The coffee jargon keeps growing and growing, as well as the confusion all of these terms create in everyone's heads. I often get asked about the difference between some of the coffee processing methods, so I thought of writing a little bit about it and hopefully clear up the confusion bit.
Let's start at the very beginning, when coffee was first discovered........ nah - probably unnecessary.
I'll start explaining what coffee processing is and go from there.
above: Ethiopian green beans that have gone through the natural processing method.
Why and when are coffees processed?
Coffee beans are the seeds of the coffee cherry. Each of the cherries have 2 seeds (there's an exception to that - I'll cover that later). The seeds need to be removed from the cherry, cleaned and dried before they are ready to be roasted and end up in a nice cup of coffee that you will enjoy so much.
The terms you see in the title refer to the method the coffee seeds are removed from the coffee cherry and prepared before they are ready to be bagged and shipped across the world to be roasted.
I'll try to succinctly cover the most common ones.
The Natural process
In the natural process, after harvested, the coffee cherries are laid on drying beds for about 3 weeks, regularly turned/mixed to allow homogeneous drying and avoid bad things such as mold to grow.
Once the cherries are dry, the coffee cherries go through a machine that removes the skin and the dried mucilage, exposing the coffee beans, which are then stored.
This process is believed to be the oldest coffee process. It adds fruit flavours to the coffee beans, mostly resembling berries and cherry and is loved by some and hated by others. For that reason, these coffees normally will result in a more enjoyable experience as a single origin if you have them black as pour over or espresso. In a blend, they will go really well in milk based drinks adding extra sweetness to the cup.
I'm one of those that love the wild flavours that natural and honey processing coffees bring.
The natural process is predominant in Ethiopia and Brazil.
The Washed process
The main processing difference between the natural and the washed processes is that before the coffee is dried, it goes through a de-pulping machine to remove the skin and cherry mucilage and then to a washing tank where the beans ferment for a day or so and in the process the remaining mucilage is removed by the fermentation process itself. The seeds are then washed, resulting in a much cleaner bean.
Once that's completed, the coffee is laid in drying beds, and regularly turned to ensure homogenous drying or dried by drying machines.
This process brings a bright acidity to coffees and clean notes, so you'll be able to identify the flavour notes from the origin a bit better.
The Honey process
The honey process is somehow similar to the natural process, however in this process, the coffee cherry skin is removed along with a degree of the mucilage (I'll expand on this a bit further). The coffee is then placed in drying bed to dry and ferment. By the way - there's no actual bee honey involved in this process.
When I referred to "a degree of mucilage", I meant that there are 3 main degrees of mucilage that are left stuck to the beans and they result in more or less intense fermentation and fruitiness and booziness in the flavour of the coffee.
Yellow Honey - the coffee is left with some mucilage
Red Honey - the beans are left to dry with more mucilage than the yellow honey
Black Honey - only the skin is removed and majority of the mucilage is left attached to the beans
The one above are called yellow, red and black because of the colour the mucilage leaves the bean with once dried.
The process that I described above are the more traditional processes.
There are other three processes that are becoming more and more popular lately amongst specialty coffee community and worth mentioning are the extended fermentation and the carbonic maceration and the anaerobic.
Extended Fermentation - This process is a subset of the washed coffees, where the beans are left to ferment longer than the normal day or so. This process requires closer monitoring because it can ruin the coffee if not managed properly - the longer the coffee is left in the fermentation tanks, the higher the risk is to ruin it. Once it's fermented, it is washed and dried.
Carbonic Maceration - An interesting process where the coffee cherries are placed with the skin in a stainless steel drum, sealed and injected with CO2 to ferment. The cherries ferment within themselves, sealed by their own skin and in the presence of CO2. This is a process that is traditionally used in winemaking. Certainly an interesting process, which results in guess - winey notes, banana and some other interesting notes.
Anaerobic - This is a washed process where the fermentation phase is done in sealed, oxygen free containers. The coffee will be fermented in a different micro-organism environment due to the lack of oxygen, which results in a different flavour profile. This process is a more stable process than the the fermentation in the presence of oxygen.
Countries in Central and South America have been experimenting heavily with these alternative methods and getting excellent results.
We often keep in stock coffees covering most of the processes I explained above. If you'd like to try some of these different processing methods, head to our products page and check what we have on offer.
If you have any questions, please shoot us a message and we'll try to answer as quick as possible.