starts by harvesting the coffee cherry and removing its skin. However, once the coffee cherry's skin is removed, the coffee cherry is laid out to dry with the mucilage attached to the seeds or coffee beans. Different producers like to play with leaving different pulp levels attached to the fruit.
Because the coffee cherry is stripped of its skin, but the pulp remains intact while it dries, this process brings out the sweetness and body of the coffee flavor.
Depending on how much pulp remains, it influences how the end product will taste.
Some are closer to the naturals and have flavors similar to dried fruits, while others are more forward and acidic. Usually, they are very sweet and pleasant though.
Pros & Cons
The kind of honey processed coffee that you are likely to encounter in a hip coffee shop today emerged in Costa Rica around 15 years ago. But actually there have been similar approaches in other parts of the world long before that. Especially Brazilian 'pulped natural' coffee shares a lot of similarities.
Yellow, Red, and Black Honey
These colors refers to what the coffee will look like when it’s being dried. Depending on how much of the pulp is left on the bean, different colors will develop.
- Yellow Honey - Yellow honey coffees go through a semi-washing process that is designed to leave less mucilage around the coffee bean. This leads to a cleaner and sweeter tasting coffee more similar to the washed method. The drying process is usually faster than the red and black.
- Red and Black Honey - Red honey has only had a little bit of mucilage removed, while black honey (picture on the right) has all mucilage intact. The drying period for these coffees is usually 12 days. The darker honey does very well in an espresso blend.
The Difference between Pulped Naturals & Honeys
While natural and washed coffee are easy to understand, the definitions can become somewhat murky when we talk about the honey process. Especially because some coffee regions have used a different terminology to describe what is essentially the same.
The pulped naturals of Brazil could also be called ‘honeys’ or maybe more precisely ‘red honeys’, as the process is similar.
Sometimes you’ll also hear the term semi-washed, which can again be compared to yellow honey.
It seems that the specialty coffee industry has taken a liking to the term ‘honey’, so this will most likely prevail in the future – maybe except when it comes to the of Brazil.
Photo: Honey processed coffee tends to look a bit like the old school breakfast cereal 'Honey Monster Puffs'.
How farmers Decide What Process to Use
Coffee producers want to make the most profit they can out of their coffee bean crops while maintaining a good flavor profile. However, they're limited by what they can do and how they can process based on their environment because coffee is closely tied to its growing environment.
Many producers won't decide on a processing method until they see how much rain falls in their area. If their area gets a lot of rainfall, it would be harder for them to use the natural processing method because the coffee cherries will split due to the moisture. If it doesn't rain or if the area typically sees less rainfall, it would be easier for the producer to use the honey or natural process because they won't have to worry about mold problems.
Processing Methods by Region
Historically speaking, different regions have used one coffee processing method, and they haven't branched out to other methods. This is slowly changing because people are looking for more diverse coffee flavor profiles, and producers are experimenting to give the consumers what they want.
Central America, Rwanda, Burundi and Kenya have historically used the washed process for their coffee beans. However, Brazil has historically used the natural or honey process for their coffee beans.
Fact: Washing coffee is an efficient way to sort out unripe beans as they will float instead of sinking to the bottom
But today, as the demand for new flavors and combination increases, coffee farms in most parts of the world are starting to experiment with the honey and natural coffee processing methods. Today, it’s quite common to see some of the most advanced coffee farms in countries like Panama and Colombia offer extremely expensive high-end natural processed geishas.
Other coffee producers are taking it a step further and starting to experiment with new techniques, using no fermentation or oxygen during the processing period. Some farmers have also begun looking for catalysts that will speed up the coffee bean's fermentation process. Finally, other coffee producers are trying to lessen their environmental impact and reduce the water amount used in their processing methods.
Lesser known Processing methods
Even though the majority of the world's coffee is produced by the natural, washed, or honey methods, there are a few other methods that are worth talking about. Some of these methods are new and experimental, while others are old and somewhat dubious.
Sasa Sestic, a world-champion barista, is known to use the so-called ‘Washed Carbonic Maceration’ to process coffee. The process starts with the coffee cherries being harvested and washed. Once they're washed, they're sealed in a stainless steel container that gets carbon dioxide pumped in to remove all of the oxygen from the sealed container.
