Coffee is a popular beverage loved by millions of people worldwide. However, caffeine, one of its main components, is not suitable for everyone for a variety of reasons, mainly health concerns. A big portion of the world population cannot simply tolerate increased caffeine levels in their bodies. Decaf coffee, fortunately, is accessible for those who want to experience the rich flavor and aroma of coffee without the caffeine.
Decaffeinating coffee is done when coffee beans are still raw or ‘green’. There are several methods that companies can use to remove caffeine from green coffee. One popular method is the Swiss water process, which employs water as the solvent rather than chemicals.
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We will look at what the Swiss Water Process is and how it works in this article.
WHAT IS SWISS WATER PROCESS?
Friedlieb Ferdinand Runge, a German chemist, discovered caffeine in 1819. Caffeine is a stimulant drug that is found in many beverages, including coffee. And, as early as the end of the nineteenth century, research was being conducted into ways to limit or even eliminate its effects while preserving the other components of coffee. One of the results of these researches was the Swiss water process.
The Swiss water process, which originated in Switzerland in 1933, is a natural method of decaffeinating coffee. This process utilizes only water and a specialized filter to remove caffeine from coffee beans without any chemical or solvent involved. For this reason, the Swiss water process is considered to be one of the most environmentally friendly methods of decaffeination, as it does not produce any harmful waste products
The method starts by soaking the the beans in boiling water to extract the caffeine and other soluble components. The resulting solution is then put through a specific filter, which eliminates the caffeine while preserving the taste components. The beans are then dried and roasted as usual. This yields decaf coffee with a lot of the original beans’ flavor and aroma. This method is regarded as one of the most natural and environmentally friendly methods of decaffeinating coffee.
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One of the advantages of the Swiss Water Process is that it may extract caffeine from coffee beans while leaving the other desirable compounds intact. As a result, the resulting decaf coffee might have a full, rich flavor profile similar to regular coffee.
HOW IS IT DONE?
To extract caffeine and other desired flavor components, a batchof green coffee beans is soaked in water at a high temperature during the Swiss water process. The process necessitates the immersion of beans in water with temperatures between 160°F (71°C) to 210°F (99°C) to eliminate the caffeine-containing oils.
Water containing all of the compounds is filtered through a carbon filter. This collects just the caffeine molecules, which are larger than the other molecules. The batch of green coffee that has been stripped of caffeine, flavor molecules, and other desirable components is discarded.
A second batch of green coffee is soaked in water that contains the soluble components from the first batch, which can now absorb just caffeine. As a result, the taste components of the second batch will remain in the beans. The water is then re-filtered to eliminate the caffeine before receiving the third batch of green coffee. After that, the second batch is dried.
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After being decaffeinated, coffee beans can be used to make half-caffeinated coffee, which is simply manufactured by combining caffeinated and decaffeinated beans.
HOW WATER ALONE DECAFFEINATES COFFEE BEANS?
It’s not particularly surprising how water eliminates caffeine from coffee. The Swiss water process employs diffusion to accomplish this. Diffusion refers to the movement of particles or molecules from an area of high concentration to an area of low concentration. In the Swiss Water Process, caffeine molecules within the coffee beans migrate from a region of higher concentration to a lower concentration area, which is the coffee extract, in order to extract caffeine.
Because caffeine molecules are more soluble in water than the other flavor compounds in coffee beans, the diffusion mechanism in the Swiss water process works. When coffee beans are soaked in hot water, caffeine molecules transfer from the beans to the water, resulting in a caffeine-rich coffee extract. When this extract is passed through a carbon filter, the caffeine molecules become trapped, leaving the flavor compounds behind. The filter is porous to allow molecules, including water and coffee solids, but not caffeine, a relatively large molecule.
The filtered extract is then used to soak a new batch of green coffee beans, and the caffeine molecules in the extract diffuse into the beans, replacing those lost during the previous cycle. This cycle is repeated until the desired level of decaffeination is reached. The diffusion mechanism guarantees that the coffee beans are not over-soaked, and that the flavor components are not totally eliminated. This results in a decaf coffee that tastes and smells very much like regular coffee.
References:
S. Racineux, C. Tran (2018). Coffee Isn’t Rocket Science: A Quick and Easy Guide to Buying, Brewing, Serving, Roasting, and Tasting Coffee. Black Dog Publishing.
J. Frisks (2016). Coffee: Everything You Ever Wanted to Know About Coffee. Create Space Independent Publishing.
