Overview of the wet processing in Coffee processing
In today’s world, the word “processed” is frequently associated with negative connotations, particularly in the food and beverage business. We’ve come to associate it with chemicals, fast food, and other unhealthy foods. In coffee, however, this is totally “natural.”
Coffee is the seed of a berry, the coffee berry, which we prepare and consume every day (of course). This means that the first thing we must do after harvesting removes the pods from the beans to obtain coffee – but this is easier said than done.
The outer shell (also known as the pulp or exocarp), followed by the mesoderm (also known as Mucilage, mesocarp), a slimy layer responsible for most of the sweetness of coffee; a hard shell that covers the seed (also known as a husk); and the silver shell, a thin film that coats the coffee beans.
The removal of these layers of fruit is the goal of coffee processing. There are various methods for doing so, each impacting the coffee’s flavor.
Two things must happen between harvest and storage: the cherries must be peeled, and the kernels must be dried to the required degree. The fundamental distinction between coffee processing procedures is the order in which they take place.
Suppose the dry processing method consists of merely drying the coffee cherries in the sun and then crushing the beans to separate them. Then, in the wet brewing method, a portion of the coffee cherries is removed after selecting (the outer peel and sometimes part of the Mucilage), followed by the remainder (which includes the kernel and part of the sticky mucus).
Soaking to ferment After the coffee has been fermented for some time, the mucus may be rinsed away, and the coffee can be dried. That’s why it’s referred to as “wet technique” or “wash.”
Wet coffee processing in Coffee Process
Although there are differences in the method used in different nations, the wet processing procedure always follows the same four steps: Sorting > Peeling > Mucus removal fermentation > and Drying or drying into products.
The wet processing method necessitates specialist equipment and a large amount of water. If done correctly, the quality of the beans is improved, and green coffee is produced. I am creating coffee beans with fewer flaws, at the very least.
As a result, wet-processed coffee is of more excellent quality and is, therefore, more expensive.
Coffee processing methods: The first step is to sort the coffee
The coffee beans are taken to the reception area after being picked and immediately placed in a tank full of water for sorting (for Specialty Coffee, this step is done as soon as possible to avoid dehydration). The heavy fruits will sink to the bottom of the tank (wet processing), while the dried, damaged fruits will float to the top. Branches, leaves, contaminants, and other debris are also removed from coffee.
Coffee beans that are “normal” will be denser and heavier than water. Defective pods, on the other hand, seedless or wormed, will generate voids, causing them to float on the water’s surface.
Step 2: Remove the rind in the second step
In the wet coffee processing procedure, this is the most critical step. The husking must be completed fast to minimize spontaneous fermentation and the production of odd flavors in the beans.
The coffee cherries are rubbed against the spindle, causing the peel (and some of the Mucilage) to split to one side, leaving the beans covered in a film of mucus on the other. Before being transferred to the aqueducts, coffee beans must be separated from their pods (incompletely hulled pods and some companion pods) using a floor or sieve.
The residual contaminants will float to the water’s surface and be removed to the utmost extent possible if you follow the course.
Step 3: Fermentation eliminates mucus in the third step
After the pods and other impurities have been removed, the coffee is placed in a water tank to begin the fermentation process. The amount of water used in processing varies, although it is typically 1:1. This is a crucial step in the wet processing process since it has a significant impact on the final flavor of the coffee. Due to a water shortage (or by choice) in some regions, fermentation can occur naturally without soaking the coffee in a water bath; this approach is known as semi-wet processing—honey processing (semi-washed).
More on the mucus layer (also known as Mucilage) – this is the actual meat of the fruit and is somewhat “stubborn” when milled away. With a complicated composition that includes water, polysaccharides, sugars, proteins, lipids, minerals, acids, and more, the pectinase enzyme system is the key (which helps to break down pectin).
With minimal mechanical effort, intrinsic fermentation of coffee cherries and microorganism engagement will enhance quick mucilage degradation. The fermentation process must be closely controlled to ensure that the coffee is devoid of unwanted flavors. The elimination of Mucilage through fermentation takes 12 to 36 hours for most coffees, depending on the temperature, mucilage thickness, and enzyme concentration.
When does the fermentation process end?
There is no longer a sticky, slippery sensation; instead, there is a sensation of “gravel,” and the husk’s roughness is complete. To do this, the coffee mass must be scraped by hand or machine (a process known as demucilage) so that the friction between the beans helps to remove the mucus surrounding the beans thoroughly. When the fermentation is finished, the coffee is thoroughly cleaned with clean water once more.
The fermentation’s end time is the deciding factor, but it isn’t set in stone. It is influenced by various elements, including the environment, production conditions, and desired flavor goals.
It’s challenging to maintain consistency in the face of so many variables. It’s not easy; some utilize sensory experience, while others use Brix (showing sugar content in a coffee sample) – usually 8°Bx (8 grams of Sucrose per serving) 100 grams of the model) paired with pH control of around 4.5 (according to O’Coffee from Brazil).
Step 4: Allow the coffees beans to dry
After rinsing the coffee bean with clean water, they are dried – the most popular way is to sun-dry the beans outside on a drying rack to reduce the moisture content to 10% -12%.
To promote uniform drying, the coffee should be piled from 2 to 10 cm and often stirred at this phase. After drying, they are now known as parchment coffee and will be packaged for storage or processed further in the refining process.
What kind of coffee can be wet-processed?
As previously said, wet processing uses a lot of water and necessitates more automated technology, which raises the price of raw green coffee. As a result, low-cost coffees, including Robusta, are rarely utilized in this process. To maximize flavor potential, wet or semi-wet processing will be used on Typica or Bourbon varietals with more excellent grain quality.
Because Robusta coffee beans have a far higher acid content than Arabica coffee. They produce a robust sour taste and unpleasant sensory experience when wet-processed hence most are processed dry.
One of the most common critiques of wet processing nowadays is its excessive water usage. This is an issue in places where water is scarce, but improper wastewater treatment can also pollute the environment. This has prompted coffee associations and growers to invest in more environmentally friendly wet processing methods.
What is pulped natural process coffee beans?
The skin of the coffee cherry is removed in the pulped natural process. During the drying process, the fruity mucilage remains intact. All plants produce mucilage, a thick, gelatinous material. In other words, the coffee is dried but the sticky fruit pulp remains attached. Because the pulp is frequently referred to as ‘honey,’ pulped natural coffee is also known as ‘honey washed’ coffee.
In some ways, the process is a balance between the dry (natural) and wet (washed) methods (where the beans are dried while still inside the fruit) (where all the soft fruit residue, including skin and pulp, are scrubbed off before the coffee is dried).
What are Honey processed coffees?
The coffees have a softer acidity than washed or wet-processed coffees, with fewer citrus notes and more chocolaty sweetness. They all have varied flavor profiles, which is most likely due to how different manufacturers conduct honey-processed coffees.
The method was developed in Brazil some 15 years ago and consisted of simply allowing the coffee to dry with almost all of the fruit pulp still attached to the beans. The honey/pulped natural procedure is still done this way in Brazil and Central America.