I have been mulling over this question for a while; what really makes a cup of coffee
stand out from the rest? How do you determine its defining factor of quality? There
are so many things at play in what we have come to understand as quality, but I
really think we are still somewhat unsure of what it actually is. At many points in a
coffee cherry’s life, events occur that can produce (or take away from) quality. The
actual processing of the coffee is one of these defining moments. It is a fantastic
manipulator of flavour, and can be used to craft nuances that can only be unlocked
by skilled workers. I find the idea of changing flavour by tweaking the processing
absolutely fascinating! I want to take some time to dig a bit deeper into processing
methods around the globe. Each method is unique, developed for their particular
environment and each have a huge impact in the cup. It is kind of like a craft brewer
manipulating fermentation to produce different results.
Most of us are aware of the different methods of processing coffee, at least as far as
understanding natural, honey and washed process. If you need to brush up a little,
make sure you have a look here before reading further.
I intend to go a bit deeper than the cursory understanding and
look at the specifics for each country, the terminology and slight differences.
Brazil is one of my favorite origins, so it makes sense for me to start here; they have
such interesting and advanced techniques for harvesting and processing. The cutting
edge technology used on these farms is incomparable anywhere in the world.
A large part of what is done at farm level in Brazil is mechanised. Labour costs are
high and so much of this has developed out of necessity. Most of the harvest is
picked mechanically, or through using a method called strip picking, where the
branches are literally stripped of all their fruit. For someone who has only seen
selective picking, it can be quite jolting to see this treatment of the trees. You might
even argue that it is a shift away from specialty coffee, but at the end of the day, cup
quality does not lie.
The mindset in Brazil is to pick it all and sort it out later. Whereas the mindset of
specialty producers in Latin America (for example) is to only pick the ripe coffee, only
when it is at a perfect level of ripeness. It all makes sense when you start to dig
deeper into how they process their coffee. In small specialty producers outside of
Brazil, the technology to perfectly sort the cherries just does not exist.
Rather than pick perfectly ripe cherries between 19 and 23 brix (the amount of sugar
in the fruit) by hand, the Brazilians leave the fruit on the tree until it is closer to 23 all
the way to 30 brix, super sweet. So already we have the influence of a much riper
fruit. Typically the farm will time the harvesting to the day when each branch has
the least green fruit, and the dried pod cherries are not so aged they are
dropping to the ground, or moulding on the tree. This takes a pretty experienced
eye to work out; however, careful monitoring and years of practice have
perfected the technique.
In Brazil they have four types of processing: Natural (dry), pulped natural, semi-
washed, and washed. The majority of coffee is dry processed (or natural
processed); this is the traditional method that is still widely embraced in the
regions of Cerrado Mineiro and Mogiana Paulista, where harvest coincides with the
The term “Natural” came about as a way to differentiate the process from the
“Washed Milds” of Central America and Colombia. They wanted to have their own
term to use for marketing, and “unwashed” just didn’t fit well for them
(understandably). Ethiopia quickly took up the baton as well, but what we understand
as “Natural” in Brazil is not exactly the same as what we understand as “Natural” in
Ethiopia. In Brazil Natural refers to a harvesting style rather than a processing
method. There are a heap of factors that are different between Ethiopian Natural
and Brazil Natural. Most notably is the way it is picked, where coffee is allowed
to dry on the branch and fruit at all stage of ripeness are picked.
In Brazil, typically the coffee is laid out onto patios to dry, direct from the trees.
These cherry pods that are laid out to dry are called boia (ball) in Portuguese.
As I mentioned a bit earlier, all the coffee is picked no matter the level of
ripeness, so there is a high percentage of coffee on the patio that is over-ripe
and/or raisin like. Some of the more modern Brazilian farms force-separate the
coffee before it gets to the patio, reducing under-ripe cherries, which is of
course preferred from a quality standpoint. This force-separation is typically
done with a siphon system where the under-ripe cherries are floated off the
surface of a water tank. Other, less advanced farms, or ones with access to less
water just combine the lot, which is why you get so many quakers (under-ripes)
in Brazil natural process coffee.