Once the oxygen is out, the coffee beans will sit in water that is carefully monitored for temperature. These stainless steel containers are then put into greenhouses where the temperature is kept around 24 degrees celsius. This process allows the beans to macerate in a carefully controlled environment to ensure that the finished product has a very distinct flavor. It also makes it easier to duplicate the same flavors over and over again.
Acetic and Lactic Processing
The innovative Colombian Farm, 'La Palma y El Tucan' has created two different signature processing methods called ‘acetic’ and ‘lactic’ processing.
Both are variations of the traditional Colombian wash process, but with some key differences. The pulped beans are fermenting in special anaerobic tanks, where the oxygen flow and pH level can be controlled. This promotes the growth of certain strains of bacteria that will create either lactic or acetic acid. After the fermentation the coffee is dried in two stages. First on drying beds and afterwards in a mechanical dryer.
Photo: Ripe beans ready to be picked and washed.
Kenyan Processing aka Double Fermentation
Kenyan coffees are famed worldwide due to their high acidity, clean flavors and unique notes of apple, blackberry and tomato. Part of this is down to the unique Kenyan coffee varietals SL28 and SL32, but another reason is the special almost all coffees are processed in this country.
The Kenyan method is often called the double fermentation. The beans are first soaked for 12 to 46 hours to remove any pulping residue. Then they are washed and rinsed off. But then they are put in a second fermentation tank, where the process repeats itself for 12-24 hours – this time with significantly less sugar. Again, a wash and soaking follows.
After that the beans are laid out to dry in two stages. A rapid one and a slower one. When the coffee has reached 11-12 percent moisture content is ready to be milled.
Wet Hulled or Giling Basah
Wet hulling, called ‘giling basah’ in the local language, is the main processing method on the islands of Sulawesi and Sumatra, which are the biggest coffee regions in Indonesia. On islands like Java and Bali, however, washed coffee is the standard.
You could be forgiven for thinking that wet hulling and the washed method have many similarities, but in fact their flavor profiles couldn’t be more different.
In the world of specialty coffee, this kind of processing is frowned upon. It’s a bit like taking a nice piece of Kobe-steak and then smothering it with ketchup.
According to the coffee company Sweet Maria’s, who has been doing a lot of work with Indonesian coffee this is how it goes down: Usually small, independent farmers carry out the first step themselves. It involves removing the skin of the cherry and then fermenting the beans by letting them soak in whatever kind of tub, tank, plastic bag or container they have around.
Once they've soaked, the beans get washed to remove the layer of mucilage. The next step is to sun dry the beans for two to three days until the moisture content is between 20 and 24 percent.
At this point the farmers will sell the beans to a middleman, who will wet-hull them right away with a machine that is specially designed to handle semi-dry parchment. Hence the name; wet-hulling. These machines are very powerful and they can easily damage the beans. After the hulling, the unprotected bean is dried in the sun. If it’s a good processing station the bean will be dried in a clean area, but that’s not always the case with Indonesian coffee.
Coffee from the Indonesian islands Sumatra and Sulawesi are mostly wet hulled. On Java and Bali they tend to be washed.
Photo: Monsooned coffees swell up and take on a pale hue due to their unusual processing.
Monsooned Malabar Coffee
This is another dubious, rather old-fashioned processing technique that doesn’t get much love from the specialty coffee community.
The process take its name from the Malabar coast in India. Back in the days, it took months to ship coffee from India and back to Europe. During that time the beans would get exposed to all kinds of weather, among them the monsoon, and somehow they developed a unique flavor. As naval transportation improved, the trip suddenly became a lot shorter, and the customers complained that the coffee lacked the old ‘monsoon’ flavor. A new processing method was invented that aimed to replicate the conditions of the arduous journey from east to west.
The process begins by picking crops of beans and sun drying them in large barbecues. When they're dried, the beans are sorted into two graded piles and stored in a warehouse. You can have grade 'A' or grade 'AA.' Starting in June and going through September, the coffee beans are exposed to constant monsoon moisture through well-ventilated warehouses.
At this time, the coffee beans must be carefully turned and raked several times. This constant moisture exposure causes the beans to swell and eventually turn a pale gold color.
