02/22/2024
The decaffeination process may seem like a necessary evil & is all about removing the caffeine while trying to leave behind as many other compounds as possible! But how exactly does that happen?
Well, there are 3 different methods…
☕️ Water process (think Swiss Water): this the most common process and uses water that has been super saturated with soluble coffee compounds minus the caffeine. This solution is known as Green Coffee Extract, or GCE. This GCE creates a gradient for the caffeine which allows to flow from the bean with high concentration to the solution with low concentration. The idea is that since the solution is saturated with coffee compounds the other compounds aside from the caffeine should in theory stay in the bean and be unaffected by the process.
☕️ Solvent process: this is similar to the water process but instead of using water and creating a GCE a chemical solvent is used, methyl chloride or ethyl acetate. Both solvents are safe and don’t add any flavor. Once the caffeine is removed the beans the solvent is rinsed off. This process can be also be done indirectly where water is used to strip the beans of all soluble compounds. That water reacts with the solvent remove the caffeine. The solvent is stripped from the water and then the water is introduced back to the bean so the soluble compounds can be reabsorbed.
☕️ Carbon Dioxide process: The green coffee beans are soaked and then placed in an extractor. The extractor is then filled with pressurized “supercritical” carbon dioxide (CO2). At the pressures used supercritical CO2 becomes fluid fluctuating between a gas and liquid. At this point the caffeine begins to migrate to the CO2. The CO2 is then passed through a caffeine absorbing filter. It is then depressurized returning to gaseous form.
No process is perfect and they all affect the end flavor in different ways. But it has been proven that during the solvent method soluble compounds in addition to caffeine are removed so this method does have a larger impact on the end flavor, than the other two.
Have you ever had a “good” decaf coffee? Tell us about it below, 👇 I’ll go first!
