Coffee Origin: South American
Coffee Certification: Fair Trade Organic and Bird Friendly
There are essentially two methods, known as direct and indirect. They both operate on the physics principle of diffusion: a substance will move from an area of high concentration to an area of low concentration.
In direct solvent decaffeination, coffee is hydrated (either via steam, immersion, or both) and then repeatedly rinsed with the liquid chemical. The coffee comes into direct contact with the Ethyl Acetate or Methylene Chloride, hence the term “direct.” On each pass, the solvent, now laden with caffeine, is distilled to remove caffeine. The process is repeated until the coffee is ready to be cleansed with water and re-dried.
In the indirect method, coffee is soaked in warmed water. The liquid is then drained, and chemical solvents are added to the liquid solution to remove the caffeine, but they never come into direct contact with the coffee itself. The decaffeinated coffee extract slurry is then reintroduced to the original coffee to re-saturate the beans with flavor. This is repeated until the coffee is sufficiently decaffeinated and ready to be re-dried.
Water-processed decaffeination starts out the same way as the indirect solvent method using coffee solids, except that after the coffee extract water absorbs the coffee’s caffeine, the caffeinated liquid is simply passed through filters. In Swiss Water’s patented method, the filters are activated charcoal, for example. Note that because caffeine extraction does not use synthetic solvents, it is less efficient, which has traditionally made it more expensive.