Coffee processing in Indian Specialty Coffee

Coffee processing in Indian Specialty Coffee

In simple terms, it refers to the way that a seed is removed from a coffee cherry which will eventually change the sweetness, body, and acidity of brewed coffee.

It basically makes specialty coffee even more special.

But it aint as simple as it sounds. Because coffee processing is an equally important step just like the roasting that helps develop the unique flavour profile that we all enjoy today. 

There are some traditional methods we know and might have heard of, but there are now some new age methods that result in the complex flavours that we all enjoy in this third wave of coffee.  

Coffee processing revolves around Fermentation. The oldest method in coffee processing. And as the definition suggests, It's the chemical breakdown of a substance by bacteria, yeasts, or other microorganisms. 

But fermentation is not necessary and not all coffee is fermented. Also not a necessary step in coffee production. 

Anyways, we will discuss all the processing methods briefly as we progress. 

So, the broad categories we will cover today, include: 

  1. How does coffee processing happen?
  2. Why is it needed ?
  3. Different types of it ?
  4. How speciality coffee thrives on its processing 
  5. How the end result is not always as desired 

Let's first understand what processing is and why it is important. 

Why do we need coffee processing at all?

Basically as we discussed in our 1st episode, the cherry that grows on the coffee shrub needs to be hand picked and then requires processing to separate the bean and the cherry. 

Each coffee cherry consists of layers. These include: outer skin, pulp, pectin layer, parchment, and silverskin – the last layer is the one that surrounds two coffee beans locked inside. The goal of processing is to get rid of these layers and get to the essence of the product, and then to dry the bean to the optimal level.

However, many desirable, interesting flavors come from the fruit, juice or pulp, and not from the seed itself. And that is why processing is such a crucial and essential task when it comes to specialty coffee.

There are many ways to get rid of layers. Each method will significantly impact the final taste of the brew that you pour and enjoy.

The 3 most common processes include:

  • Washed Process (Also known as wet method)
  • Honey processed with 3 subtypes (Also known as semi-dry method)
  • Natural (Also known as dry method)

I would like to share a quick flashback story of my visit to the farms back in February earlier this year. 

So basically I visited farms or estates as we call them and the experience was surreal. So knowing coffee processing in theory and having just heard about it to what I witnessed and perceived was worlds apart. 

Firstly, the sweet candy-like smell is all over the coffee plantation and you can sniff it from meters away. The lush green hill tops and the whole balanced ecosystem surrounding it is mesmerizing. 

Secondly, when processing is taking place you will see all the coffee at one place being dried out in the open or on raised beds or being washed or fermented in tanks. The whole process is itself an art and the outcome of hard labour pays off during this process. 

I still remember the smell, the dried fruit, the milling stations packed with green beans and the overall rush caused because of dispatch and deliveries. Can't wait to be back in the fields come harvest season of 2022 where our radical coffee processing ideas will come to life.

In anycase coming back to the processing methods.

Let us go one by one and discuss them all briefly. 

We shall start with the most common and treasured ones to begin with. 


This particular method will develop deep fruit flavours in your cup. 

This is actually the oldest processing method. In this process, the fruit is dried first out in the field or on raised beds first and the layers are removed in step two.

The harvested fruit is dried entirely in the sun, making sure it’s evenly spread and regularly turned. Once the moisture level is accurate and when the fruit looks more like a raisin than, the bean is separated from other layers.

Resulting outcomes will be :

  1. High in sweetness
  2. Will have characteristics of ripe fruits like strawberries and blueberries
  3. Non-Dominant acidity
  4. Rich and med-heavy Body

To give you an idea, the Biccode Estate SC - 42 in our store is a perfect example of naturals. 

Sweet, berry-like and heavy on the body. 


Beans processed in this method are perceived as cleaner, more transparent and complex in taste, with lighter bodies. 

The ripe fruit, as we know the cherries, are passed through the depulper, a machine that separates the seed from the flesh. 

