Mountain Water process
In the decaffeination process, the green coffee beans are immersed in water in order to extract the caffeine. The water contains the soluble components of the coffee beans which holds the elements of the flavour, so that, during the extraction of the caffeine the beans maintain their original components.
To separate the caffeine from the water containing the soluble components, the water passes through a special filter which removes the caffeine. This results in “coffee solid solubles charged water” saturated with the flavor components but free of caffeine, which is used again in the extraction process.
Carbon Dioxide (CO2) process
This process is technically known as supercritical fluid extraction. With the CO2 process, beans are soaked in a liquid bath of preassurized carbon dioxide, this removes the caffeine . After a thorough soaking, the C02 is removed and the pressure is reduced allowing the CO2 to evaporate, or the pressurized CO2 is run through charcoal filters to remove the caffeine. The coffee beans are then allowed to dry naturally.
CO2 works better than water because it is kept in supercritical state near the transition from liquid to gas so that they have the high diffusion of gas and the high density of a liquid. This process has the advantage that it avoids the use of potentially toxic solvents.
*photo courtesy of www.sweetmarias.com/decaf.co-2method.html
Why we use the processes we do
The World Health Organization found methylene chloride, the main solvent used in non-natural decaffination processes, to be a toxic chemical with effects such as reversible central nervous system depression and carboxyhaemaglobin formation. Additional effects reported were liver and renal dysfunctions, hematological effects, and neurophysiological and neurobehavioral disturbances. (The WHO Environmental Health Criteria Series, volume 164.)
The dangers of Methylene chloride in roasted coffee are debated as it evaporates at 104 degrees F (40 degrees C), and so would not survive the roasting process. Though residual methylene chloride does not appear to be present in roasted decaffeinated coffee, the chemical itself is dangerous to health so our organic certification does not allow it.
Did you know?
~ That Bean North uses Arabica coffee beans which have between 80-100 mg of caffeine per 5 oz. cup and
~ Robustas (your typical grocery store brand. Nabob, Folgers etc.) have up to 150-175 mg per 5 oz. cup!
~ The darker the coffee, the less caffeine. For example, a dark or French roast coffee has less caffeine than a medium roast coffee.
~ Espresso coffee has between 60-80 mg of caffeine per serving.
~ Coffee must have 97% of its caffeine removed to qualify as a decaffeinated coffee.
~ If 97% of the caffeine is removed from a Robusta bean (your Nabob, Folgers, Maxwell House, etc.) it will still a have more caffeine that the decaffeinated Arabica beans offered at Bean North.
~ Coffee beans have the caffeine removed before they are roasted, with the least effect on the flavour of the beans.