Περιγραφή
Sugar cane, which is widely grown in Colombia, is used in this process as a „natural“ source of ethyl acetate. First, the sugar cane molasses is fermented. The ethanol produced in the fermentation process is then mixed with acetic acid. The result is ethyl acetate, which is used in the decaffeination process itself. In the meantime, the green coffee from which we want to remove the caffeine is prepared. The beans are steamed at low pressure to enlarge their pores and make them more permeable. Then we move on to the actual caffeine leaching process. The coffee is washed with water in which the ethyl acetate has dissolved. This compound replaces the caffeine in the molecular structure and it is released into the liquid.
The process is repeated several times until at least 97 % of the caffeine has been removed from the coffee. Once this limit is reached, the coffee beans are steamed again to get rid of the ethyl acetate residue. The steaming temperature is around 70 degrees and even if there is a trace amount of ethyl acetate left in the coffee, it can easily be got rid of during the roasting process.
The coffee is then re-dried to a desired moisture content of between 10 % and 12 %. Drying is often carried out in vacuum drum dryers.