The moisture exposure leads to a very low pH level and for that reason most specialty coffee customers avoid this kind of coffee.
Kopi Luwak aka Civet coffee is well-known among most laymen. It has the reputation of being highly expensive and sought-after. But in fact this is just an urban legend. No real coffee lovers care for this literal ‘shit’ coffee and the price, while somewhat inflated compared to the abysmal cup quality, isn’t anywhere near that of panamanian Geisha.
Kopi Luwak involves feeding coffee cherries to a small weasel-like animal called the Asian Palm Civet. The cherries pass through the digestive system of the animal, but it doesn't digest the beans, and the producers are then able to collect them and wash them.
This process is highly controversial, and people would argue that it is animal abuse because the civets are often kept in battery cage systems, and the workers force-feed them the cherries.
Also, consider that most of the coffee being labeled kopi luwak is in fact just low grade commercial coffee, and you have plenty of good reasons to stay clear.
Photo: Let's keep coffee and weasels separate, shall we?
Coffee processing trends at competitions
Coffee competitions can be hard to understand for outsiders. While it would seem logical to most people that the “best coffee” deserves to win, it isn’t necessarily so.
At competitions a wide range of parameters are used to evaluate the baristas. So even though it’s important to showcase a great coffee, the presentation and the technique displayed by the baristas are equally important.
Nonetheless, it’s interesting to take a closer look at the latest years trends, and see if we can detect a pattern.
World Barista Championship*
Fully washed SL28 from Finca Las Brumas, El Salvador.
Washed Geisha, Finca Deborah, Panama
Washed/Natural Carbonic Maceration Sudan Rume, Las Nubes, Colombia
Honey typica, Costa Rica
Washed Caturra, Colombia, Huila
Honey (pulp natural) from Finca Soledad, Guatemala
Washed and natural Bourbon, Finca la Illusion, El Salvador
(*Only espresso beans have been included in this table)
At the most prestigious competition in the coffee world we see that washed coffees are still reigning supreme.
This isn't much of a surprise given that washed coffees are superior for espresso.
However, had we also counted the coffees that were used for cappuccinos, we would have seen more naturals.
Both naturals and honeys can add a delicate depth to milk based drinks.
World Brewers Cup
Natural-processed Geisha from Ninety Plus, Panama
Natural-processed Geisha from Ninety Plus, Panama
Natural-processed Nekisse heirloom from Ninety Plus, Ethiopia
Washed Geisha from Ninety Plus, Panama
Washed Geisha, Hacienda Esmeralda, Panama
Washed Geisha, Finca Santa, Panama
Keith o' Sullivan
Washed Caturra, Finca Bolinda, Bolivia
At the World Brewers Cup we can detect some very interesting trends.
A) If you want to win this competition you should use the variety geisha from Panama.
B) Don't be afraid to use naturals!
C) Get it from the company Ninety Plus!
While natural processed coffee isn't the best for espresso, it really shines when brewed in a pour over filter like the Hario V60.
Washed coffee dominated the first years of this competition, but the last three winners have all used naturals.
This is a clear indication that the world of specialty coffee has really started to embrace this kind of coffee.
It's also worth pointing out that in a competition situation it's important to have a coffee that stands out with bold notes.
Natural processed coffees beat both washed and honeys in this regard. Often they are very sweet and bold. Sometimes to the degree of being cloying. I could imagine that judges who only had to take a few sips would prefer naturals, but maybe the case would be different if they had to finish a whole cup.
Historically, the washed process has been seen as being superior to other processing methods. Partly, because it had a taste that was considered more 'clean', but also because it was efficient at sorting out unripe cherries or other defects.
This is about to change. Specialty coffee consumers, as well as the 'new' coffee markets in Asia, are looking for novel flavors, and this demand is met by innovative farmers, who are able to integrate agricultural science into their processing methods. This enables them to create interesting and complex lots without the risks inherent to dry processed coffee in the past.
This trend can also be observed at competitions such as the World Brewers Cup, where the last three consecutive winner have all opted for natural processed coffee.
Like there are different categories for wine; red, white and rosé, we'll probably also start to think about coffee in terms of the processing in the future.