The machine does its job, but a lot of the pulp still remains on the surface of the seed. For this reason, the seeds are then thrown into water, where they are washed and the remaining layer falls off the bean. The beans also undergo fermentation as they are left in water for long. Now depending on the technique, for eg: the Double Fermented Washed coffee “Mango in loop” in our store, the coffees under different combinations of how many times will they be washed to how many hours or days they will be fermented. The coffee is then taken out of the water and dried in the sun or in the shade until it reaches the final stage, called milling. 

But more about that later in this episode. 


Here the coffees developed are with light fruit flavor notes.

This method falls in between naturals and the washed process. The biggest difference here is that the cherry is depulped and not directly dired, the cherry is depulped but not directly added to water instead the beans are directly put out to dry. Which means the depulped beans with a little pup still intact are left out in the sun or shade to dry. 

The amount of the initial amount of pulp stuck to the bean will have a significant impact on the taste of the coffee and also determine the sub-type as discussed before. So basically less pulp refers to white honey processed coffee, somewhere more is referred to as a red honey processed (For eg. the Karadykan Estate - 3 A coffee in our store) and lastly the most of pulp means Black Honey processed coffee. The no. of hours coffee's left to dry completely depends on the plantation or roasters like us who are involved in coffee processing. 

The outcome of such process will lead to:

  1. No deep, mature fruitiness characteristic of naturals
  2. Acidity not as dominant as in washed coffees, but often marked more clearly than in naturals.

Apart from the common processes there are some uncommon ones that are now regularly being practiced by many plantations for half a decade now. 

Anaerobic fermentation

In biological terms, the word anaerobic stands for, relating to or requiring an absence of free oxygen. 

So in this method, the cherries are thrown into the de-pulper. The separated seeds are then placed in airtight fermentation tanks. The pulp and parts of the fruit that were obtained separately from de-pulping are also added. The tank is then sealed and oxygen is sucked out. The process takes approximately twenty hours, but then again increasing or decreasing the time depends on the planter's tried and tested method. During this time, the pressure in the tank increases due to the carbon dioxide produced during the fermentation. Its level as well as sugar level, temperature and pH are meticulously measured to produce optimum results. 

And by the way if you are wondering, then (pH is a measure of how acidic/basic water is. The range goes from 0 - 14, with 7 being neutral. pHs of less than 7 indicate acidity)

The basic technique here is to “push” substances from the juice and pulp into the beans using the high pressure in the tank.

BTW, anaerobic natural fermentation also called as anaerobic naturals (Like the Gungegiri Estate - 40 A on our store) is a sub-type of this process where in the cherry is put in as whole in the tank and the rest of the process is carried out the same way. 

An outcome of this process will lead to:

  1. Creamy, silky texture
  2. Complex and interesting acidity
  3. Floral Notes 

Lactic process:

Processing also takes place under anaerobic conditions, but the fermentation environment takes place with lactic acid bacteria cultures. The bacteria feed on the sugar contained in the pulp, which produces lactic acid. PH measurement is especially important in this case. At the right moment, fermentation is stopped and the beans are soaked in clean water to stop the growth of bacteria. The last step is drying, as other common processing methods.

Carbonic maceration

It is also an anaerobic process. The whole ripe fruit is placed in an airtight tank. The tank is closed, then carbon dioxide is forced into it, which, as a gas heavier and denser than oxygen, “pushes” oxygen out  through a special valve. Many chemical reactions take place there, the products of which are responsible for the original, unusual taste of the coffee processed in this way.

Then the beans are processed using either a dry or wet process depending on the final method, techniques and as per the outcome desired by the producer. 

The outcome leads to: 

Interesting taste characteristics such as: ripe strawberries, cherries and raspberries, notes of banana or bubble gum and more.

Wet hulled coffee,

It is also known as the semi-washed coffee process. During this processing method, depulping machines remove the seeds from the cherries. However, rather than moving them to drying beds, the cherries get stored in plastic tanks. The mucilage also remains on the seeds, and much moisture is retained. They then go through a process called hulling to remove it, along with parchment (the dry flakes covering a bean) that surrounds the seeds, and laid out to dry afterwards.

