What is in a coffee process?
Did you know coffee goes through a unique processing method?
In our previous blogs and videos, we have covered how to read a coffee label or what the various coffee roast levels are like, but at the end of the day, inherently there is still a factor of coffee that shines through despite its various roast profiles out there. That is the process that the coffee goes through, processing coffee so separating the coffee cherry’s fruit flesh and skin from the coffee beans is one of the most crucial aspects of farming coffee. How coffee is processed can have a dramatic effect on the resulting cup and nowadays roasters and baristas are concentrating on coffee processing to describe the coffee. Also, lately it has become more and more popular that the farmers have started to experiment with new coffee processing methods such as anaerobic fermentation.
Let’s go through the most common coffee processing methods. The goal of processing coffee for farmers is to separate the bean from the coffee cherry but also preserve the coffee’s value. Even if the coffee picked is perfectly ripe and the harvest was excellent, a bad coffee processing can lead to defects which will in the end decrease the value of the coffee. Some processing methods will require more time, investment as well as natural resources. So choosing the right processing method can be crucial decision for a coffee farmer or producer.
Natural (Dry Process)
Also known as the dry process, natural processing is one of the most old school ways or known to others as the most back to basics way to process coffee. After picking the coffee cherries, they are then typically spread out in thin layers to dry in the sun. The drying stations, is what it is called, are a little different depending on the farm or region; some places use brick patios, others use special raised beds or tables which enable air to flow around the cherries from the bottom up, thus an even more even drying.
To avoid the build up of mould, fermentation or rotting, the cherries are turned regularly. Once the cherries are properly dry, the skin and dried fruit flesh (Cascara) are removed mechanically and the green coffee is stored and “rested” before exporting it.
Although this method needs less investment in regards to financial investments, it still requires certain climatic conditions to ensure the drying of the fruit and seed in time. This process is commonly found in countries such as Ethiopia and Brazil as these regions are commonly known to not have big development over time.
Common flavour notes for naturally processed coffees include blueberries, strawberries, tropical fruits and honey to name a few. On the other hand, there can be flavours of the other end of the spectrum as well such as fermenty notes, alcohol like notes, which often described as wine like flavour notes which oftentimes is compared to coffees of the Washed Process.
Washed (Wet Process)
Also known as the wet processing method, is one of the other main ways to process coffee. In the washed processing method, the flesh of the coffee is removed mechanically from the coffee bean before the beans are laid out to dry. Removing the flesh is often done with a machine called depulper and after the depulping of the beans, the beans are then put into a water tank where the fermentation process will remove the remainder of the fruit flesh.
The amount of time that the fermentation requires depends on the climate and altitude. In a hotter region, the fermentation will take less time and vice versa for if it is in a less hot region. Usually the fermentation is between 24-72 hours and if the coffee beans are fermented for too long, it will have a negative effect on the flavor of the coffee. After the fermentation is ready, the coffee beans are then washed to remove any leftover flesh and is then layed out to dry. Drying in the washed process is done similarly as in natural process so in brick patios or raised beds. To ensure even drying, the beans are turned regularly as per the natural process. The beans may also be dried mechanically with the use of machinery, especially in regions where there isn't enough sun or humidity.
Washed coffees often lead to bright and acidic flavors in the cup. It's commonly widely appreciated by both roasters and baristas due to it’s increased complexity and cleaner cup profiles. Many would describe washed coffees to have white wine like flavors when compared to say a naturally processed coffee. Some would argue that this is because washed coffee often highlights the true character of a single origin like no other process which is why you would find it in most specialty coffee shops and roasteries.
When done right, washed processed coffees can reduce the risk of defects and it's a more stable way to process coffee. On the other hand, it will require more water than any other processing method, so it's more expensive for the farmers or producers when sourcing and purchasing.
HONEY (PULPED NATURAL PROCESS)
The honey process, also known as the pulped natural or the hybrid process, is used commonly in the Central American countries such as Costa Rica and El Salvador. The cherries are mechanically depulped but the depulping machines are set to leave a specific amount of flesh on the beans. After which the beans will go straight to the drying tables or patios to dry. As there is less flesh surrounding the beans, the risk of over-fermentation is lower as compared to the natural process but the overall still has a delicious sweetness and body in the cup as the sugar levels will increase due to the remaining flesh on the seed. When done well, honey processed coffee has positive attributes from both a washed and natural processed coffee; which are the sweetness of naturals and brightness of washed.
In recent years, subcategories within the honey process have developed and they are yellow, red, golden, black, and white honey. This reflects the ability this process has to influence the taste and overall profile of a coffee. It can become a highly scientific process, as the level of mucilage – which influences the sweetness and depth of body of the coffee – is monitored and controlled. Typically, the more mucilage left on the bean, the sweeter the taste.
Other coffee processing methods
Anaerobic fermentation is one of the newest methods in processing coffee and it has gotten popular especially among really high end coffee such as competition coffees. This is because the anaerobic processed coffees are very much similar to washed coffees however the fermentation of the coffee is done in a fully sealed - oxygen deprived tank. As this method is very much still in its infancy stage due to the constant experiments, oftentimes it is deemed to be wild, unexpected and full of complex flavours.
Carbonic MacerationThe method is similar to the anaerobic process. This method was and is a copy of how wine producers process their coffees within the wine processing world. The main difference between the two is pretty much the coffee cherries are fermented whole within its barrel. It is because of that, that it’s flesh will go through a winey process and it then imparts its delicious flavour notes within the coffee seed itself. As a result, with its incredible fermentation process of the coffee flesh and it’s pressure built within the barrel, one would often find flavours of red wine, whisky, bananas’ and bubblegum to name a few
How do producers decide what processing method to use?
Most coffee producers will want to produce the most profitable and the best-tasting coffee possible, but when their environment limits them, it comes as a challenge altogether. Coffee, more often than most, has a very close bond to its surrounding environment.
Oftentimes, coffee producers will wait to see how much rain has fallen before deciding on whether to produce washed, honey, or natural coffees. This is because heavy rain will make it harder to produce good natural process as coffee cherries can start splitting. If it hasn’t rained then that means the conditions are great for honey or natural processing because no sugars will get washed away.
At the end
Coffee is a very subjective food stuff, and because of such, it is not something that will suit the entire world with just one bean. With more and more unique techniques or unique environments come into play, coffee which was once deemed to be of a particular type or expectation will completely blow your mind. Example would be that one would expect typical chocolate and nutty notes from a Brazil single origin, but instead you would find something like a flavour profile of Vanilla, Papaya and Cashew, who would have thought?!
So trust your palette, and explore what coffee has to offer, as one man’s trash is another man’s treasure, you’d be surprised to see what kind of coffee you'll find interesting with the various types of processing methods out there.