The Swiss Water Process of decaffeinating coffee beans is a chemical-free method developed in Switzerland during the 1930’s by the Swiss Water Decaffeinated Coffee Company (SWDCC), and employed today at the world’s only Swiss Water decaffeination facility, in Vancouver, Canada.
The process involves soaking unroasted green beans in hot water to release caffeine, whilst retaining the beans’ natural flavours. The process takes its starting point from the composition of a green bean; a typical bean will be composed of around 74% insoluble materials, and 26% soluble ‘flavour components’, including around 1.20% caffeine.
The process allows caffeine and coffee solids to be separated from the bean during the hot water soak, after which the insoluble green bean is discarded, and what remains is a caffeinated solution which has retained the flavour-filled coffee solids. In order to remove the caffeine the solution is passed through a carbon filter, which traps caffeine components but allows the solids to pass through. The resulting solution is known as ‘flavour-charged water’ – a liquid composed of 25% coffee solids, with all the flavour of coffee but without the caffeine kick.
This solution can now be used to actually create decaffeinated coffee beans. Quality green coffee beans are soaked in water in order to expand them in size, preparing them for caffeine extraction. The expanded beans are then immersed in the ‘flavour-charged’ water solution, which runs through another filtration device. As there is no caffeine in the ‘flavour-charged’ water, caffeine actually diffuses from the green beans and is released into the ‘flavour-charged’ solution.
Because the composition of soluble, flavour-filled components in both the beans and the ‘flavour-charged’ water is equal, only the caffeine is removed from the bean during this second filtration process, leaving the bean’s flavour intact. The ‘flavour-charged’ solution, now full of the beans’ caffeine components, flows cyclically through a carbon filter, which has been specifically modelled to only trap the small caffeine particles, and not the flavour solids. This caffeine-free water then passes back through the bean numerous times, repeating this process until almost all the caffeine has been removed from the bean, and is trapped by the carbon filter. This process takes around 8 hours to complete, and leaves the bean around 99.9% caffeine-free.
This process is unique in that it is performed without the use of any chemicals. Shockingly, almost 80% of branded, decaffeinated beans on the market use chemicals to remove the caffeine. These chemicals include Methylene Chloride and Ethyl Acetate, both of which can be employed in processes known as the ‘Direct’ and ‘Indirect Methods’. The Direct Method involves immersing beans into a caffeine absorbing chemical solvent. The caffeine-saturated solvent is then removed from the beans, and purged of its caffeine content. The beans are then placed back into the now caffeine-free solvent, and the process is repeated until the beans are themselves caffeine-free. The Indirect Method works similarly, but involves the solvent be employed at a later stage in the process; the beans are soaked in water, which is mixed with the solvent one the beans are separated, thus removing caffeine from the water which is re-used repeatedly on the beans.
These chemical-based methods sometimes go by different names; the ‘European Method’, the ‘Natural Process’, or the ‘Water Process’.
These terms, however, should never be confused with the chemical-free Swiss Water Process, which is still recognized world-wide as the most beneficial and natural decaffeination process in use today.