Traditionally, dry processing is what produces the leather, tobacco, woody notes
we are likely familiar with in Brazilian coffee, rather than sweet, balanced fruit-
driven flavours of many modern Brazil Naturals. Dr Flavio Borem of Universidade
Federal de Lavras (UFLA) has done a lot of study into processing methods and
particularly natural processing methods. His theory on producing cup quality in
natural process coffee (typically understood as having poor cup quality) delves into
controlling metabolic changes in the drying process to preserve sweetness,
complexity and body. Controlling drying temperatures and drying rate maintains cell
structure integrity. Cell membranes are susceptible to damage in natural process
coffee and this damage can result in foul tastes in the cup. This stuff all gets a little
deep so if you want to educate yourself some more I suggest you head here
About 25 years ago the pulp natural process was introduced to Brazil by
Pinhalense, a well respected machinery manufacturer. Pulp Natural is probably the
second most popular processing method in Brazil. It is known as Cereja Descascado
in Brazil, 'Descascado' means 'removing the fruit skin' and Cereja means 'cherry’. In
Central America it is also known as ‘Honey Process’ or ‘Miel’. Pulp Natural is of
course made possible by some great equipment (championed by Pinhalense) called
demucilagers, which in essence promote a unique sweetness in the cup. Typically
the coffee is stripped of its skin in a pulping machine. Afterwards, the mucilage is
washed off to the desired level before being dried, completely skipping the
fermentation process that is used in other processing methods. Since a fair bit of
mucilage can still remain on the beans when they hit the drying process, Pulp
Naturals can only really be executed well in places with low humidity so they can dry
quickly, reducing the risk of moulding. Once dry the Pulp Natural coffee is placed in a
wooden box called Tulhas to rest and gain a more ‘settled’ taste.
Semi Washed (desmucilado or without mucilage) is a bit of a hybrid process that has
gone out of fashion because of an adverse association with Sumatran coffee (Giling
Basah). It is often confused as being one and the same as Pulp Natural processing
but I have come to understand it as being just a little different. It gives coffee a big
body and is generally quite sweet. It is a process that can go very wrong easily but
conversely can provide a lot of variation if executed correctly. This is where it all gets
a little confusing. The coffee is passed through a demucilager, which is set to take off
as much of the fruit as possible. In Central America, demucilagers used in this way
mechanically wash the coffee; hence you hear the term Mechanically Washed.
Since you can set these machines to remove pretty much all the fruit, you can end up
with some super clean coffee. Once again the fermentation step is skipped and the
coffee is sent straight to the patios to dry. Semi washed coffees that are dried quickly
under constant conditions for the most part taste cleaner and less muddled than
coffees that are dried slower, these can have more fruit in the cup and a more
muddled or hazy flavour. This goes back somewhat to the learning from Dr Flavio
The final processing method I must discuss here is of course washed process.
Recently, coffee producers have been showing an interest in producing washed
coffee, but demand is still lacking in national and international markets. This is likely
in part because of the poor reputation for quality that Brazilian coffee has held for
such a long time, but also because of the lack of washed coffee in the first place in
Brazil. Washed coffee is pretty much the same as the semi-washed process except
this time the coffee is fermented to help remove the mucilage. Typically this process
cleans up the cup profile and brings out acidity.
So that is Brazilian coffee processing in a nutshell, sort of. Once the cherries are
reduced down to parchment coffee, more sorting has to happen to make sure the
final product is speciality quality. The parchment coffee is typically taken from the
farm to a dry mill, where the coffee is prepared for export. Once the coffee is
received it is run through density sorting, a large flat bed that, through vibration,
separates out coffee based on density. Density can be used as a great indication of
quality. It is then run through a cleaning process and is finally sent to the colour
sorter before export. The colour sorter is a machine with a tiny laser that inspects
each bean for blemishes. So as you can see, sorting is all mechanized in Brazil. Not
only does this present you with a much better cup quality (machines make less
mistakes than people), but it also alleviates the in-country problem of high wages.
— Lucy Ward