Coffee Processing Methods

If you’re new to the world of specialty coffee and you’ve peeked through the looking glass at what coffees are out there, one of the first things you’ll notice is the ‘processing method’. Career baristas and roasters are all too familiar with these different terms and it can be a little daunting on your first approach - I vividly remember scratching my head at the overwhelming choices that are out there. 

Here at Django Coffee, we want you to feel relaxed and more informed about your choices; therefore we have compiled a short post about the main processing methods, where they originate from, and what that might mean for you in the cup. So let’s dive in!

Processing refers to the way in which coffee is prepared at source; taken from its raw form (the fruit on a coffee plant) and magically transformed into the green bean ready for roasting. How does it get there you ask? Well this all depends on location, altitude, farm and much more. Nonetheless, we can safely say that it’ll fall into one of three well known categories (and maybe a few more experimental ones).

 (The coffee plant with the beautiful ripened cherries awaiting processing – this initial step requires a lot time and patience, as cherries ripen at different stages, requiring a skilled and trained high to select the best quality fruits at the right time).

Natural (Dry Processed) coffees are dried in the full cherry which allows fermentation to occur; this encourages the reaction between the natural sugars and the seed - following this, they are washed and dried further. This method is seen, normally, in hotter climates with less rainfall and is believed to be the first method of coffee processing. This allows farmers in more arid locations produce their crop and still send out delicious coffee beans ready for the UK market. It produces the often tropical, sweet characteristics typical with this method. They are often a more lavish coffee - some like them, some don’t, as they are normally stronger and more pungent in taste. Here at Django, we love the naturals; they highlight the source and provide a means of showing off what each origin and location has to offer. As these types of coffee are divisive, you won’t find them much on the high street. 

 

Washed coffees are normally prized for their clean and vibrant notes; initially the seeds are removed from their cherries by passing those juicy fruits through a mill. This crushes the outer haul, leaving the raw beans separated for the next step. From here, they are transported into large tanks, allowed to float to remove any remaining sugars and pectins that remained on the seeds. Following this, they are then dried in the sun on large raised beds.

 (The green beans drying in the sun – these beds are raked on schedule to prevent mould formation. These are often raised to increase air flow).

 As the cherry is removed early, this reduces the exposure to the natural sugars, a contrast to the aforementioned naturals. This method is more forgiving and often what you’ll find in your local specialty shops. As a coffee newcomer, this is a great choice to expose the true coffee experience and indulge in the sweet, juiciness that Django and our customers love.

Thirdly, there’s honey processing. This is often seen as a hybrid of the washed and natural methods, as the coffee seeds are removed from the cherries with the same mill as discussed earlier, but allowed to dry without washing. This leaves mucilage which is sticky and golden in colour, hence the ‘honey’. As the golden hue oxidises and dries, it changes from Yellow to Red to Black - also terms you will hear in specialty coffee.  Dependent on the time it is allowed to dry, or the amount of mucilage left on the seeds, this influences the flavour of the final cup and is often a decision made by the farmers. Honey processing requires less water and may be seen as another easier processing method; however, due to the heightened chances of mould production and the laborious task of turning and airing the beans, this often is a more complex process and can reflect in price. Final cups taste noticeably fruitier and ‘sweeter’ similar to that of the naturals, but with a level of acidity that offers its consumers a rounded clarity.

As coffee has transformed and a new birth of specialty coffee has emerged, we have seen the development of a few - let’s say more peculiar - processing methods. There is a growing desire amongst coffee professionals to exceed the boundaries of what is currently available; to impart more and more flavour and unique, quirky characteristics that transports the consumer into a completely new experience. Anaerobic Fermentation and Carbonic Maceration processing are the two ‘kids on the block’ that have recently achieved this. Let’s have a look what this means:

 

To discuss how this works, we really need to talk about fermentation and what it is all about. Fermentation, as discussed earlier, has been utilised across the world for centuries to bump up the ‘funkiness’ and bring a bolder flavour to what we eat and drink. Although all coffees will experience some form of fermentation, anaerobic stands alone as it is performed ‘without oxygen’. To accomplish this, farmers typically pulp the fruits (as usual) but then transfer the remaining mucilage and parchment into large airtight tanks. These tanks are sealed for extended periods of time and fitted with a one way valve, to allow gasses to release and microbial life to flourish. 

As oxygen is a necessity for the vast majority of living organisms, what cultivates inside those stainless steel tanks normally takes the form as yeast, which transfuses the flavours unique to this processing method. This is also more specifically known as maceration, which relates to the metabolism seen by these little organisms. Here at Django, we recently released our Insight coffees, which have highlighted some fantastic flavours produced by maceration. The first instalment from October 2020, underwent a 72 hour maceration process as described above - the outcome produced highly expressive flavours of tamarind, deep floral qualities and a cider-like crispness. Although less available on the current market (due to the high risk of product loss and extensive labour needed from the farmer), we definitely recommend trying Anaerobic Fermentation coffees - keep your eyes peeled on our website for more in future!

 

Carbonic maceration is very similar to anaerobic fermentation, however the cherries are left intact when entering the sealed tanks and carbon dioxide is introduced into the barrels; as the cherries are left while, this increases the length in which they must ferment, usually needing weeks of tending and nurturing from the farmers. 

 

Over this period of time, some interesting observations can be seen within the tanks - gravity takes its toll and presses the cherries towards the bottom, opening up the skins and increasing the rate of fermentation. This is a stark contrast to those cherries at the top which will take longer to macerate; it is this contrast that produces extremely fruity, full bodied and ‘wine like’ characteristics within the coffee. Like its anaerobic counterpart, the carbonic maceration process is highly experimental and is seen much less frequently within the market. This is something we are really excited to bring to everyone here in the UK within the near future.

Coffee processing is always changing and transforming, and as the world of specialty coffee expands, we bear witness to the amazing innovative techniques that coffee farmers are adopting all around to provide us with our daily dose of coffee. It is an integral part of coffee production that the coffee consumer often (and unfortunately) has never been exposed to. Nonetheless, we hope that now we can provide some insight to what those confusing labels actually mean and the next time you’re ordering your favourite Django coffees, you’ll know what to expect in the cup.