Coffee Decaffeination

Coffee Decaffeination

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decaf processDecaffeination means the process of extracting caffeine from the coffee beans, mate, cocoa, tea leaves and other caffeine-full substances. Please note that the term "decaffeinated" drinks doesn't mean they are free of caffeine. As recent studies prove, the majority of decaffeinated drinks still have caffeine in the amount of 1%-2%.

There are several methods of decaffeination. The general idea is the following: the coffee beans are first steamed of and then washed out with a special dissolving. The process is repetitive and lasts for 8-10 times until almost totally cleaned. Though caffeine is extracted from the beans, there still remain other necessary chemicals.

Roselius process

The process was created by Ludwig Roselius and Karl Wimmer in 1903. It is the first commercially successful way of decaffeination which was adopted by such companies as Kaffee HAG (Kaffee Handels-Aktien-Gesellschaft in past) in Europe and Café Sanka in France. The process implied steaming coffee beans with a pickle (salt water) and then using benzene as a solvent to eliminate caffeine. However, later those companies decided to abandon this method as benzene is dangerous for health.

decaffeinationSwiss Water Process

The process was invented in 1930’s by a Swiss company of the same name - Swiss Water Decaffeinated Coffee Company. A portion of green coffee beans is soaked into hot water, thus freeing them from caffeine. When caffeine and coffee solids gets into coffee, the beans are extracted. That water then goes through a carbon filter which catches caffeine but let the coffee dry substances pass through. The obtained solution, named “green coffee extract (GCE)” by the company itself, is now available for coffee decaffeination. This extract passes through carbon that traps caffeine. The process is repeated for several times until 99.9% of caffeine is removed from beans.

Direct method

This method is known for steaming coffee beans for 30 minutes and then rinsing them with either dichloromethane or ethyl acetate for 10 hours. The liquid is then withdrawn and the beans are subjected to additional 10 hours evaporation – to emit any remaining solvent.

Ethyl acetate can be gained from various fruits or vegetables, that’s why coffee decaffeinated with the help of this liquid can be related as naturally processed. However, due to inefficacy of receiving it in a natural way, ethyl acetate used in this method is rather synthetic than natural.

Indirect method

Coffee beans are soaked in hot water for a several hours resulting in a strong cup of coffee. Then the beans are extracted from this liquid and again either dichloromethane or ethyl acetate is used to remove caffeine. Caffeine can be eliminated by a simple vaporization. The same water can be used with a new portion of beans going through this two-step process. This way, caffeine is the only substance removed, that’s why this process is also called as “water-processed”, despite using some chemicals as well.

CO2 process

The decaffeination method is formally known as supercritical fluid extraction (A supercritical fluid is any substance at a temperature and pressure above its critical point - Wikipedia). The already steamed beans are soaked in a solution of supercritical carbon dioxide at a pressure of 73 to 300 atmospheres. After 10 hours of thorough soaking, the pressure is lowered, so that CO2 vaporizes, or pressurized CO2 is let through either water or charcoal filters to eliminate the caffeine. The carbonic acid is then used with another batch of coffee beans. The method is considered to be more useful than the “water-processed” one and avoids using any harmful dissolving.

caffeine contentTriglyceride proess

Another process using green coffee beans soaking in hot water. However it differs from the processes described above and implies the following act of removing caffeine. Coffee beans are soaked in a hot water or coffee solvent until caffeine comes to the surface of the beans. After that they are relocated into another container and are absorbed in coffee oils received from coffee grounds being in use before.

After some time of high temperature, the triglycerides in the oils eliminate the caffeine (without affecting coffee flavors). The beans are detached from the oils afterwards and dried. The oils are then rid of caffeine in order to be used with another batch of beans. This method is also known as direct contact way of decaffeination.


Naturally caffeine-free plant Coffea charrieriana, a Coffea Arabica was found in 2004. The term “decaffito” was created to describe this type of coffee sold in Brazil. The plant has a defective gene caffeine synthase which makes it collect theobromine instead of converting it to caffeine.

See also:
Coffee Benefits and Side Effects
Coffee plus Tea?
Coffee Substitute
Health and Fitness
Organic Coffee
see also

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