So, that was an insight into different processing techniques which included the common ones and the new ones we might have heard of and tried in this third wave of coffee. 

But there are more not so common processes that are now being adapted across the globe.

The only issue with trying something new is that it incurs a lot of expense and you never know if the desirable outcome will be developed or not. 

So if those were some methods you have heard of or even tried from a coffee roaster, then wait there's more. 


In comes the experimental coffee processing realm. A place where we at like to be and do not shy away from. 

There are processes which are being tried and tested as we speak and many yet to be tried. 

A few of them include: 

  1. Frozen coffee
  2. Yeast processing 
  3. Dark room coffee
  4. Static cherry coffee
  5. Mountain Water Process

We ain't gonna deep dive into these as of today, but a topic for another day and most certainly processes you will soon be able to try out from

Keeping in mind that barrel aged coffees and fruit processed aren't exactly processing methods, but actually add-ons to the whole processing.  

Also coffee with added syrups or flavours definitely do not fall under coffee processing and also not considered to be specialty coffee. 

After one chooses the processing method and concludes the same, the journey of milling actually begins. An integral part of the whole process as the final product can only be procured post milling and not before as it is not ready to be roasted and of course brewed. 

The coffee dry mill is one of the last stops on the journey your coffee takes as a part of the cherry to bean journey. This is where this journey ends.

So basically it involves many stages. As specialty coffee of the highest quality 2-3 more steps are added in this process to achieve better results.

In a nutshell in a dry mill, the beans go through final cleaning, polishing, sorting, and grading.

Let us talk about these in brief. 

Step 1 : Pre-cleaner

The pre-cleaner is simply a vacuum that sucks any fibers (such as the leftovers from jute bags) or dirt away from the coffee. 

Then comes the magnet. This is quite a simple part of the machine. As the coffee beans move past the magnet on a vibrating belt, it takes out any magnetic metallic impurities. 

Destoner: Now that the coffee is free of light impurities and metallic impurities, it moves to the destoner. Here, vibrations separate the coffee from any small stones that hide among the coffee beans.

The second step includes the huller. It removes the parchment surrounding the coffee beans and reveals the green bean.Now, even if the coffee has been through a huller, there is a chance that dried parchment or mucilage may still cling to the bean in small amounts. In the 3rd step the polisher removes any residue leftovers from the huller.

Eventually, grading by size, color and weight is done to differentiate coffees. 

In the end, another round of sorting is done, but this time by hand. Steps like these make specialty coffee truly special as they emphasize on quality first. 

So this is it. That concludes our today’s episode focused on specialty coffee processing. 

A crucial step in the life cycle of coffee development before it reaches you. A step we at grey ousl coffee emphasize on and thus have planned plenty of experimental methods come harvest season in 2022. 

Can't wait to try them out and wait to share them with you all the listeners. 

Because we at grey soul coffee are just getting started ! 

So to drink or make better coffee, we usually use a different equipment or maybe us roasters use our skill to roast it differently, but it's not just about the bean and also about the fruit. And that is exactly what we have learned today I guess.  

Because focus not only has to be on the bean but also the fruit. 

Technically coffee is a fruit, so growing it better and processing it better will result in a much better cup of coffee. 

So coffee is a fruit but what we are drinking ultimately is the seed. 

In the end, having a good cup of coffee in itself is a miracle. Because it goes through so much before reaching you that having the same coffee each year, even if the farm remains constant is highly unlikely. It's a long chain of events with a lot of people involved. At the end of the day, it is a fruit and ergo an agricultural product that depends on many factors controlled by nature. 

Hope this provides you a little insight into specialty coffee processing and as always i believe you are leaving this episode with knowing your coffee better.

As always, keep brewing, enjoy your coffee and the rare experience it brings along.

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