Carbonic Maceration in Coffee Processing: There are a variety of experimental processing methods in coffee, each of which has the potential to affect the unique qualities of coffee, including black honey, malic fermentation, and frozen natural.
Winemaking, which employs the procedure of maturing grapes before crushing, is the origin of Carbonic Maceration. Like wine, other elements, such as terroir, frequently dictate how much carbonic Maceration impacts a coffee’s flavor. However, for roasters, it is often a successful strategy for building their brand and differentiating themselves from rivals.
Please continue reading to learn more about carbonic Maceration and how specialty roasters may utilize it to differentiate their coffee from their competitors.
What is carbonic Maceration in Coffee Processing?
Carbonic Maceration is a very catchy phrase 🤣Listen to coffee being prepared by the carbonic maceration method, you don’t need to know what it is, but, like Anaerobic fermentation, this is a very easy-to-understand process:
Carbonic (adjective) = have carbon
Maceration (noun) = softening, tempering, soaking, natural decomposition
➜ Carbonic Maceration translates as “decomposition/incubation/immersion in CO2 atmosphere.”
Carbonic Maceration is a phrase borrowed from winemaking. With carbonic Maceration, the whole grape (which may include the stem) is soaked in a container, and CO2 is injected to expel the oxygen. Grapes are fermented before being crushed to make wine.
Carbonic Maceration differs from conventional winemaking in that the grapes are crushed and the skins removed before the rest of the grapes are fermented to produce alcohol. Carbonic Maceration produces wines with high fruit flavors and low tannins, so the wine is sweeter and less dry.
Close to Carbonic Maceration is the Semi-carbonic maceration (SCM) method. With SCM, the grapes are fermented in tanks that are not pumped with CO2. Since the layer of grapes on top is heavy enough to crush and crush the layer of grapes below, the grape juice slowly flows out. The fermentation process accelerates and produces CO2, causing the upper layer of grapes to go through the Carbonic Maceration stage.
Carbonic Maceration is not a new technique or requires high technology. Much of the wine in the Beaujolais region, France, is made using this method. Wines from Beaujolais became popular in the 60s and began to spread worldwide; This technique has also become familiar to many winemakers in Australia and the United States.
In a nutshell, Carbonic Maceration is simply a technique of fermenting grapes to make wine. As mentioned in the previous post, microorganisms, including yeast, break down sugars to produce energy, gases (hydrogen, CO2), alcohols (ethanol, butyl alcohol), acid groups, etc. Therefore, when Carbonic Maceration is applied to the preliminary processing of coffee, this is just a phrase used to describe the fermentation process of coffee.
Carbonic Maceration in coffee processing
Carbonic Maceration has only been applied in coffee processing in recent years. Saša Šestić, the 2015 World Barista Championship winner, was probably the first to popularize the term. Saša won WBC 2015 with a Sudan Rume-like coffee prepared with the Carbonic Maceration washed method.
Saša says Tim Kirk of Clonakilla Winery in Canberra was the one who helped him understand more about winemaking techniques and gave him ideas on how to apply winemaking techniques to coffee preparation. In addition to understanding carbonic Maceration, Saša learns processes for controlling temperature, CO2, humidity, pH, and alcohol content .
According to Saša, an environment with a lot of CO2 makes the whole coffee ferment slower; the pH does not increase suddenly. If washed coffee is usually fermented for 7-12 hours, Carbonic Maceration lots can ferment for three days or more.
In the Carbonic Maceration process, the temperature is controlled: the lower the temperature, the longer the fermentation process. Saša said that coffee has high acidity at low temperatures (4-8°C). The coffee lot is sweet and full of Carbonic Maceration at 18-22°C.
Carbonic Maceration is often considered a step in coffee processing. After the coffee is fermented with Carbonic Maceration, the cherries can be dried (naturally processed), peeled, and then washed.
How is carbonic Maceration different from anaerobic fermentation?
As the previous article said, anaerobic fermentation (or, more precisely, “fermentation in an environment without oxygen”) is fermenting coffee in an oxygen-free environment. Carbonic Maceration resembles AF in the absence of oxygen. With AF, the CO2 generated during fermentation escapes through the one-way valve. With Carbonic Maceration, CO2 is pumped into the tank from the very beginning.
In addition, there are many variations of Aerobic Fermentation. Natural AF means that the whole cherries are fermented, but washed AF means that the skin and flesh of the coffee have been cleaned before. With Carbonic Maceration, the outer skin of the coffee is preserved (just like the skin of grapes is preserved). HOWEVER, Project Origin recently introduced some MC lots with washed coffee before starting Carbonic Maceration.
Like Aerobic Fermentation, Carbonic Maceration coffee is usually stored in steel tanks/tanks. Farmers everywhere have been experimenting with AF and Carbonic Maceration in plastic bags or containers. Some farmers also devised the Carbonic Maceration method with water (coffee soaked in water + CO2 gas) instead of dry fermentation with only CO2.
What about the taste? Saša Šestić won WBC 2015 with Carbonic Maceration coffee, so this method only produces good coffee? As mentioned many times, it is impossible to judge the taste of coffee by looking at the preliminary processing. Carbonic Maceration is a method that has a practical basis (when looking at the wine industry) and a scientific basis (when it comes to understanding fermentation and its products).
Fermented coffee usually has a higher sweetness and a thicker body. With a lot of CO2 and low temperatures, microorganisms break down sugar more slowly; metabolism slows down, and acid and alcohol groups are not produced too quickly.
When well-controlled, carbonic Maceration can make good quality coffee with delicious and exotic notes like maple syrup, bubblegum, raspberries, passion fruit, rose, pineapple, watermelon, and violets.
Regardless of the message, the pre-processed coffee with the Carbonic Maceration step seems to have an evident and prominent note. The slow fermentation is the basis that Carbonic Maceration coffee does not have many messages in favor of the ‘over fermented’ taste that is often said to be a defect.
Carbonic Maceration, anaerobic fermentation and the future of coffee
With Helena Coffee Vietnam, good coffee is the coffee you like. With each type of coffee, we don’t emphasize what kind of coffee it is, how it is prepared, or how much it costs. New initiatives and experiments are essential for the coffee industry to thrive.
However, for sustainable development, farmers need access to an efficient, inexpensive way of processing that produces delicious and easily repeatable coffee. That’s why we’re always ready to support new techniques and methods. But different from progress, complexity does not mean high quality; strange is not necessarily liked by many people.
Experimenting with Carbonic Maceration or Aerobic Fermentation is an opportunity for the specialty coffee industry to look back and better understand the fermentation process and how microorganisms can elevate coffee quality. There are many ways to get there: AF is expensive, and Carbonic Maceration is a brutal way to control. But it is very likely that simple pre-processed coffee can be just as delicious with just fermentation in water and then drying on the rig.
Some farms can soak coffee in ice water or come up with new ways, such as soaking ground coffee with coffee pods or fermenting coffee with fruit – but in the end, the best way to prepare coffee is always the way to save money. Economical, simple, easy to make, easy to control, and makes good coffee.