What are processing methods?
Have you ever looked at a bag of coffee and wondered what the heck 'Washed' meant? Or 'Natural'?
Does this description mean that other coffees are dirty, or synthetic?
Luckily, it doesn't! These are simply processing methods that coffee goes through at the farm level. So let's break down what these terms mean, how they affect the coffee, and why it has to be done in the first place.
Why
Why is it done? Why is it important? To understand that, you should know that coffee is a tree. If left unattended, these trees can grow as high as 40ft, but most farmers keep them around 6-8ft tall so it is easier to harvest. Specialty grade coffee (meaning the good stuff) is all harvested by human hands, picked at it's peak of ripeness. They aren't picking bean pods, but cherries! Inside each coffee cherry lies two seeds (beans), and they are covered in fruit and juice. However, we only roast the seeds, so they have to process them to not only remove the fruit, but also quality check the coffee so no defects leave the farm. This is done differently from farm to farm, and from country to country, but no matter how it's done the result is green coffee that we roast, and you enjoy. Now that we got that out of the way, let's get more specific.
Natural
The Natural processing method is a traditional method of processing coffee beans where the cherries are left to dry with the fruit intact. The cherries are spread out in a single layer, either on raised beds or patios, and are left to dry under the sun. The cherries are occasionally raked to ensure even drying and to prevent mold growth. The drying process can take up to several weeks, depending on the weather conditions, and the cherries are often covered during the hottest part of the day to prevent sunburn. Once the cherries have dried to a moisture content of 11-12%, they are hulled to reveal the green coffee beans, which are then sorted by hand or machine to remove any imperfections. The natural processing method is known for producing a sweet and fruity coffee, with a heavy body and low acidity, due to the fermentation that occurs during the drying process. However, this method also has a higher risk of producing inconsistent results, as the beans can be affected by mold or over-fermentation if not properly dried.
Washed
The process begins with the removal of the coffee cherry's outer layer, known as the mucilage, which is accomplished through a pulping machine. The coffee beans are then fermented for 12 to 48 hours to break down the remaining pulp and remove any remaining mucilage. Next, the coffee beans are rinsed thoroughly to remove any remaining impurities and dried, either through sun-drying or mechanical drying. The coffee beans are then sorted according to size and weight, and the dried coffee parchment is removed to reveal the green coffee beans. This washed processing method results in a clean, bright, and balanced cup of coffee with a distinct acidity and well-defined flavors. This method is widely used because it is a cost-effective method that results in a consistent and high-quality product.
Honey
In this method, the fruit pulp is partially removed from the coffee cherry, but the mucilage (the sticky layer surrounding the coffee bean) is left intact. The coffee beans are then dried with the mucilage still attached. The amount of mucilage left on the beans varies from trace amounts to a substantial layer, which results in different levels of sweetness, body, and acidity in the final coffee. This process provides a unique taste profile compared to other processing methods, with a balance between fruitiness, sweetness, and body. The beans are dried on raised beds, patios, or other surfaces for several days to weeks, depending on the desired flavor profile. The Honey Processing Method is named after the honey-like appearance of the mucilage on the dried coffee beans. The levels of honey processing vary in the amount of mucilage that is left on the coffee beans during the drying process.
Yellow honey process: The least amount of mucilage is left on the beans, and the coffee is dried until the parchment layer is dried and the beans have a yellowish appearance.
Red honey process: The medium level of mucilage is left on the beans, and the coffee is dried until the parchment layer is dried and the beans have a reddish appearance.
Black honey process: The most amount of mucilage is left on the beans, and the coffee is dried until the parchment layer is dried and the beans have a black appearance. This level of honey processing results in a heavy body and rich flavor profile.
Anaerobic
Anaerobic Processing is a method of processing coffee beans that involves fermenting the cherries in a sealed environment with limited or no access to oxygen. This process is typically carried out in closed tanks or sealed containers and involves controlling the temperature and time of fermentation to achieve specific flavor profiles. The anaerobic process can result in a unique and complex taste, often with notes of fruit, wine, and chocolate, depending on the level of fermentation and the type of coffee beans used.
Lactic Acid
The Lactic Acid Processing method is a unique coffee processing method that utilizes bacteria, yeast, and lactic acid to ferment the coffee cherries, before the beans are removed from the cherries and dried. The process takes place in an oxygen-free environment, which allows for a slow and controlled fermentation. This method results in a coffee that has a unique, complex flavor profile, with notes of fruit, floral, and a tangy or sour taste. The lactic acid fermentation process often results in a low-acidity coffee, and can also help to reduce bitterness in the final cup.
Carbonic Maceration
Carbonic Maceration is a unique coffee processing method that is used to produce fruity, sweet, and light-bodied coffee. This method is a variation of the traditional fermentation process and involves leaving the coffee cherries whole and intact while they undergo fermentation. Instead of using yeast to initiate the fermentation process, carbon dioxide is introduced into the closed containers where the cherries are kept. This creates anaerobic conditions and triggers the breakdown of the cherries' sugars into alcohol and lactic acid. The carbon dioxide helps to preserve the cherries' fruity and floral flavors, and the resulting coffee is often described as having notes of berries, cherries, and wine. The carbonic maceration process typically takes several days, and the resulting coffee is usually washed and dried before being roasted.
Koji
Koji processing is a unique method of coffee processing where the coffee cherries are fermented using a fungus called Aspergillus Oryzae, also known as Koji fungus. The cherries are placed in a controlled environment along with the Koji fungus and left to ferment for several days. During this time, the fungus breaks down the sugar in the cherries and produces lactic acid, acetic acid, and ethanol. This process contributes to a change in the coffee's flavor, aroma, and acidity levels.
The result is a coffee with distinct and complex flavors, often described as having fruity, floral, or wine-like notes. The koji processing method is relatively new and is still being experimented with by specialty coffee producers. It is considered a challenging and demanding process that requires precise control of temperature, humidity, and other environmental factors.
