Description

Most folk know about the Water Process method of decaffeinating coffee beans but there is a lovely alternative and natural process using CO2.

And this is how it is done.

The green beans are put into a ‘pre-treatment’ vessel where they are washed and hydrated with water before being brought into contact with pressurised liquid carbon dioxide. Once the green coffee beans absorb the water, they expand and the pores are opened allowing the caffeine molecules to become mobile.

After the water has been added, the coffee beans are then brought into contact with the pressurised liquid carbon dioxide which, when combined with water, basically forms a sparkling water. The carbon dioxide circulates through the beans and acts like a magnet, drawing out those mobile caffeine molecules.

The sparkling water then enters an evaporator which triggers and releases the caffeine rich carbon dioxide out of the water. The now caffeine free water is pumped back into the vessel for a new cycle.

This cycle is repeated until the remaining caffeine has reached an acceptable level. Once this has happened, the circulation of carbon dioxide is stopped and the green beans are discharged into a drier.

The now decaffeinated coffee is then gently dried until it reaches its original moisture content, and it is now ready for roasting.